Headlights, etc., won't work when engine running

Post by **mgjh** » 22 Apr 2010, 15:51

Hi. I'm new to the forum, so please bear with me on my first post. I have an '88 240. When the engine is not running, headlights, radio, heater fan all work fine. When I start the car up & engine is running, headlights, radio and heater fan cut out. High beams still work as do turn signals, brake lights. I did a quick check (as per Bentley) on the alternator; battery is at 12.5 volts before start, about 13.5-14 volts while engine is running. Beyond that, I've really only done mechanical & am stuck with this electrical. Is it a relay? Thanks.

Post by **jblackburn** » 22 Apr 2010, 17:31

Twitch the key in the ignition switch once you start it. Does everything start working again?

Post by **mgjh** » 23 Apr 2010, 06:29

I went out this morning, started the engine up and now everything's working fine (by the way forgot to mention in my original post that I did check fuses and all looked good), didn't have to wiggle key or anything. The only major differences I can think of are that the car had been sitting over night and the temperature this morning is about 30 degrees cooler than yesterday afternoon (40 versus 70 deg.).

So, I'd love to think the problem's solved but I have a feeling that something will quit when I really need it (like headlights after dark). Am I going to be chasing gremlins? Thanks.

Post by **jblackburn** » 23 Apr 2010, 07:33

Electrical gremlins are all the fun of owning a Volvo!

My '85 Saab was exactly the same way. Things worked on their own schedule, not yours. Every now and then, the interior light would work at night and you could see where to buckle your seatbelt!

When it acts up again, try playing around with the ignition switch. They are a common point of failure in all Volvos, commonly act up with heat/extreme cold, and an easy fix to save yourself a lot of problems.

Oh, and didn't mention it before, but welcome to the site!

Post by **mgjh** » 23 Apr 2010, 18:32

Playing with the ignition switch did it. If I start the engine, then back the key off a little past 2nd position, everything works fine. Could the ignition switch also explain why startup is a little rough even with new starter, fully charged battery & good wiring? That would be good news as it looks like a pretty easy repair. Thanks!