Baffled - gauges dead, only work when key held in far right ignition position

[betheclient]

My E30 buddy and I are stumped, and I couldn't find a similar combo of symptoms through searching archived posts. I suspected the SI panel batteries until the AC fan stopped working..

1. While cruising in 4th, suddenly felt a shudder and all the gauges on the dash went dead. Engine/tranny/AC/power windows still worked fine.
2. Turned car off then on again. Now the speedometer works, but all other gauges are still dead.
3. After driving car for a few days like this, the AC fan stops working.
4. Strangely, the AC fan works and the usual red LEDs (e.g. brake lining) light up when I hold the key to the far-right position (igniting the engine). But when I let go and the key goes to the normal "On" position, they stop working.

Does anyone have an idea/suggestion?

Thank you.

[dnguyen1963]

I suspect that you have a bad ignition switch or bad ground near the steering column.

[Gregs///M]

Replace fuse 10, 12, and 21 with new fuses. Don't bother checking or using 25+ year old fuses, just get new ones. 7.5A each. That should fix your problem.

[betheclient]

The collective expertise in this forum never ceases to amaze me.

Thanks guys, will work on these and report back.

[betheclient]

The fuses worked like a charm. Thanks a lot guys.

[betheclient]

Strangely, after replacing those fuses with brand new 7.5 fuses, #10 repeatedly gets blown.

I had to replace it 3 times in just 2 hours of driving, the tach/oil level/temp/AC would all just stop working suddenly while driving. Stopping the car and replacing the fuse with a new one would fix it, only to see it blown again a little later. Any ideas?

[dnguyen1963]

Intermittent short somewhere in your system. Download the electrical diagram and track to see which wires/components are controlled by fuse 10. This is tedious work.

[Gregs///M]

Try removing the cluster and inspecting the wiring harness behind it. Also check behind the radio, especially if you have an after market unit.

[betheclient]

Thanks for the suggestions, troubleshooting wiring is indeed time-consuming. Will try to find time to look into it this weekend. Might also be the illumination power wire in the stereo wire harness grounding against metal in the dash (had an aftermarket stereo installed recently).