2nd gen mystery electrical problem solved + write-up
05-01-2010, 11:17 AM
#62
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good thread i have had the mentioned problems on my 3rd gen with the big 3 upgrade. at first i thought it was my amps so i added a 5farad power cap that helped alot but the brakelights still bring down the voltage more than i would like. i will have to try this to see if works for 3rd gens
06-19-2010, 08:59 PM
#64
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I spent a couple hours this fine Saturday afternoon on this mod.....
Actually I don't really have any low-voltage symptoms. My '92 Runner 4WD has only 116K on it and I had already cleaned the corrosion off the battery terminals/posts/clamps about six months ago when I put a new battery in it. So I completed this mod as more of a preventative measure rather than to fix any problems/issues. It was just the excuse I needed to go work on the truck
First I went down to the local welding supply shop and picked up a couple feet of both 2-gauge and 4-gauge welding cable figuring that I would use one to replace the fuse box-to-positive post wire, and the other to replace ground wires. I also stopped at the hardware store and picked up some big ol' 4g copper ring terminals.
Long story short: I replaced the OEM 10-gauge white wire (with the 16-gauge blue wire attached as per Sludge's photo on page 1 of this thread) with the new 4-gauge wire, then replaced the OEM 12-gauge black ground wire off the negative battery terminal with 6 inches of 2-gauge flexible welding wire. It took about 2 1/2 to 3 hours to take apart the fuse box, cut the wires to the right length, attach the ring terminals with shrink insulation, (I spent the time and did it right!) replace the grounds, clean everything up and then reassemble. I was a little leery of taking that fuse box apart but after looking at tysen86's photos (above), I felt confident to try it. I'm glad I did.
Total Cost = $15. . . . . . . . . Unfortunately, I didn't think about taking photos until just now!
The results? My headlights & dash lights are noticeably brighter and all of my windows seem to roll up/down a little faster (including the rear window which is most certainly faster). And my radio suddenly found some bass! I don't really notice any performance improvement, but again the 3VZE only has 116K on it and I've already done the ISR mod, drilled holes in the airbox, blocked off the EGR, seafoam, and just about every other performance mod listed on Yotatech with the exception of headers (i'm saving for 'em... probably this fall!)
I agree that this is a worthwhile mod even if you aren't experiencing any noticeable electrical symptoms. But in my opinion it is probably enough to just replace that blue wire from the positive terminal and connect it to the original 10-gauge white wire that runs underneath the fuse box. It is much simpler to replace that 3 inches of blue 16-gauge wire and splice in an extra 3-4 inches of new 10-gauge rather than tearing your fuse box apart. Simply remove the wire from the positive terminal battery clamp, slide off the grey protective wrap, then unwrap the black insulation covering the white-to-blue wire connection. Be forewarned: whatever Toyota used to insulate the blue/white connection is A BLACK STICKY MESS!! It'll stick to your hands and everything else for the rest of the day!
For the ground wire I just attached one end of the 2-gauge wire (overkill, i know) to the negative battery crimp and the other end to where the ground wire was originally screwed in to (inside the passenger side fender about 4 inches away from the battery). Since the 2-gauge is so d*mn thick, I wound up splitting the end of the wire in half and using two ring terminals and screwing both into the fender. Fortunately, there was already a hole nearby to screw into. Now I am all set up for a AES high-output alternator as per OutlawMike's thread here.
I also took Rather_Diesel's advice and sandpapered the paint off the inside fender before attaching the new ground wire connections.
So if your bored and looking for a reason to work on your truck, this is probably the mod for you. Don't be afraid of the fuse box but if you don't want to hassle with it, take the short cut and just replace the skinny blue wire off the positive terminal. But if you do open the fuse box, make sure you seal it up when your done to keep water out of it (since it is just a few inches away from the front passenger side inner fender) because it does get wet/muddy in there (again, see tysen86's photo!) I used 4-gauge wire and that's as big as you can fit while still being able to close up the fuse box tight (if you use 2-gauge, you're gonna hafta cut the opening bigger to get it to fit).
