Crazy headlight elec problems

NKN84944 · 07-17-2005, 12:00 PM

Hey guys, so my headlights quit working on me a couple days ago. I had this problem with both going out at the same time a while ago and figured out that it was a loose wire in my light switch. Unfortunately this is not the case this time.

My #3 fuse on the additional board for the blower and rear defogger keeps blowing, but somehow they are both still working! So I am totally puzzled, is my board wired differently than everyone else possibly? I am about to back with a volt meter and try to figure out what is going on.

I have checked the wires by the pop up mechanism and replaced the bulb with no luck. Any ideas?

SoCal Driver · SoCal Driver's Garage

When both headlights go out it's the switch or the wiring to the switch. Each element of each headlight has it's own fuse. The battery connects directly (almost) to the headlight switch and the switch to the buss for the four fuses.

Which fuse 3? the one on the aux 9 fuse buss or the one on the 15 fuse buss?

1 through 4 on the 15 are the headlights.

3 on the aux 9 is one of the two cooling fans on the radiator. Most likely the older 3 bladed unit with a frozen bearing. This does need to be replaced or you will kill the engine from over heating.

Fuse 4 on the aux 9 is for rear window defogger. If it's been reconnected to 3 then there are some serious problems with the wiring.

http://www.clarks-garage.com/shop-manual/repair-procedure-index3.htm#fuses

http://www.clarks-garage.com/pdf-manual/elect-10.pdf

NKN84944 · 07-18-2005, 03:18 PM

Thanks So Cal! I think you are right after testing the switch with the voltmeter, it isnt sending any power on the wire it is supposed to when the lights are turned on. Time to get that replaced, although I think I am going to take it apart and mess with it first.

And you were also right about the cooling fans, but only the drivers side isnt working. The other fan still runs, even with the blown fuse! This doesnt really make sense to me, but I am sure someone else on here knows the reason for this.

SoCal Driver · SoCal Driver's Garage

Check the links I posted. There are two fuses for the two fans. Like the headlights each fan has it's own fuse.

With the car off and cool reach down and see if you can turn the fans. If one is frozen you'll know.

bigyagi · bigyagi's Garage

hi NKN. you can take the headlight switch apart, but be careful, as there are very small springs in there, along with a small diameter ball, just waiting to drop into some totally inaccessable place! you will have to pay attention to the 3 contacts in there. they look very alike, the topmost one is somewhat different, but the ones on each side are slightly different and have to be installed in their original positions. the contacts, and the area that they slide over, get all "carboned" up, just like the window switches. not sure if its worth cleaning/repairing. hope this is of use to you!
bob.

NKN84944 · 07-20-2005, 10:04 PM

Well I took the switch apart and found that the contacts for the low beams were covered in a layer of plastic from the housing! Something got really hot in there and melted the plastic really bad. I tried scraping all of the plastic off and cleaned the contacts, but it still doesn't work... not really surprising. Looks like its time to replace one of the last original switches in my car.

Thanks for the help guys

Nate

SoCal Driver · SoCal Driver's Garage

If you have recently installed high intensity head lights then yes you will melt your light switch. Most anything over stock wattage needs to have relays installed to take the load off of the light switch.

IceShark · 07-23-2005, 01:21 PM

As Hugh noted, that headlight switch is a disaster waiting to happen. You probably need to replace it.

For some odd reason Porsche didn't put in a relay(s) for the headlights. So all the current to the bulbs is going through the switch itself. Bad design.

You have an '84 so the switch failing on even normal 55/60 watt bulbs isn't a great suprise.

I sell a headlight upgrade package. Some people don't want to buy the wiring harness part of it but still want to run 90/100 watt bulbs in the E-Code Cibies. I tell them that isn't such a good idea as the headlight switch is going to give out sooner or later. And they may melt other things, like their wiring.

Some people do it anyways. You can lead a horse to water ...

Zero10 · 07-23-2005, 01:39 PM

Yep, the PO of my car installed 90/100W bulbs with no other upgrades. A swap back to 55/60W bulbs actually yielded INCREASED light output. I was seeing 8.0-8.5V at the bulbs with the 90/100W bulbs in there... that's just sick.

