H4 Upgrade kit is here

traveler · 09-25-2003, 06:32 PM

I just received the Bosch H4 headlight upgrade including the high power headlamp relays (one for each side). All the parts are here and I have read the technical article on installing the headlamps but there are no instructions anywhere that I can find on installing the relays.

Also, what's the process for aiming the headlights without a headlight aiming tool?

traveler · 09-26-2003, 03:33 AM

Anyone?

derkpitt · derkpitt's Garage

This should help a litte,
http://lighting.mbz.org/tech/relays/relays.html

Wavey · 09-26-2003, 04:28 AM

Quote:

Originally posted by traveler
Anyone?

Here are some Pelican links which may or may not be helpful (don't have time to review them this morning):

Umpteenth H$ upgrade question...

headlight upgrade,whats the deal?

Question about H4s

http://forums.pelicanparts.com/search.php?action=showresults&searchid=194511&sortby=lastpost&sortorder=descending

Where / How To Mount Headlight Relays?

H4 Installation Problem

http://www.autooptiks.com/aiming.html

Hey - I'm in Edwardsville - let's get together some time!

jmohn · jmohn's Garage

Quote:

Originally posted by derkpitt
This should help a litte,
http://lighting.mbz.org/tech/relays/relays.html

This site also has a good procedure for aiming. As well as other good general lighting info.

Jerry M
'78 SC

traveler · 09-26-2003, 10:02 AM

Thanks to all for the links. I'll let you know how it goes tomorrow when I do the job.

traveler · 09-26-2003, 07:38 PM

I did some preliminary work this evening. I pulled the right headlight and discovered that I need the three prong (U shaped) plugs for the new H4 bulbs. I'll get those tomorrow.

Also, I purchased the 2 relays from Pelican and I noticed that they don't have any way of being mounted. Any suggestions?

Finally, I noticed that I have 4 fuses in the fuse box for headlights (2 for the low beams and 2 for the brights). Should I install 4 relays? or should I just combine the 2 low beams through one relay and the 2 brights through the other?

1982911sc · 09-26-2003, 07:48 PM

Can't help you on the relay question, although the PO installed some relays and basically the wires just hold them. He never did attach them to anything. I just converted to the H4 Beam (Hella) only. Not the entire kit. After installation, I just waited until dark went to a car wash with a flat wall parked twenty feet out and just used the aiming screws. it only took about 5 minutes, I am thinking it would probably be similar for yours. You will also notice with the H4's you get much more light ACROSS the road, not only brighter.

Quicksilver · 09-26-2003, 09:58 PM

Here is my solution. It doesn't have to be this big but I have a bunch of lights and I added a curcuit breaker panel to drive them.

I bent the aluminum plate over a 2x4 so it had 'lines' similar to the stock fuse panel. The 2 fender bolts hold it in place.

Wayne

traveler · 09-27-2003, 04:12 AM

Wayne,
Nice job!

larry47us · 09-27-2003, 04:22 AM

My shop is installing an H4 kit in my 73E. He said that he has never used relays and has never run into problems before. Is there a reason why you should use relays in this installation?

larry

RoninLB · 09-27-2003, 05:16 AM

Quote:

Originally posted by larry47us
Is there a reason why you should use relays in this installation?

didn't the listed sites imform you?

traveler · 09-27-2003, 05:16 AM

Larry,
Based on everything I've read, if you're using the higher power H4 lamps it could fry the wiring in the steering column and dash. Using the relays limits the amount of current running through those (smaller) wires. This is particularly true of older cars in which corosion will raise the resistance in the wiring, hence more heat. My feeling is better to be safe than sorry. Even though it's a little more work, I'm putting the relays in.

Quicksilver · 09-27-2003, 10:04 AM

Quote:

Originally posted by larry47us
Is there a reason why you should use relays in this installation?

larry

Getting correct and consistant voltage is one reason but the best reason is to protect the headlight switch. They are way too expensive and a relay is less then $10.
Even with the stock bulbs the contacts in the switch will degrade over time as the little arc when the switch turns on and off. It acts like Electrical Discharge Machining so the switch is going to fail someday. I would rather have the weak link be a cheap accessable relay.

If you want to run a higher wattage bulb it is really necessary. I still have the H5s so I put an "all weather" (yellowish) 80/100 watt bulb in. The yellowish light gives less glare and leads people to believe that they aren't overly bright.

Wayne

Quicksilver · 09-27-2003, 10:47 AM

I just realized no one answered your original question, which was how to hook up the relays.

The Porsche wiring scheme is a little odd in that the fuses are not upstream of the switches. (Apparently Porsches are immune to wiring shorts under the dash!

) The circuit 'flows' down through the fuses. The wires above the fuse come from the switch and the wires below go to the headlights. You will see that each pair of headlight fuses (high-beam and low-beam) have a single wire coming from the switch. Use this as the signal to 'kick' the relay. Each pair of fuses has a pair of wires that runs to each light. Connect both of each pair to the output of its respective relay. The relay will need a small ground, which you can wire to any good ground that you would like.

The last and most important piece is you need power to drive it. The power must be fused so I would recommend a 10 or 12 gauge wire with a ring terminator large enough to go on the pinch bolt of the positive battery cable. You could hook this to any type of fuse/circuit breaker but the simplest solution would be to run it to the top of the existing headlight fuses. I would then hook the bottom of each fuse (in pairs) to the feed connector of their respective relays.

If you want to run high wattage bulbs I would recommend replacing the wires from the fuse block to the headlights. It wasn't meant for that high of amperage.

Good luck
Wayne

RoninLB · 09-27-2003, 10:57 AM

I run 130/100w because it's doable.. our headlights sit relatively low to the ground.. alignment becomes more delicate.......Ron

larry47us · 09-27-2003, 12:27 PM

Traveler and Wayne:

Thanks for the quick answer to my question. I had read about the potential of problems with the headlight switch and the higher voltage. My shop says that he has never had any problems with it, but . . . . . better safe than sorry.

I will ask him to do the relay installation.

BTW, Ronin, I was trying to get a quick answer without reading all of the 6 threads that were written. Help me out here, gimme a break, and cut to the chase, OK??

larry

RoninLB · 09-27-2003, 04:04 PM

Quote:

Originally posted by larry47us
, gimme a break,
, OK??

OK

LOL.....Ron