So a new thing has recently reared its head on my red 85. The "I" light in the cluster center never fully goes out after I release the e-brake. Instead, it just dims way down. You can't really notice it in daytime driving, but it is very obvious in the parking garage or the garage at home, or at night.

One other data point, as long as I've owned the car, when I put the headlights on, I get a full brightness "I" light and a tail light warning on the cluster. No tail lights are out. I push the "I" light button on the consol, and the "I" light on the cluster always went all the way off, until recently (now it's a ghost light).

Thoughts?

 

Voltage back feeding due to bad ground?

 

I have the same on my 86'..... I posted about this a few years back. I found no solution.

 

Like this:

https://rennlist.com/forums/928-foru...ght-issue.html

 

Yes, that’s exactly my problem too. I will pull the CE panel this weekend and do a full service on it plus clean the grounds there. I already did the pod and cluster and combo switch a few months ago. This problem just came up though, and the last thing I did was swap out some relays in correcting a fog light issue.

 

Let me preface this post with the disclaimer that I always feel like like my advice should come with a grain of salt and definite oversight from the professionals that know better and have more depth of knowledge on this board.

I have experienced the same thing you describe. On my 85, I started to get the random "tail light" error, I would check (and re-check), but everything would run normal. I was also getting the ghost "!" illumination where it wouldn't be "on", but was there as a faded shimmer . This would come and go randomly until one day I noticed my battery/alternator gauge was reading just a tad lower, almost unnoticeable.

I pulled my battery; noted that it was aging, and bought a new one (just because). I took apart all connections on the positive side terminal and cleaned the crap out of all ends. My ground side strap was already fairly new, so no worries there.

I put the new battery in with sparkling clean battery connections (all battery compartment connections, not just the terminal ends) on both sides of the battery, The gauge started reading normal again.

Coincidentally, The ghost tail light error and the "!" shadow never returned.
At least, (knock on wood), they haven't yet, and that was many months ago.

Again, disclaimer: I am not an expert and this may not be your problem, but it is what worked for me.

 

The only thing more mysterious and unfathomable than the 928's electrical system is a woman's emotions.

 

That is good stuff. So this weekend when I do the CE panel and all ground points down there, I'll also go to the hatch with my brush and cleaner.

 

NOTE disconnect the battery before performing these tasks..

Ed I would also suggest that you lift the front E brake cover and clean / D100 and tighten the E brake switch.
In the hatch take apart and D100 both side marker connectors these are flat white 2 pin connectors near the rear edges of the quarter liners .
(these could also be behind the liners)

In the RR quarter of the hatch behind the liner,
remove the floor hold down clamp first, (so you can bend the liner)
spray D100 on the ground point and tighten the bolt.

Clean the battery leads and every wire attached to it.

Above the CE panel remove both ground bolts and clean and D100 the wires.
do the same for the 3 red wires bolted to the top of the CE panel.

replace the instruments fuse with a new one and D100 to every elex connection that you touch.
clean the ground under the pod thats attached to the steering column.

 

Good stuff. That’s the plan

 

Cheers Stan, I will try this route as well.

 

Stan, isn't D5 a better cleaner spray than the D100 as it has a chemical combined with the 5% solution to cleans and remove corrosion before protecting it? I thought the D100 was preferred for contacts that were already clean.

 

I would say there is no need to use the two versions of "928 Holy Water" in succession.

https://caig.com/wp-content/uploads/...h-info-new.pdf

 

PETE just use the D100 unless your connector is soaked in oil or some other contaminant.
I usually use a red 3M pad to abrade the contacts then the D100 for final assembly.

The full strength fluid will remove the corrosion it can take up to 24 hours for this to work.
The D 5 is more of a flushing spray,that leaves small amounts of the fluid behind.

 

Thanks Stan. Off to Amazon I go.