Cigarette Lighter & Headlights == do not work at the same time??

ryan

ryan

True Classic
Hello folks,

On my '87 X1/9 I was trying to use a GPS unit plugged into my cigarette lighter. It works fine during the day, but I noticed that when I turn on my headlights, this switches power off to the cigarette lighter. Does anyone know if this is a "design feature"?

I was just now looking at the Bertone electrical diagram for all this, but still have quite a ways to go before I can decipher such diagrams. :grin:

-ryan
 
I had an issue on my 1989 X where the car stereo turned itself off when I turned on the headlights! Since then, I have carried out some work on ground straps and cleaned both battery terminals, and that seems to have cured the problem... for now... ;-)

Best wishes,

Mickey
 
Hey, thanks for the reply.

So I take it that the power to the cigarette lighter shouldn't shut off when the headlights are on, eh? :grin:
 
I am sure it's not meant to be!

On mine, once the lights were up and on, I could turn the radio on again and it worked fine. But there was a brief smell of burning wiring or components! Not fun when blasting along at 80mph on the motorway.

Can you restart that sat nav device once the lights are up and switched on?

Regards,

Mickey
 
Sounds like to me you have a bad ground to the lighter (or someone has been fat fingering the wiring). When the lights are on I would bet you it is getting it's ground through one of the bulbs, when you turn them on the path is gone. Take a volt meter and ohm the ground out and the + out (disconnect the battery or you will get bad readings on the ohm part of the meter).

John
 
Lighter socket

As the others have said the lighter socket should have power all the time. In addition to a potential bad connection in the (+) supply side, you could also have a bad ground.

Check the tab ground "blossom" under the left side of the dash, it has a lot of black wires (ground wires in late Fiats) going to it. The male and female parts of these connections can corrode, heat up, get loose, none of which makes for a good ground connection. Often just disconnecting and connecting the ground wires can clean the connection well enough.

I suspect the issue is in the (+) side though, the always-on power is supplied through the fuse panel (brown wires from battery) and branches off to the ignition switch where it provides key-switched power to the headlights and heater fan etc. And the lighter and headlight grounds are far apart. You might want to compare voltage at the socket with the lights on to what's at the battery.

Look for burned looking plastic connection covers and other signs of resistance. Consider the "brown wire mod" which provides another (+) wire to the panel and/or ignition switch.

Do you have your headlights on relays?

Hope this helps.
 
I'd probably run a dedicated hot right off an always hot source (brown wire at the ignition switch?) put an in line fuse holder on it and use that to power the light socket. I did that to install an "auxillary" socket for my iPod holder which I mounted on the right side of the center console so my defunct iPod (which only holds a charge for few minutes) is always hot 24/7. No room in the standard spot. I actually bought this 4 spot remote charger thing. And while it works (though it is super crappy chincey) there's no good place to mount it either. I was thinking iPod charger AND some little interior light controls and such but it got tossed into a pile on the garage floor.:lol:

I'd also recommend the brown wire mod, hightlight relays and maybe a dedicated hot off the battery to a little fuse block to power all the "accessories". I've cleaned up connections, brown wire mods to both ignition switch and fuse box, relays on high and low beam, relays on both wiper circuits and a relay for the solenoid. You can get a 10 back of relays with wire harness off ebay for $30 and be set for a long time! I currently have decent voltage all the time, fast wipers, brighter headlights, protected ignition switch (relays take the load of that delicate expensive thing). Knock on wood! All thanks to the fine folks at Xweb of course!
 
+1

Looking at the wiring diagram, that makes sense. If you do not have a good ground for the lighter, it will be grounded through parking / marker lights in series with the bulb that illuminates the lighter. A quick way to check this is to see what happens when you push in the lighter (to heat it up). If pushing in the lighter causes the light illuminating it to turn on and the lighter does not get hot, it would point to a ground problem. I believe the lighter is grounded through the ground tree under the left side of the dash.
 
Thanks everyone. I'm moving this week, but after that I plan to see if I can shed more light on what is going on. I'll try to take some readings and some photos and see if I can figure out what is going on, or if you all can help. :]
 
Ummm... OK Ryan

ryan said:
I'm moving this week, but after that I plan to see if I can shed more light on what is going on.
Click to expand...

Just don't plug anything into the cigarette lighter at the same time you try to shed light on the situation. ;)
 
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