All of my headlight wiring has turned a rather ugly color, and will all need to be re-run. Don't take Dan's warnings lightly. I have no idea how long the bulbs were in there, but still, scary. I'm amazed the car hadn't already caught fire.....

IceShark · 07-23-2005, 02:20 PM

Quote:

Originally posted by Zero10
Yep, the PO of my car installed 90/100W bulbs with no other upgrades. A swap back to 55/60W bulbs actually yielded INCREASED light output. I was seeing 8.0-8.5V at the bulbs with the 90/100W bulbs in there... that's just sick.

All of my headlight wiring has turned a rather ugly color, and will all need to be re-run. Don't take Dan's warnings lightly. I have no idea how long the bulbs were in there, but still, scary. I'm amazed the car hadn't already caught fire.....

Private message me with the PO's name and I may be able to tell you the history on that. 90/100 H4 bulbs are sort of unusual in North America. I think I sell most of them.

I picked the 90 watt dipped beam filament due to tradeoffs between output and filament life.

Boy, 8 some volts at the bulb is sick. May as well tape some flashlights to the fenders.

Zero10 · 07-24-2005, 07:29 PM

They were 90/100W Osram bulbs. I actually thought they were common until you said something. I have never gone looking for them though.

No need to private message, they were so rude I have no problem disclosing any of their information, lol.
I bought the car from a guy named Igal Eli (or was it Eli Igal?) A Iranian fellow in NYC, who bought it from a family in NC/TN, the Hynemann's.
It went around that family probably 3 times. I have titles, registrations, receipts, etc, with the names of probably every family member. It seems they actually took decent care of the car, but I presume these bulbs had been in there for a while, so I would imagine they put them in, since Igal (or Eli) only owned the car a couple weeks.

I only noticed because the driver's side bulb burned out. I had sealed beam's on my 86, and the light output was comparable. Now with 55/60W bulbs the light output is almost tolerable. Perhaps with a wiring upgrade it will be decent?... I want to build HID buckets, so I'm holding off on most lighting upgrades until I can make up my mind.

IceShark · 08-24-2005, 10:21 AM

I didn't sell anything to them and the 90/100 bulbs I have are made by Philips/Narva. That wattage combo is usually an European origin so I'm sure Osram makes them also. Osram's child, Sylvania, doesn't though and many auto stores in North America stock Sylvania bulbs. That is why they are hard to find. Best bet, outside of me, would be a motorcycle shop. And you don't really want to get over a 90 watt filament in low beam as higher wattage will burn out too quick. 90/100 is a good position with a fine E-Code lens.

The list of people that wanted and tried to do HID upgrades is very, very long. I looked into it myself 4 years ago. The big problem is cost Even with buying the lenses out of Europe the cost would be well over $1000 going towards $2000.

With my "FullBoat" headlight package with new wiring and E-Code Cibie lenses running 90/100 watt halogen bulbs you are up at HID levels anyway for under $400. People have lined them up against Bimmers and Benzes with HID and say the halogen are equal or better.

Which is what I concluded also so dropped cooking up some HID solution. HID just wasn't worth the cost and trouble. You are in Calgary and there are a couple of my FullBoat headlight kits up there. Don't know how big your town is but you could probably hook up with one of the guys and see the headlights in action.

Tom Hayes · 07-17-2006, 03:47 PM

Removed the switch, still hot and the switch and the loom were melted on one wire connection.

Ordered the headlight switch, but I can not locate a headlight wiring loom, suggestions?

So, my question is how to prevent this again? The light bulbs have been in the car for at least 2 years, the switch is 20 years old, poor electrical design (I know it 10 years old) and if I get another 10+ years out of this switch; great, but I don't expect to own this car that long :-)

When I was figuring out this problem in the dark, I manually lowered the headlights and (remembered there was a catchy/stuck feeling when I first started lowing them); so I am going to be lubing the linkage and making sure there is no binding. Also, double checking for shorts in the loom. Anything else I should be doing?

Tom Hayes