Since purchasing my 928 (78, 5-speed, 90,000+ miles) a couple weeks ago I've had an intermittently working odometer and odd electrical problem. The odometer turns once in a while, seemingly at random. Since the gear seems to be a common issue I ordered one from rennbay and replaced it Saturday night. The electrical gremlin I'm also hunting is that sometimes, also at random but not tied to the odometer function, all the 'idiot' lights in the pod and central warning panel below the AC all light up and stay on until the car is restarted.

While I had the pod off I cleaned all the film contacts with an eraser and hit all contacts with contact cleaner. Once the pod was removed I found nothing wrong with the original gear but replaced it anyway. When I got things reassembled, I still had a non-working odometer and the odd warning light issue.

I'm wondering what my next step would be for both of these? Can I test the small electric motor that drives the odometer using a 9v battery or something similar to make sure it's turning? I've also noticed that in the post about cleaning all the grounds one is mentioned being near the steering wheel. My pod has a screw screwed into the sheet metal but there was no wire connected to it, should this be a ground point?

My last question (that may or may not be related) is about a new looking 40 amp fuse I found connected under the pod. The wires connected to it look factory, but I really have no way of judging. Based on the wire colors (pic below), any idea what the heck this could be doing in there or should I just pull it and see what no longer works?



I also managed to rekey my drivers door and hatch today so that now I'm down to only needing one key for everything instead of three!

Thanks in advance for any and all help!

-Stephen

 

Is that the dash rheostat wires? I may be wrong though.

 

Also I had to change my gauge circuit board to fix my speedo problem along with the gear.

 

The fuse replaces the instrument light rheostat, it isn't required - you can just join those wires there is already a fuse (much less than that 40A!)

Alan

 

No, not the rheostat. This is in the bundle of wires to the left side of the steering column with the headlight and fog light switches as well as the odometer reset button. One added benefit of doing this was that my rheostat is now connected as the wires for it and the small button next to it were just hanging loose when I bought it.

 

My wires are soldered together by a PO.

 

Intense wash maybe? I know I've seen those blue wires before on my pod adventure. It's back together now so I can't look sorry. Here's a pic of my wiring though not sure if it will help. I did find a set of wires that looked like they went to another switch that were taped up with factory cloth tape. Maybe those are the same wires.

 

A. It's not factory
B. At 40 amps! It's not doing any good anyway.
C. I would remove it, and see what doesn't work, then just put the wires back together without the fuse.

 

Probably good advice.

 

It is the right colors for the illumination rheostat - so are you sure? There is also a wiper intermittent rate control rheostat also - so are your instrument lights variable?? if you unplug the fuse do they go out?

Alan

 

Okay, thanks guys!

I thought I'd read in the manual that the wheel on the right was the dimmer, or maybe I just assumed it. Upon closer inspection I seem to be missing the dial for the dimmer under the left side of the pod.

Why the hell anyone would replace the rheostat with a jumbo fuse is beyond me, but it's probably not the strangest thing I'm bound to find on this car.

 

Well if the rheostat quits working you get no lights. Connect these together and the lights come on full brightness. The fuse may have just been a covenient way to connect these or maybe an attempt to limit risk?

The rheostats aren't common parts - But I don't know why people don't just order the correct parts (they aren't even expensive)... but ???

Anyway find one at 928 specialists or 928 international.

In the interim you can find a simple part to link the terminals at most car parts stores - look for a 1/4" quick connect male to male jumper.

Alan

 

Actually that 40A fuse makes a pretty good jumper! I think I would add a round of electrical tape though - I don't like to see exposed metal that is carrying a current, however small. Just me.

 

Yes, it is a pretty good, quick jumper. Since my dash lights are never excessively bright, my rheostat is always at full power and it might as well be jumpered. It's a little strange, but definitely not the dumbest thing I've seen.

 

I think the ATX fuse blades are a little too big for the quick disconnects... may cause some damage - not good if you plan to reinstall a rheostat later. I think an ATC fuse would be OK - smaller and more likely to hand. But since you can buy parts purpose made to directly link these connectors - why woudn't you use those instead? - Agree a wrapping of tape is a good idea for insluation.

Given this is done I'm not sure I'd propose doing any different until a replacement rheostat is found - the comments were mainly for others with issues or a missing rheosat needing a temporary solution.

Alan