neilh

My 81'auto car has just developed the infamous 'all lights on the dash stay on' issue. The strange thing is they all go out and everything is normal if i shift from park to any gear and back to park, only to randomly come back on, when either shifting gear or opening the drivers door causes them all to go out.
I have checked the seating on all the connectors on the pod, the ignition switch itself, and the grounds under the dash.
So what or where next?

TIA
Neil

Randy V

Hey, Neil! How's life in NC? Still driving the convertible?

Looks like you covered my suggested culprit - the ignition switch.

neilh

yes, new Roger switch went in and did not help
Nc is great, thanks Randy. The convertible was my 914, long gone, just have to divide my time now between the 81, 84 and 86 cars, and my Ford 'A' street rod !

Thanks for reply, I expected more, maybe someone else will chime in, and yes, I did search for those that will surely ask....

Best regards

z driver 88t

Here's a long shot - maybe one of the electrical experts can chime in (Alan?). The only "all dash light on" failure I've experienced was when my alternator died - made everything light up like a Christmas tree. Your car is an auto. Does it have to be in "Park" to start? Is there anything linking the alternator exciter circuit to a "Park" switch that should be triggered at start-up? And by manually shifting it out of park and back in, it triggers the switch and everything runs normally? Just a thought.

Mrmerlin

remove the brush holder from the alternator and inspect the brushes,
if they are worn only use a new Bosch regulator part or you will do the job twice.

NOTE also check the belt tension,
the highest draw on the alternator is at idle just after starting

neilh

Thanks for suggestions, here is what I found. I removed the ash tray to see if anything behind there was getting moved around - I found that with the auto in Park, the sliding plate that moves with it was pushing on the ground wire attached to the cigar lighter. The movement over time had caused the ground wire to fray and was intermittent. I remade the ground connection, routed everything away from the sliding plate, and have not seen the problem again, yet. It was occuring every time. So now on a test sample of about 2 dozen starts, still have not seen all lights on problem.
Stan, I did put a storage scope on the hot post and the alternator / battery voltage on a fully charged battery is over 12V.

Coincidence that it went away, very likely, and i can see nothing in the diagrams that would suggest an intermittent ground at the lighter could trigger the lights.

James Bailey

opening the doors also switches a ground.....

neilh

Jim haven't seen you for years, I used to drive up to 928intl from San Diego to pick up parts from you before you departed ( 928intl that is ). Yes, I did check for a poor ground from the door, but didn't find anything.
Cheers
Neil

neilh

So, after 15 light free days, the problem came back, and this was a 5 min zero $ fix. I noticed by accident that if i pressed on the drivers foot rest all lights either came on and went out. I removed the foot rest to get to the central warning box, and as i pulled it out the black connector popped out as well. Plugged it back in and secured, and now no problem. IIRC the last time i accessed that foot rest was about 7 years ago when i undid it when i installed 996 seats, must have been loose for ever.
Why can't they all be this easy

The Deputy

Thanks for the follow-up. It's always nice when folks finish the topic with the solution.

Brian.