Hey thanks again guys for the advice and mods.
Keep 'em coming!! 
-Tom
Actually I don't really have any low-voltage symptoms. My '92 Runner 4WD has only 116K on it and I had already cleaned the corrosion off the battery terminals/posts/clamps about six months ago when I put a new battery in it. So I completed this mod as more of a preventative measure rather than to fix any problems/issues. It was just the excuse I needed to go work on the truck
First I went down to the local welding supply shop and picked up a couple feet of both 2-gauge and 4-gauge welding cable figuring that I would use one to replace the fuse box-to-positive post wire, and the other to replace ground wires. I also stopped at the hardware store and picked up some big ol' 4g copper ring terminals.
Long story short: I replaced the OEM 10-gauge white wire (with the 16-gauge blue wire attached as per Sludge's photo on page 1 of this thread) with the new 4-gauge wire, then replaced the OEM 12-gauge black ground wire off the negative battery terminal with 6 inches of 2-gauge flexible welding wire. It took about 2 1/2 to 3 hours to take apart the fuse box, cut the wires to the right length, attach the ring terminals with shrink insulation, (I spent the time and did it right!) replace the grounds, clean everything up and then reassemble. I was a little leery of taking that fuse box apart but after looking at tysen86's photos (above), I felt confident to try it. I'm glad I did.
Total Cost = $15. . . . . . . . . Unfortunately, I didn't think about taking photos until just now!
The results? My headlights & dash lights are noticeably brighter and all of my windows seem to roll up/down a little faster (including the rear window which is most certainly faster). And my radio suddenly found some bass! I don't really notice any performance improvement, but again the 3VZE only has 116K on it and I've already done the ISR mod, drilled holes in the airbox, blocked off the EGR, seafoam, and just about every other performance mod listed on Yotatech with the exception of headers (i'm saving for 'em... probably this fall!)
I agree that this is a worthwhile mod even if you aren't experiencing any noticeable electrical symptoms. But in my opinion it is probably enough to just replace that blue wire from the positive terminal and connect it to the original 10-gauge white wire that runs underneath the fuse box. It is much simpler to replace that 3 inches of blue 16-gauge wire and splice in an extra 3-4 inches of new 10-gauge rather than tearing your fuse box apart. Simply remove the wire from the positive terminal battery clamp, slide off the grey protective wrap, then unwrap the black insulation covering the white-to-blue wire connection. Be forewarned: whatever Toyota used to insulate the blue/white connection is A BLACK STICKY MESS!! It'll stick to your hands and everything else for the rest of the day!
For the ground wire I just attached one end of the 2-gauge wire (overkill, i know) to the negative battery crimp and the other end to where the ground wire was originally screwed in to (inside the passenger side fender about 4 inches away from the battery). Since the 2-gauge is so d*mn thick, I wound up splitting the end of the wire in half and using two ring terminals and screwing both into the fender. Fortunately, there was already a hole nearby to screw into. Now I am all set up for a AES high-output alternator as per OutlawMike's thread here.
I also took Rather_Diesel's advice and sandpapered the paint off the inside fender before attaching the new ground wire connections.
So if your bored and looking for a reason to work on your truck, this is probably the mod for you. Don't be afraid of the fuse box but if you don't want to hassle with it, take the short cut and just replace the skinny blue wire off the positive terminal. But if you do open the fuse box, make sure you seal it up when your done to keep water out of it (since it is just a few inches away from the front passenger side inner fender) because it does get wet/muddy in there (again, see tysen86's photo!) I used 4-gauge wire and that's as big as you can fit while still being able to close up the fuse box tight (if you use 2-gauge, you're gonna hafta cut the opening bigger to get it to fit).
Hey thanks again guys for the advice and mods.
Keep 'em coming!! -Tom
Last edited by GO_BLUE!; 06-19-2010 at 11:30 PM.
06-19-2010, 09:41 PM
#66
Registered User
84-88 4Runners also have this same poor design as the newer 4Runners, so i replaced that wire on my 86 4Runner with a piece of 4 gauge battery cable, because i plan on adding a winch and extra lights in the future.
