Happened recently. On my 1990 740, lighter is working with less power. Looks like electrical currency amperage is low. It can charge cellphone, but can't feed GPS for longer time. Any idea what may cause this?

 

GPS doesn't use hardly any power. not even 1 amp at 12V.

will it heat up the lighter ? thats like 10 amps.

when I have GPS power problems its usually that the stupid plug won't stay firmly seated and vibrates loose.

 

Welcome to the forum Bobvol

"but can't feed GPS for longer time."

What actually happens ?? Are you sure you're plugged in ??

 

I agree it's likely a contact problem. Using those for lighting cigarettes puts a lot of crap and corrosion in there. It used to be easy to find generic replacement sockets in auto accessory stores, but not so much anymore. You could take it out, take it apart and clean it.

 

Thanks for replies. It has some contact at least, because while GPS is turned off, when I connect power cord to lighter, GPS will turn on. And I checked same GPS with my other car and it works fine. Cellphone charging seems slow too. So, that's why I think something wrong with lighter. I'm not smoker and don't have lighter. With your suggestion probably I will take off whole socket and clean it. Days are now cold and short so I'm not much into it right now. By the way it seems another problem happened same time. Coincident, I guess. My windshield wipers work. But when I turn on washer, water sprays but wipers won't move. Usually they work together when you use washer, right? Now water sprays, then I have to turn on windshield wipers. That's another kind of puzzle...

 

the wiper control stalk has a whole pile of different switch contacts in it, my guess is the bit that causes the wipers to cycle when you hit the washers is fubar. Also, there's a relay/module (its a relay plus electronics) thats invoked for both intermittent mode, and wash mode, its possible thats on the fritz. on my 92, this is the 'C' relay, on the forward-most row of the relays behind the ashtray (farthest from you), and 2nd from the right. on my 92 its part 6849780, OK, FCPeuro says it fits ALL 240/740/940, https://www.fcpeuro.com/products/vol...-front-6849780

 

There is a ground terminal cluster inside each front fender, just back of the headlights. Loosen and re-tighten these with an 8mm socket (if I recall). This will usually solve a variety of weird electrical problems.

 

On a 7/9, there's also grounds inside the cabin, one on each side of the car just forward of and below the door hinges, and I think there's another one on the tranny hump area.