94 Shift Lock Issues

[Mstudt]

I've been through previous threads, and consulted my EWD book. Per the EWD and as shown below in pictures.

Based on the readings below, I think it eliminates the stop switch since I have 11.86 volts at pin 6 when the brake pedal is depressed. I can also confirm that all brake lights work as they should, and that all 3 fuses (CIG, ECU, STOP) are good. It look like the power on pin 3 might be my issue, but I'm still up in the air about the potential issue. I did check for voltage at the ECU fuse location, and there's voltage on both sides of the fuse. It looks like the ECU fuse feeds the shift lock and transmission control module.

I should also add the I removed the trailer harness from the rear since it was a hack job, and replace the entire harness across the back with a good hardness.

1-Ground (approx 12v with IG SW at ON) - pulling 11.69 volts (looks good)
3-Ground (approx 12v with IG SW at ON) - pulling .58 volts (looks NOT good)
5-Ground (Continuity) - pulling .4 ohms (looks good)
6-Ground (approx 12v when brake pedal depressed) - pulling 11.86 volts (looks good)

 

[LandLocked93]

Just a hunch, after looking at the shift lock schematic and fuse schematics, which ECU fuse did you check?
There are a couple.

 

[Mstudt]

Just a hunch, after looking at the shift lock schematic and fuse schematics, which ECU fuse did you check?
There are a couple.

The 15 amp ECU IG fuse.

Mike

 

[Mstudt]

I ruled out the Key Interlock Solenoid as well. Pin 4 is pulling 0 volts while in P (acc position), and 11.60 volts when in reverse. So the only pin that doesn't look correct is still pin 3 from the ECU IG. I did notice when putting the fuse back in for the ECU IG there were a couple clicks from either under the dash or under the hood near the firewall.

Mike

 

[jonheld]

I ruled out the Key Interlock Solenoid as well. Pin 4 is pulling 0 volts while in P (acc position), and 11.60 volts when in reverse. So the only pin that doesn't look correct is still pin 3 from the ECU IG. I did notice when putting the fuse back in for the ECU IG there were a couple clicks from either under the dash or under the hood near the firewall.

Mike

Have you checked pin 13 of ID2 in the left kick panel??

 

[Mstudt]

Have you checked pin 13 of ID2 in the left kick panel??

View attachment 3595861

View attachment 3595863

I hadn't got that far, but it's next on my list. When it comes to pin 13, what am I looking for?

Mike

 

[jonheld]

I hadn't got that far, but it's next on my list. When it comes to pin 13, what am I looking for?

You stated that you're not getting +12 to pin 3 of the shift lock ECU, but you're getting +12 to the ECU-IG fuse. So either the fuse is faulty or there is no connection between the ECU-IG fuse and pin 3 of the shift lock ECU.
I would be checking continuity between the load side of the fuse and pin 3 of the shift lock ECU which goes through pin 13 of connector ID2.

 

[Mstudt]

You stated that you're not getting +12 to pin 3 of the shift lock ECU, but you're getting +12 to the ECU-IG fuse. So either the fuse is faulty or there is no connection between the ECU-IG fuse and pin 3 of the shift lock ECU.
I would be checking continuity between the load side of the fuse and pin 3 of the shift lock ECU which goes through pin 13 of connector ID2.

Correct, I'm not getting 12v to pin 3 on the vehicle harness side. I replaced the ECU IG fuse before doing the test just to be on the safe side. I'll check for continuity between pin 13 on the ID2 and pin 3 for the shift lock ECU.

Mike

 

[Mstudt]

You stated that you're not getting +12 to pin 3 of the shift lock ECU, but you're getting +12 to the ECU-IG fuse. So either the fuse is faulty or there is no connection between the ECU-IG fuse and pin 3 of the shift lock ECU.
I would be checking continuity between the load side of the fuse and pin 3 of the shift lock ECU which goes through pin 13 of connector ID2.

I'm pretty sure that I have the correct plug and pin location shown below. The color of the wire does match from pin to pin as well. I checked with 2 different meters just to make sure.

 

[jonheld]

I'm pretty sure that I have the correct plug and pin location shown below. The color of the wire does match from pin to pin as well. I checked with 2 different meters just to make sure.

Are you asking a question?

 

[Mstudt]

Are you asking a question?

Just a stating that I'm pretty sure that was the plug considering the wire colors matched.

Anyways, I think you pinpointed the issue being the wire. Any idea why or how this could have happened? I'm not sure if this could have been related to the leaking windshield gasket. It was leaking when I got it, and not sure how long it was leaking prior to that.

Mike

 

[jonheld]

Just a stating that I'm pretty sure that was the plug considering the wire colors matched.

Anyways, I think you pinpointed the issue being the wire. Any idea why or how this could have happened? I'm not sure if this could have been related to the leaking windshield gasket. It was leaking when I got it, and not sure how long it was leaking prior to that.

Mike

If the water caused any sort of corrosion, then that's your issue. That plug is in a prime location to get hit by windshield leaks.

 

[Mstudt]

If the water caused any sort of corrosion, then that's your issue. That plug is in a prime location to get hit by windshield leaks.

Makes perfect sense since some of the pins due have a sight blueish corrosion look to them. I think I'll clean the plugs while its apart, and while I'm waiting on new crimp terminals.

Thank you for the help too!

Mike

 

[CharlieS]

I've had good luck with a product called Deoxit.

 

[Mstudt]

Got some parts in today so I could make a new section of wire. After 20 minutes of work I can confirm that my sift lock is now working again. With this issue being something in the wire harness. I'm now pretty sure that my locker issue is also tied to this harness.

Thanks for all the help!

Mike