06-20-2010, 12:03 AM
#67
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The original design probably wasn't too bad for a stock bare bones truck. I don't think the Toyota engineers had the foresight to envision all the new electrical gadgets we add to our trucks over the last 20-30 years. Just think of all the things that have been invented since your truck was built: GPS, Sirius/XM Satelite radio, cell phone chargers, bluetooth headset chargers, Mp3 players, headrest DVD players...etc. I've added most of these toys as well as a 750W power inverter, hilux tilt gauge, car alarm, Hella lights, and a Pioneer deck/amps/speakers. Plus I already had power windows/mirrors/sunroof/rear wiper..etc. Hell I even have a 12V cooler that I plug in once in a while.
All of which draw from the original electrical setup.(This reminds me of that Simpsons episode where Homer adds a fridge, fax, deep fryer, snowcone machine, fog machine, & Lite Brite to his car. . . . "save me chaka kahn, CHAKA KAHNNNN!")
If you add a winch, light bar, onboard air, CB, subwoofer, and/or extra lights/gauges (or Lite Brite
), then this mod is practically a must do. At least replace that skinny blue wire. A higher output alternator probably is a good idea as well. Because Who knows what new toys we'll want to add to our trucks in the future! 
Last edited by GO_BLUE!; 06-20-2010 at 12:48 AM.
06-20-2010, 09:17 AM
#69
Registered User
The original design probably wasn't too bad for a stock bare bones truck. I don't think the Toyota engineers had the foresight to envision all the new electrical gadgets we add to our trucks over the last 20-30 years. Just think of all the things that have been invented since your truck was built: GPS, Sirius/XM Satelite radio, cell phone chargers, bluetooth headset chargers, Mp3 players, headrest DVD players...etc. I've added most of these toys as well as a 750W power inverter, hilux tilt gauge, car alarm, Hella lights, and a Pioneer deck/amps/speakers. Plus I already had power windows/mirrors/sunroof/rear wiper..etc. Hell I even have a 12V cooler that I plug in once in a while. All of which draw from the original electrical setup.
(This reminds me of that Simpsons episode where Homer adds a fridge, fax, deep fryer, snowcone machine, fog machine, & Lite Brite to his car. . . . "save me chaka kahn, CHAKA KAHNNNN!")
If you add a winch, light bar, onboard air, CB, subwoofer, and/or extra lights/gauges (or Lite Brite), then this mod is practically a must do. At least replace that skinny blue wire. A higher output alternator probably is a good idea as well. Because Who knows what new toys we'll want to add to our trucks in the future!
All of which draw from the original electrical setup.(This reminds me of that Simpsons episode where Homer adds a fridge, fax, deep fryer, snowcone machine, fog machine, & Lite Brite to his car. . . . "save me chaka kahn, CHAKA KAHNNNN!")
If you add a winch, light bar, onboard air, CB, subwoofer, and/or extra lights/gauges (or Lite Brite
), then this mod is practically a must do. At least replace that skinny blue wire. A higher output alternator probably is a good idea as well. Because Who knows what new toys we'll want to add to our trucks in the future! I have a 100 amp alternator that i will be installing in the future, and a cb radio. I also have a nice fridge that runs on 12 volts or 110 volts, so once a add a plug to the rear cargo area of my 4Runner i will be able to plug it in and use it.
07-28-2010, 10:26 AM
#70
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Wow im glad i came across this thread, i will be doing this mod tonight...... im having the same issues with the radio and all the lights dimming, thanks man
08-05-2010, 02:42 PM
#71
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Thread Starter
Bump 
Found some of the original pics in an old email and re-hosted them and updated the posts..still missing one pic that showed the stock parts witht the mod parts side by side
that one pic was worth a 1,000 words of write up too.
Found some of the original pics in an old email and re-hosted them and updated the posts..still missing one pic that showed the stock parts witht the mod parts side by side
that one pic was worth a 1,000 words of write up too.
