Something of an update. I had a suspicion. In the past whenever the radio would go out I would pull the fuse and replace it but when doing that the ICP would react.
I tried plugging in the radio fuse and everything started to work again. Is this a problem?

 

Which radio fuse is doing this, there are more than one.


George

 

It's a 15a RDO BATT Fuse.

 

OK, that fuse powers the radio and is also the main power for the IPC so it does not surprise me that the IPC wakes up when that fuse is inserted. What does surprise me is that “everything started working again”. Do you mean that every illumination bulb that has been out has come on including the bulbs in say the door switches? What is the voltage measurement now at the Illumination fuse where you had 0v before? There are three different categories of illumination bulbs and they all get powered from different circuits so waking up the radio and IPC should not effect all of them like this.


George

 

I can't really tell if the door lights are cutting on but everything I can see is dimming with the headlamp switch now.

For the ILLUM Fuse, I'm getting these readings.
[With the car running]
- Headlamp switch in 1st position, dimmer up: 0
- Headlamp switch in 2nd position, dimmer up: 12.10 volts
- Headlamp switch in 3rd position, dimmer up: 12.03 volts

[Just in case]
- Headlamp switch in 1st position, dimmer down: 0 volts
- Headlamp switch in 2nd position, dimmer down: 0.09 volts
- Headlamp switch in 3rd position, dimmer down: 0.10 volts

What it was before I put the RDIO fuse in, I was getting backlights, battery voltage, and the check engine light on the ICP, just no readings like the gas, mph, [PRN321], and stuff like that.
For now it seems to be fixed, but one random day it'll start acting up out of nowhere and the power will cut out like there's a shortage.

 

I don’t know why the RDO batt fuse fixes your illumination dimmer situation. Per the schematic and the description in the service manual that should not be the case but some of the pins that are connected on that illumination circuit do not have clear labels. Glad you’re fixed up for now.

George

 

I'll keep everything unassembled for right now. If it happens again I won't have to undo everything again. I'll drive it around a bit today and see what happens.