Headlight function question

jhelgesen · 11-11-2011, 04:35 AM

Been a while since I drove a 911 at night, but had to last weekend. Every German car I have owned, the lights would not come on until you turned on the ignition, otherwise just got running lights. My 84 carrera will now run the headlights and high beams just by pulling the switch on.

Here is the bad part, when I turn the ignition on, the high beams go on and stay on. Hi or Lo beam selected, constant high beams.

Any thoughts out there? Was going to replace the turn signal switch, but not sure this is it.

bkreigsr · 11-11-2011, 06:02 AM

Could be a little of each issue. Turn signal switch, (especially the 84-85's) and the light switch.
If you have had your sound system replaced, a lot of installers will use the light switch as a source for their hot wires and totally screw up the switch functions.
Bill K

masterdave · masterdave's Garage

Not sure if those cars had a headlight relay, but its a good place to start.

Rot 911 · 11-11-2011, 06:29 AM

Quote:

Originally Posted by masterdave

Not sure if those cars had a headlight relay, but its a good place to start.

Nope, no stock headlight relay.

jhelgesen · 11-11-2011, 06:30 AM

Quote:

Originally Posted by bkreigsr

Could be a little of each issue. Turn signal switch, (especially the 84-85's) and the light switch.
If you have had your sound system replaced, a lot of installers will use the light switch as a source for their hot wires and totally screw up the switch functions.
Bill K

I pulled the mother of all 90's sound systems out of the car, could be part of it. When I pulled the fuse from the high beams to try and not blind all oncoming traffic, I lost all dash lights and the radio.

jhelgesen · 11-11-2011, 06:34 AM

Looks like I have a date with a wiring diagram and start over from scratch.

Barrpete · 11-11-2011, 06:58 AM

From the factory the dash lights on Carrera's were not fused at all. If you pulled the high beam fuse and the dash lights went out a PO has definitely made some wiring changes.

Flat Six · Flat Six's Garage

Quote:

Originally Posted by jhelgesen

Looks like I have a date with a wiring diagram and start over from scratch.

+1

May be as simple as headlight circuit connected to wrong terminal on the back of the ignition switch -- I'd definitely start there.

And yes, IMHO some kind of headlight relay system should be done at the same time. It's not just a lighting performance upgrade; it's a safety upgrade, too.

Good luck

jhelgesen · 11-11-2011, 07:10 AM

Quote:

Originally Posted by Barrpete

From the factory the dash lights on Carrera's were not fused at all. If you pulled the high beam fuse and the dash lights went out a PO has definitely made some wiring changes.

Party under my dash board, oh joy!

MrScott · 11-11-2011, 08:09 AM

Before energizing the dash lights I'd suggest verifying your dash lighting is fused:
Dash lighting fuse installation
A short from incorrect wiring could turn this into a much bigger project. A couple of switched connections wont trip a fuse like a modern car, they'll melt your wiring.

jhelgesen · 11-12-2011, 01:08 PM

Brake lights works again, new switch, but only when car is turned on.

DRACO A5OG · DRACO A5OG's Garage

So you rarely drive at night? So you don't know if this was all of a sudden or as others have posted wire in the wrong fuse terminal.

+1 check the fuse terminals, it is very easy to place the wires in the wrong terminal if worked on by PO.

If that doesn't do the trick then it may be time to re-fresh the turn signal stock. Search under poster WON, he posted how to service it and if you search in the same thread under my name, you will see all the terminals on the stock that needs to be addressed. or Buy a new one.

A head Light relay is a good idea and it will allow full voltage to the lights.

Brake Light Switches only work with the ignition in the "on" position or when the car is on. so that is normal.

Jim

P.S. I have fuses on my Gauges, Footwell Blower, AC Front Condensor Blower and Head Light relays. Yes, I need a life

jhelgesen · 11-13-2011, 08:43 AM

Found it.

Swapped out TS switch for a used one on the shelf, no change. Looked at WON's post, both switches had bad contacts. Bent contacts on installed switch, worked but acted funky. Dash lights only worked with high beams.

Started looking at fuse panel, remembered I have a bad parking light up front, it had taken out a fuse, so looked at it again, found a hot wire. Pulled the fuse to the right park light, low and behold, headlight work properly now.