10-06-2010, 08:57 AM
#72
Registered User
Let the necroposting continue.
Thanks from yet another member for this useful info. I had thought my problem to be due to my conversion to an electric fan. (I always had light dimming issues but nothing impacting the motor) Thinking I just needed more current, I ordered a 70 amp alt, it came in last night. This weekend when I install it, I'll also replace that wire.
Thanks from yet another member for this useful info. I had thought my problem to be due to my conversion to an electric fan. (I always had light dimming issues but nothing impacting the motor) Thinking I just needed more current, I ordered a 70 amp alt, it came in last night. This weekend when I install it, I'll also replace that wire.
11-16-2010, 12:23 AM
#73
Found a link to this thread this afternoon in the 'cheap mods' thread, thought "hey, that sounds like crap that I have to deal with" and did the mod after dinner.
91 PU 3vze
I used 4ga wire for everything.
I replaced the positive wire going into the fuse box.
I didn't have the time/energy to do the alt cable, but mine looks solid, and never given me any trouble to my knowledge.
I snipped the ground cable below the split, and put on a new body ground, and ran an additional engine ground (left the old one) to the engine lift hook thinger.
I'm installing Sylvania SilverStar's tomorrow, so I'll post again with how that goes and if things seem peachy on a test drive.
Thanks for the great "why didn't I think of that" idea.
Edit: Having all sorts of trouble with idle, low-end power, hard start. Going to triple-check back over everything. Could be completely unrelated, not sure yet.
91 PU 3vze
I used 4ga wire for everything.
I replaced the positive wire going into the fuse box.
I didn't have the time/energy to do the alt cable, but mine looks solid, and never given me any trouble to my knowledge.
I snipped the ground cable below the split, and put on a new body ground, and ran an additional engine ground (left the old one) to the engine lift hook thinger.
I'm installing Sylvania SilverStar's tomorrow, so I'll post again with how that goes and if things seem peachy on a test drive.
Thanks for the great "why didn't I think of that" idea.
Edit: Having all sorts of trouble with idle, low-end power, hard start. Going to triple-check back over everything. Could be completely unrelated, not sure yet.
Last edited by ChzSoda; 12-08-2010 at 07:23 PM.
06-10-2011, 06:16 AM
#74
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Okay - Been been chasing a low 250rpm idle when hot. I didnt have noticable headlight dimming issues as my headlights are HID BUT I did noticed when using my rear window, or any windows in my truck that I had a minor voltage drop on the indicator.
I came across this post in the "Show us your best cheap mods section" and decided to investigate. Well; low and behold i've got this little blue wire from my bat+ going to a flimsy little crimp to an 8ga or so white wire running to the fuse box.
I didnt bother taking apart the fuse assembly as my hands where literally covered in black goop from pulling off the casing covering the blue wire. Seriously, wear gloves when investigating any of this. There is still some on my hands after numerous gojo washes. Anyway, I chose to cut the blue wire clean off of the white cable and solder 10ga wire to a new ring and connect to my batt.
Result:
Truck has more pep all the way around. This has affected everything within the fuse box - my windows now roll up and down faster, truck is instantly more responsive, and best of all, I no longer have low idle issue.
I'll update this if anything should change in relation.
I came across this post in the "Show us your best cheap mods section" and decided to investigate. Well; low and behold i've got this little blue wire from my bat+ going to a flimsy little crimp to an 8ga or so white wire running to the fuse box.
I didnt bother taking apart the fuse assembly as my hands where literally covered in black goop from pulling off the casing covering the blue wire. Seriously, wear gloves when investigating any of this. There is still some on my hands after numerous gojo washes. Anyway, I chose to cut the blue wire clean off of the white cable and solder 10ga wire to a new ring and connect to my batt.
Result:
Truck has more pep all the way around. This has affected everything within the fuse box - my windows now roll up and down faster, truck is instantly more responsive, and best of all, I no longer have low idle issue.
I'll update this if anything should change in relation.
