Temp and Fuel Gauge all bouncy..
 

I did a pod refresh, new bulbs, new foil..cleaned the connection ends all studs and nuts..everything..and I still have these two gauges that just don't work right.

Pod's gotta come out again, but what should I be looking at this time?? Nothing could possibly be cleaner...I wouldn't think...

https://cimg4.ibsrv.net/gimg/rennlis...bacfeb9e2.jpeg
https://cimg5.ibsrv.net/gimg/rennlis...bc27cc985.jpeg
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If it wasn't like that before you worked on it, that probably eliminates the gauges and points to a connection issue.
Both of those gauges come through "plug A"...that would be where I would check, first.
Sometimes a reach behind and a wiggle on the connector will cure things.

I had an issue with my fuel gauge where the wire from the sender under the pod was a bit corroded. A wiggle fixed it as suggested above.

Couldn't hurt to hit the pins with some deoxit and a q tip.

I would suggest to put the D 100 on the connectors only ,
spraying the foil with the D 100 can cause the metal tabs to de laminate . BTDT

These were why went in there in the first place...but remained funky.

Foil stayed dry, was no need, only the connectors and then cleaned of residue.

I had a similar issue on my 951. Noticed that the gauge (temp/fuel) were only bouncy when I turned the lights on. Cleaned battery grounds and checked brown wires. Not sure which random ground cleaning cured it, but that was it.

Remove the stacked ground wires down by the pedals and clean them and the point where they attach.. Clean the main alternator ground. That oscillation in the needles is sometimes from the rotation of the alternator.

100% they curl up and give you the copper middle finger of death

If multiple gauges are affected in the same way at the same time its a grounding issue - focus there .

Alan

I'm not going to say that it isn't a good idea to clean all of the main grounding points, however I kinda doubt that removing the cluster and working on it is going to suddenly cause a connection issue at a remote bolt though grounding point.
.....Definitely not where I'm going to tell one of my guys to go, first.
Now if the problem existed before removal....that's a whole different story.

Just those two, were like that before and after.

I cant believe I didnt touch the ground point back there...

I'm not talking about all the ground points or even just the chassis ground points. This IS clearly a grounding issue from the symptoms - I'm not just guessing. Look at the chassis grounds specifically for the pod and also all the ground connections inside the cluster to the gauges. It must be a common point to all the gauges affected. As Greg says it is most likely something you touched - quite possibly internal to the cluster. On re-reading it seems you've had this a while - however its still a local issue to the pod grounds.

Alan

Well..like I said it was there BEFORE as well, nothing I touched started it. I was doing the foil and cleaning EVERYTHING (except that damn ground point back there) in the process.

Yup..we're on the same page.

Which plug is "A"?

Allen, just where are the pod grounds located? Just asking for future refs.

MP/GP IV is on the steering console behind the cluster (easiest to reach with pod & cluster out) and that's the main one for the cluster - There is also a ground connection distribution point - it connects to MP IV and also to cluster plugs: A, B & C (Brown wires) as well as other places- check that one for good connections - you should be able to follow the brown wires to find it.

Alan

Thanks Alan. The pod is out. what is MP/GP IV ?

https://rennlist.com/forums/928-foru...-on-an-s4.html

Jeff:

I've experienced issues with the gauges reading incorrectly because of resistance in those grounds on my 88. I pulled the pod and cleaned the posts that power the volts, fuel, oil pressure, coolant terms. And that really helped the issues I was having with the fuel gauge (not reading full) and volts reading lower than what was measured at the CE panel.

Not exactly the bouncing issue you describe, but it could help
https://benno928.files.wordpress.com...s-2.jpg?w=1000https://benno928.files.wordpress.com...s-2.jpg?w=1000https://cimg1.ibsrv.net/gimg/rennlis...5dc1e88400.png

Plug A is the one with the Blue/Yellow, Grey/Green & Violet/Black wires

Alan

Pretend I cant see.

L/R?

I'm pretending you can't see... but I still don't know! - my experience is mainly with Digi-Dash cars ~2 generations removed. We need someone with an OB dash apart to help out here.
To investigate all the connections I think it may need to come out again anyway :(. The good news is it gets quicker & easier every time you do it - the bad news is it gets old over & over too.

Alan

Well, I can't see, hear or read, but plug A would be the one on your left, looking at the cluster from your seat. i think ;-)

i HAD SAME ISSUE WITH TEMP gauge affected by turning lights on - ground issue. The blades in the connector hoods are quite soft, and it seems the act of touching them with a meter probe was enough to bend them - advice from here. I cleaned the blades, applied Deoxit, and retensioned them with a small right-angle probe (dental pick?), problem solved. IIRC there are 3 ground connectors in the right hand connector hood.
jp 83 Euro S AT 57k