Hey guys I'm losing my mind over here trying to chase down an electrical demon. I feel like I'm chasing my tail here. Strap in this going to be a long one.

I have a 1997 with a EBCM that reads NO COMM. It has power and ground going to the module. So I'm sure the module is DOA. Until a week ago I had a RTD that read NO COMM as well. I picked up a used F45 module and Ebay and that too care of that. The RTD came back with no codes on the DIC.

Fast forward to this weekend. I spent the majority of the day yesterday installing new front speakers. When I went to start the car to move it the DIC went crazy. It was stuck in an endless loop of service engine and service ride control. It would not let me access a single thing on the DIC. It was as if the buttons were not registering. So I figured either I scored a wire with a screw installing the speakers or I have an issue in the door boots. Well the pass door wiring looked fine but the uninsulated wire in the driver boot was questionable. I repaired that and the DIC now allowed me to check codes. The RTD came back with 1780 for the steering wheel position sensor. I thought that was odd since I've never had that code come up in the past. When I would clear that code the RTD would come back again with NO COMM. I started the car a few times to verify my findings. Everything stayed the same. After going through all the wiring and being satisfied with the condition I reinstalled the door panels. Sure enough as soon as I go to back the car into the garage the DIC wigs out again.
As of right now I can not check the codes until I can get the DIC to start acting right. Any suggestions on where to start?

 

Is the battery is fully charged?

 

Yes. I forgot to mention that. The car has been on a tender all winter. In fact the battery was purchased new in the fall last year.

 

That doesn't mean it's good. Have you checked it with a meter or had it load tested.

 

Not load tested but the meter reads 12.5v.

 

Is there a way to narrow down where the possible break in the wire is? Is it possible the new to me f45 module is the issue? When I first put it in I only started the car a couple times. I never drove it. Moving the car this weekend is the first time the car moved with that new computer.

 

This will sound silly but,,,, Open BOTH DOORS,, Grab the rubber accordion tube that goes between the door and the body. Pinch the rubber tube and feel for the wiring harness inside. While pinching the harness inside the tube, SHAKE that rubber accordion tube very hard several times.

Go back and see if it resolve the weird DIC and NO COMMS issues.

Bill

 

At this point Bill nothing sounds silly. I had both wire looms pulled from the door boots and that when I discovered the questionable uninsulated wire in the driver side boot. Since it was breaking at the pin I wired a jumper wire around the plug. I will certainly try the squeeze the boot tactic either tonight or tomorrow since its raining today.

 

This was picture I took from Sunday when I was trying to diagnose the issue

 

Here is a shot of the driver side with the temporary jumper in place. I apologize for the filthy door sill. It's been in storage for a few years. The deep clean comes after its road worthy. But in all honesty it looks pretty good for 185,000 + miles.

 

If I were to disconnect both sides at the door boots would that help to diagnose the issue? In theory it would eliminate both doors from being the problem and I could start looking at other possible causes. Like the key cylinder for instance.

 

Time for an update. Today I was able to jump back on this but I really didn't make any progress. First I opened up the doors and squeezed/shook the accordion boots to no avail. I then disconnected the harnesses in the boots one by one side by side. First the pass side then the driver side checking the ignition each time. No change. I then started poking around the bcm to see if any of the wires looked broken or chafed. Once again nothing looked out of the ordinary.

I read on here if the contacts in the ignition switch were corroded it could cause some very strange problems. Using the repair procedure found on here by Bill Curlee I discovered the contacts were in terrible shape. 3 of the contacts were solid black. I cleaned them and retensioned the springs. Well when I plugged it I to the car it still was acting funny but it wasn't as bad at first. Then it went back to not responding to the buttons and randomly switching through the menu.

So where do I go now??