06-10-2011, 09:12 AM
#75
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Thanks for the write-up. I just replaced the factory fusebox feed with 4ga battery cable. My 95 did not have an inline fuseable link as some of use have described. I took another section of 4ga wire and ran a new ground to the pass side fender. It looks like a previous owner had messed with this truck before as the ground was 2 8ga wires grounded to the fender then twisted into the neg battery cable.
Unfortunately it appears that my alternator is still not generating enough amperage at idle to run the accessories. Does anyone know if there is a high output version available for these trucks or what the stock unit even puts out?
I plan to replace the alternator with a beefier unit and run a wire direct to the battery since I have an electric fan and sub in the truck.
Unfortunately it appears that my alternator is still not generating enough amperage at idle to run the accessories. Does anyone know if there is a high output version available for these trucks or what the stock unit even puts out?
I plan to replace the alternator with a beefier unit and run a wire direct to the battery since I have an electric fan and sub in the truck.
06-10-2011, 09:18 AM
#76
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https://www.yotatech.com/forums/f116...-issue-222715/
One option:
Boyle Future Technology
12325 Locksley Lane
Auburn, CA 95602
Phone: 530-888-6290
Another option:
170 amp (75 at 1000 rpm, 170 @ 1800 rpm) alternator from AlterStart, comes with a 1 year warranty for $199
[FONT=Comic Sans MS][SIZE=2][COLOR=DeepSkyBlue][COLOR=DeepSkyBlue]
Last edited by TNRabbit; 06-10-2011 at 09:19 AM.
04-20-2012, 05:33 PM
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Hell yea this forum helped me with my 3.slow 94 well not the most I thought it would but I used a copper terminal wasn't quite sure how to solder copper so I jus crimped it and it worked out pretty Dan good voltage meter still drops jus a tad but not as much thanks...
07-23-2013, 04:10 PM
#79
Registered User
Okay, I've been doing some research on this as I plan to move forward.
From what I can gather, here's what I know:
***Do Not Remove the Blue Wire in original instructions as it is a fusible link that prevents you from toasting line(s) further up your electrical system. This is the one big difference from the original project. That said, it can be overcome.
In a previous post, GoBlue notes that fusible link is blue, 16 gauge wire.
https://www.yotatech.com/forums/f116...l#post51478614
Fusible links are typically 4 sizes smaller than stock wiring.
Can anyone confirm the gauge and/or Toyota's fusible link colors? I found the following info here: http://www.stangnet.com/mustang-foru...erages.819889/
Rather than the potentially restricting and hard to fix fused link, I am going to go with either a Maxi Fuse or ANL instead (leaning towards ANL as most Maxi Fuse holders I've seen max at 8 AWG wiring into them if protected, or you have not protected but able to connect ring terminals...), and will probably go with a Blue Sea Systems product. But I need to know the needed Amp rating first.
Looking at the electrical diagram: http://personal.utulsa.edu/~nathan-b.../2powersou.pdf
It looks like there are 4 fusible links further down line -- 2 30As, 1 80A, and 1 40A. Carrying an 80A load would suggest/require a 12 gauge link from battery with 8 gauge wiring...
And related, I'm going to go with this crimping tool to make the job much easier: http://www.ebay.com/itm/TEMCo-LUG-CR...-/400441203422
From what I can gather, here's what I know:
***Do Not Remove the Blue Wire in original instructions as it is a fusible link that prevents you from toasting line(s) further up your electrical system. This is the one big difference from the original project. That said, it can be overcome.
In a previous post, GoBlue notes that fusible link is blue, 16 gauge wire.
https://www.yotatech.com/forums/f116...l#post51478614
Fusible links are typically 4 sizes smaller than stock wiring.
Can anyone confirm the gauge and/or Toyota's fusible link colors? I found the following info here: http://www.stangnet.com/mustang-foru...erages.819889/
Wire size current table (main, existing wiring):
18 gauge wire = 5-8 amps
16 gauge wire = 10-12 amps
14 gauge wire = 15-17 amps
12 gauge wire = 20-25 amps
10 gauge wire = 30-40 amps
8 gauge wire = 50-60 amps.
