I have a 87 GN and the cruise and TCC lock up quite working recently. I was thinking it would be the brake light switch since both items disengage when the brake pedal is depressed but the brake lights seem to work ok. I checked the votlage from Pin F ALDL(ECM A7) and there is no 12 volts there with the key on/engine off so the 12 volts is being shorted somewhere. Does anyone have a suggestion on where to look for the problem?
NO cruise or TCC lock up and 12 volts not present at ALDL Pin F, where should I look?
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salvageV6
Daily Driver
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- May 25, 2001
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ECM/SOL fuse 10A upper right hand corner of the fuse box.
Thanks for the quick response guys! I checked the ECM/SOL fuse and its good. I played around with the brake light switch and it seems to be OK but I could be missing something with the adjustment. I pushed the brake pedal down and used my finger to push the plunger in as far as possible and the brake lights go on and off as they should but I never was able to get the 12 volts at Pin F to come on in any position of the switch, am I missing something? Thanks!
salvageV6
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At the brake switch make sure the pink/blk wire is +12 with the key in the Run position.
It's terminal B, the output of the switch is the purple wire so when it's adjusted properly the purple wire will read +12 when the brake switch is NOT Pressed down.
After that it goes to terminal A on the TCC transmission plug and is a tan/blk wire there and also at the ALDL port.
It will only read +12 if the ECM IS NOT commanding lockutp or shorted somewhere like if the TCC lockup switch most people add to their cars is left ON, make sure that switch is OFF.
And you won't read +12 at the ALDL port unless the TCC solenoid is good and the tranny wiring plug on the side is connected up properly.
It's terminal B, the output of the switch is the purple wire so when it's adjusted properly the purple wire will read +12 when the brake switch is NOT Pressed down.
After that it goes to terminal A on the TCC transmission plug and is a tan/blk wire there and also at the ALDL port.
It will only read +12 if the ECM IS NOT commanding lockutp or shorted somewhere like if the TCC lockup switch most people add to their cars is left ON, make sure that switch is OFF.
And you won't read +12 at the ALDL port unless the TCC solenoid is good and the tranny wiring plug on the side is connected up properly.
salvageV6
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The cruise is on it's own 5A fuse.
However, there's a vacuum switch and an electrical switch at the brake pedal that shut it off and will keep it from working.
The electrical switch has a gray wire on Pin A which is +12 with key on and cruise switch ON, and the output of that brake switch is a brown wire which has +12 on it with the above conditions UNTIL the brake pedal is pushed then it breaks that circuit.
Most likely the issue is at the brake switches.
However, there's a vacuum switch and an electrical switch at the brake pedal that shut it off and will keep it from working.
The electrical switch has a gray wire on Pin A which is +12 with key on and cruise switch ON, and the output of that brake switch is a brown wire which has +12 on it with the above conditions UNTIL the brake pedal is pushed then it breaks that circuit.
Most likely the issue is at the brake switches.
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