headlight dimmer on passenger side '72T

[sunlion]

hello, my headlights/parking lights are significantly less bright on the front passenger side than the driver's side, see photo. i have 100W H4s and noticed that the passenger side does work unless the driver side is installed and switched on. Perhaps they are wired in series. Is there no headlight relay? Also, the carillo h4s are in sad shape so I'm in need of a decent replacement set. Any input or direction to prior threads on this matter is appreciated. Best Cheers Regards (BCR) Ravi.[ATTACH=CONFIG]337240

[NeunElf]

hello, my headlights/parking lights are significantly less bright on the front passenger side than the driver's side, see photo. i have 100W H4s and noticed that the passenger side does work unless the driver side is installed and switched on. Perhaps they are wired in series. Is there no headlight relay? Also, the carillo h4s are in sad shape so I'm in need of a decent replacement set. Any input or direction to prior threads on this matter is appreciated. Best Cheers Regards (BCR) Ravi.[ATTACH=CONFIG]337240

There is a relay but that's probably not your problem. The right and left side power run together to the fusebox where there are separate fuses for the right and left side.

If all the lights are dim on the right front side, the problem's probably grounding. The SL35 wiring diagram shows all lights on that corner having a common ground. I would suggest you find and clean that ground. I'm afraid I can't be much more help--aside from the wiring diagram I don't have the manuals for such a new car.

By the way, both horns ground with the left side lights.

As far as replacing your Carillo H4s, you have lots of choices. You can get Cibié H4s from Aardvark International and Hella H4s from Sierra Madre Collection and many other sources.

I have Cibié H4s on my 356A (with relays switching 6V power directly from the battery) and Hella H4s on my 911 (with relays at the fusebox). They both work well.

[boxster03]

H-4s in sugar scoops ? how does that work ?

[jrbennett]

boxster03, take a look here

http://www.early911sregistry.org/for...eam-Headlights

[boxster03]

thanks - never seen a car with that - wonder how many US car owners did that in the day after they purchased their cars with us spec sealed beams

[NeunElf]

thanks - never seen a car with that - wonder how many US car owners did that in the day after they purchased their cars with us spec sealed beams

I didn't own a Porsche until 1997 but I put Cibié "Z-beam" H4s on my Land Rover Series III shortly after getting it in 1974.

There are probably a lot of cars with H4 replacements for sealed beams. They're easy to find: I bought the Hella H4s on my 911 at Pep Boys. The H4 replacements don't look dramatically different from sealed beams but they're not hard to spot once you start looking.

By the way, at the big 356 Club Dana Point Concours d’Élégance (26 July 2015) the rules call for penalizing cars in the "full concours" class if they hgave H4s as opposed to "original" headlights.

[ptrsbtrs]

You can always call me too.
I'm willing to help.

[RSTarga]

There are no relays on the headlights, unless someone installed them. Highly recommend adding them. Check all your grounds and make sure all your fuses are ceramic and making good contact.
You can take a voltmeter and check each connection to make sure you are getting full current at each connection.

[sunlion]

Thanks for all the replies gents. I cleaned all the fuses and grounds as they were moderately corroded, no difference. I used the wiring loom which feeds the right side to power the left side and the left side was still bright which tells me the wiring from the fender to the headlight bucket and turn signals is probably the problem. I'll pull this loom, clean it and report back.

Now I'm confused about what headlights are correct for my car. According to the PET, 72- on has 'real' H4s and not 'sealed beam H4s.' Darn, another quest to pursue.

Hi ptrsbtrs! I'll call you.

[NeunElf]

Thanks for all the replies gents. I cleaned all the fuses and grounds as they were moderately corroded, no difference. I used the wiring loom which feeds the right side to power the left side and the left side was still bright which tells me the wiring from the fender to the headlight bucket and turn signals is probably the problem. I'll pull this loom, clean it and report back.

Now I'm confused about what headlights are correct for my car. According to the PET, 72- on has 'real' H4s and not 'sealed beam H4s.' Darn, another quest to pursue.

Hi ptrsbtrs! I'll call you.

Assuming you have a US-spec car, I'm pretty sure the correct headlamps are the "sugar scoops."

For illustration 905-05, you may be looking at this line for the left hand steering H4s

POS.	E	Part Number	Description	Remark	Qty	Model
			HEADLAMP H 4	72-
1		911.631.102.00	HEADLAMP NOT FOR	/LL	2	(USA)

I think we're intended to read that as "NOT FOR (USA)" Illustration 905-00 shows the "sugar scoops" as the units for the USA and there's no change indicated at -71 or 72-. The "sugar scoops" stayed on USA-bound cars till 1989.

Don't let me dissuade you from putting on a pricey set of 911.631.102.00 H4 units if you want them, but they weren't originally on USA-bound cars.