osv

did you try swapping out the relay board itself?

does the engine running make any difference in how the window works? because there is more current available when the engine is running... it makes a noticeable difference in how fast my rear window goes up and down.

the symptoms on my first-gen were different than yours, but i ended up removing a couple of the relays, and hard-wiring a switch in there... no rear access with key, of course.

the relays might be clicking with the 9v battery, but that doesn't mean that they are capable of carrying enough current to support operation of the rear window.

naparacing

No id did not try swapping the whole board because the donor rig is a 89 and mine is a late model 91. I think it has a 92 and later board in it. considerably smaller and two extra relays and different socket. But like is said by energizing them with just a common 9 volt battery they all fire and switch continuity from on leg to the other. I think I can reasonably rule out the relay board. They will not even click when it is installed in the rig. I know which two relays fire with the inside switch but not sure between the remaining four that control the rear key switch and the rear defroster. I have a new high crank battery in it so there is not noticeable difference when it is running or not with the inside switch.

osv

it is interesting that you don't hear the relays clicking, when actuated by the rear switch... if they clicked and the window didn't move, it would be easier to fix, i think.

the key switch being turned is going to probably short out a path somewhere, which you can check with an ohmmeter, but you'll need the factory wiring schematic, and probably someone to turn the key while you monitor the circuit board area.

if i recall correctly, there are fail-safes in there, like that rear wiper, that prevent the window from working... but we know that it's not the rear wiper circuit, because everything works from the inside switch.

gotta look at a schematic... in theory, you could short the circuit board contacts across, at the terminals where the rear key switch wiring hit the circuit board.

naparacing

I totally agree. My thoughts are at this point there are three wires coming off that rear key switch. One of them is white and I think it is the common wire and the other two are up and down. Since it does not click or move in either direction I am going to try to trace that white wire through the harness where it leaves the tailgate and heads up into the body to the relay board. My only other option, unless there is a switch that I am missing somewhere in the circuit.

Aaron Mitchell

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