Fusible link colors
Link Gauge Color
20 Gauge Blue
18 Gauge Brown or Red
16 Gauge Black or Orange
14 Gauge Green
12 Gauge Gray
This site has a chart that's handy too: http://minimopar.net/electrical-links.html (note it's not for our Yotas but handy point of reference nonetheless): 18 gauge wire = 5-8 amps
16 gauge wire = 10-12 amps
14 gauge wire = 15-17 amps
12 gauge wire = 20-25 amps
10 gauge wire = 30-40 amps
8 gauge wire = 50-60 amps.
Fusible link colors
Link Gauge Color
20 Gauge Blue
18 Gauge Brown or Red
16 Gauge Black or Orange
14 Gauge Green
12 Gauge Gray
Circuit - Hypalon Link Type - MAXI Fuse Rating - Circuit Wire
Alternator Feed (R6) - 12 gauge (black) - 160 amp (2x80 in parallel) - 8 gauge (BK)
Radiator Fan (C26) - 20 gauge (orange) - 40 amp - 14 gauge (GY)
Ignition Feed (J10) - 18 gauge (grey) - 50 amp - 12 gauge (PK/BK*)
Ignition Feed (J1) - 20 gauge (orange) - 40 amp - 12 gauge (RD)
ECU/ASD Feed (J1) - 22 gauge (white) - 30 amp - 12 gauge (PK)
Direct Battery Feed (L1) - 18 gauge (grey) - 50 amp - 12 gauge (RD/WT*)
Heated Rear Window (C13) - 18 gauge (grey) - 40 amp - 12 gauge (BK/RD*)
Hazard Flasher (A3) - 20 gauge (orange) - 20 amp - 14 gauge (PK)
So the color and size of GoBlue's post doesn't seem to match up, so one is wrong unless Toyota has their own colors for fused links. It would be 20 gauge protecting 16 gauge based on color, or 16 gauge protecting 12 based on size. The 16 gauge main wiring would be able to handle a current of 10-12 amps, or the 12 gauge main wiring would be able to handle a current of 20-25 amps. So we need to know the gauge prior to fixing... Or also likely, it's a 12 gauge link protecting 8 gauge wiring... Anyone know for certain?Alternator Feed (R6) - 12 gauge (black) - 160 amp (2x80 in parallel) - 8 gauge (BK)
Radiator Fan (C26) - 20 gauge (orange) - 40 amp - 14 gauge (GY)
Ignition Feed (J10) - 18 gauge (grey) - 50 amp - 12 gauge (PK/BK*)
Ignition Feed (J1) - 20 gauge (orange) - 40 amp - 12 gauge (RD)
ECU/ASD Feed (J1) - 22 gauge (white) - 30 amp - 12 gauge (PK)
Direct Battery Feed (L1) - 18 gauge (grey) - 50 amp - 12 gauge (RD/WT*)
Heated Rear Window (C13) - 18 gauge (grey) - 40 amp - 12 gauge (BK/RD*)
Hazard Flasher (A3) - 20 gauge (orange) - 20 amp - 14 gauge (PK)
Rather than the potentially restricting and hard to fix fused link, I am going to go with either a Maxi Fuse or ANL instead (leaning towards ANL as most Maxi Fuse holders I've seen max at 8 AWG wiring into them if protected, or you have not protected but able to connect ring terminals...), and will probably go with a Blue Sea Systems product. But I need to know the needed Amp rating first.
Looking at the electrical diagram: http://personal.utulsa.edu/~nathan-b.../2powersou.pdf
It looks like there are 4 fusible links further down line -- 2 30As, 1 80A, and 1 40A. Carrying an 80A load would suggest/require a 12 gauge link from battery with 8 gauge wiring...
And related, I'm going to go with this crimping tool to make the job much easier: http://www.ebay.com/itm/TEMCo-LUG-CR...-/400441203422
Last edited by RSR; 07-23-2013 at 04:21 PM.
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