I haven't driven my 745t at night in quite a while and only recently got the interior back in after fixing a water leak. I drove it for 3 months with only seats. No carpet, floor padding or console from the A/C controls down. Anyway, all the wiring was exposed.

Now, heres the question part. Last night I got in the car, started it and turned on the headlights. The dash lights didn't come on and fiddling with the dimmer didn't have any effect. I also noticed the speedo was reading 45mph. When I clipped my seatbelt on the speedo went to zero and the dash lights came on. Seatbelt out, instrument lights off and 45mph, seatbelt in, lights on and zero.

With the headlights off it doesn't matter. The speedo stays at zero, seatbelt on or off.

Also, I noticed, when I put the console back in, the seat heater switches are always illuminated. Heaters don't work but that's not new.

I'll check for fuses but suspect an open ground somewhere. The Haynes schematics are ok but I'm fishing for ideas.

Thanks,
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Erwin in Memphis, '88 745t 183,000 miles, '95 855t For Sale

I ahve the same problem with my 1986 Volvo 760 turbo as far as the gas and alternator guage sticking when I start the car. I push in the peg by the gas guage and hit the upper dash panel and it frees it up. I hope to have this fixed when I get my intermiiten speedometer fixed.

Erwin, if you find and improve the grounds and still have troubles, it is possible that your water leak has damaged some of the basic body conductivity.

You might try using some jumper cables to connect some of the ground terminals together. For instance, connect the grounding terminals near the computer in the right footwell to the ground terminals in the left front fender area.

Don't whip a dead horse, most of the grounding locations have extra terminals, run a ground wire from location to location if you have to.
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3 8s & 2 7s 740,000 miles total

Connecting/disconnecting seatbelt is turning the seat belt warning on/off hence the relation. Sounds like ground wires are disconnected/broken to dash cluster.

Thanks for the replys,

When I had the seats out I noticed the driver's seatbelt latch connector was pulled loose. There was a reason. I put everything back in order when I put the seats back in and I'm sure that's when the problem surfaced (for me). Yesterday I pulled it open again and the speedo bounced around while I was fingering the contacts. Pulling the green wire loose of the switch "fixed" it. I'll investigate when I pull the instrument panel out. I agree there's likely an instrument panel wiring or circuit board issue. Lately (before the interior was put back in) the gas gauge and voltmeter don't come up without a slight whack at the top of the console. Then they're fine till next time.

BTW, There wasn't enough rust to compromise any body grounding. Just a few light spots on the interior floor and one dime-sized hole I cleaned, treated and sealed with marine putty/epoxy.

Regards,
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Erwin in Memphis, '88 745t 183,000 miles, '95 855t For Sale