1990 toyota pickup charge issues
02-05-2021, 12:43 PM
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1990 toyota pickup charge issues
Hello, I have a 1990 Toyota pickup Xtra cab 4x4 3.0l v6. I am having an issue with the charging system and I can't find a solution anywhere. When I start the truck up, I get the dash light code for charge issues (E-Brake and Battery) but the voltmeter in the cab reads that the battery is receiving the proper charge. While this happens the daytime lights don't turn on. Occasionally when I am driving, the daytime lights will kick on and the codes will disappear. When this happens the voltmeter drops significantly and slowly goes down as if the charging system is bad. All I have to do to correct this pullover and turn the truck off and on again. I can sometimes drive for 100 km or it will happen in as little as one.
Thanks
(Put a new alternator in her about a year ago as well)
Thanks
(Put a new alternator in her about a year ago as well)
02-05-2021, 03:42 PM
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Welcome to YotaTech.
I'm not as familiar with trucks from the Great White North, but I would start by verifying that your brake fluid level switch does what you'd expect. http://web.archive.org/web/201203161.../4mastercy.pdf (Mine doesn't look like the one in this 1993 manual, but they all have a float that operates a switch. You should be able to move the float to get the brake light to change.) I'd also use a "real" multimeter to check the charging voltage on the battery (should be 14.1-15.1v). The combination meter gauges are not known to be lab-accurate.
The "Alt" light connects to pin 1 of the 3-terminal plug on the alternator. The wire should be yellow ("engine" is red, "sense" is white). That wire should be held to ground when the alternator is not producing power, alternator voltage (14.1-15.1v) when the alternator is running. I understand that DRL do not turn on until the alternator is producing power, meaning there is alternator voltage on the yellow wire.
It does sound like you've got an intermittent connection somewhere, which will make it all the harder to find. Be systematic, and let us know what you find.
I'm not as familiar with trucks from the Great White North, but I would start by verifying that your brake fluid level switch does what you'd expect. http://web.archive.org/web/201203161.../4mastercy.pdf (Mine doesn't look like the one in this 1993 manual, but they all have a float that operates a switch. You should be able to move the float to get the brake light to change.) I'd also use a "real" multimeter to check the charging voltage on the battery (should be 14.1-15.1v). The combination meter gauges are not known to be lab-accurate.
The "Alt" light connects to pin 1 of the 3-terminal plug on the alternator. The wire should be yellow ("engine" is red, "sense" is white). That wire should be held to ground when the alternator is not producing power, alternator voltage (14.1-15.1v) when the alternator is running. I understand that DRL do not turn on until the alternator is producing power, meaning there is alternator voltage on the yellow wire.
It does sound like you've got an intermittent connection somewhere, which will make it all the harder to find. Be systematic, and let us know what you find.
02-06-2021, 12:49 AM
#3
How charging system works : https://www.yotatech.com/forums/f116...s-22re-304868/
Check voltages at points on post ^^^
Should be same as your truck's.
Check voltages at points on post ^^^
Should be same as your truck's.
02-07-2021, 12:58 PM
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Welcome to YotaTech.
I'm not as familiar with trucks from the Great White North, but I would start by verifying that your brake fluid level switch does what you'd expect. http://web.archive.org/web/201203161.../4mastercy.pdf (Mine doesn't look like the one in this 1993 manual, but they all have a float that operates a switch. You should be able to move the float to get the brake light to change.) I'd also use a "real" multimeter to check the charging voltage on the battery (should be 14.1-15.1v). The combination meter gauges are not known to be lab-accurate.
The "Alt" light connects to pin 1 of the 3-terminal plug on the alternator. The wire should be yellow ("engine" is red, "sense" is white). That wire should be held to ground when the alternator is not producing power, alternator voltage (14.1-15.1v) when the alternator is running. I understand that DRL do not turn on until the alternator is producing power, meaning there is alternator voltage on the yellow wire.
It does sound like you've got an intermittent connection somewhere, which will make it all the harder to find. Be systematic, and let us know what you find.
I'm not as familiar with trucks from the Great White North, but I would start by verifying that your brake fluid level switch does what you'd expect. http://web.archive.org/web/201203161.../4mastercy.pdf (Mine doesn't look like the one in this 1993 manual, but they all have a float that operates a switch. You should be able to move the float to get the brake light to change.) I'd also use a "real" multimeter to check the charging voltage on the battery (should be 14.1-15.1v). The combination meter gauges are not known to be lab-accurate.
The "Alt" light connects to pin 1 of the 3-terminal plug on the alternator. The wire should be yellow ("engine" is red, "sense" is white). That wire should be held to ground when the alternator is not producing power, alternator voltage (14.1-15.1v) when the alternator is running. I understand that DRL do not turn on until the alternator is producing power, meaning there is alternator voltage on the yellow wire.
It does sound like you've got an intermittent connection somewhere, which will make it all the harder to find. Be systematic, and let us know what you find.
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