so, the H4 Headlight Upgrade Kit on pelican recommends a high-power relay for the 100 watt bulbs.

now the stupid question:

do i just need one or do i need one for each headlight?
Andy

One for each - you have two power wires -a fuse for each headlight, yada, yada

One for high beams, one for low. One for the left side, one for the right. That makes FOUR. I would use the generic 40A VW relays. 141 951 253B. They're less than 5 bucks apiece. The Cap'n

thank you sir! that makes perfect sense, just wanted to confirm ...
Andy

100w high beams right?

100 watt low beams wil piss off lots of people... (so do 6 lights LOL)

Or just one. It really depends on how much power the relays will handle, how much current (and power) the lights draw, and so on. It is not a Bad Thing to not have a separate relay for the low beams, and to only have a single relay for the high beams. You would "daisy chain" them, the way a lot of things in the car already are done (e.g., horns, foglights, etc.).

Four separate relays is the ultra-ultra safe way to go. I personally would do one or two--a single for the highs, and either stock low beam circuitry or a single relay for the lows.

Just remember to put a fuse in the line going from the battery to the relay!!

--DD

Yea, whut he said - don't really need ones for LOW beams - those are still low power - even at 65 watts

55/100

Andy

yeah, four is best, that way a single fuse failure won't totally kill your lights. probably way many cars have a fuse for each, hi r, hi l, lo l, lo r.


a nice source for little square relays for a buck or less each is Pick your Part. grab the metal can ones, with standard 1/4 in male press on terminals from slightly older model BMW's, they got a bunch usually on the driver side front of engine bay I ahve used them in my Vanagon, as an upgrade, and my kit car. they make both a single trhow, and a double throw relay, the single seem to be more common, just pick up four single throws, thats all you really need.

run multible fuses to prevent fuse blowing from leaving you in the total darkness.

You may find that simply going to relays increases your voltage enough to make one think you have hi watt lights, when you stillhave the stock ones installed!

Check this place out. They even ha amber head lights

http://www.rallylights.com/hella/H4.asp

Mark

andy -

are you going to use Hella or cibie H4 housings?

Hell'ya
Andy

I just installed the 55/100 bulbs myself. I haven't turned them on yet, knowing I should upgrade relays.

When doing the search I came across this thread. How exactly does one set up these individual relays? I'm not good at creating circuits off the cuff. I did that on a 912 some years past and melted many wires.

A simple diagram or description would be very helpful. Thanks!

Call me foolish but I have put H4's on both my old 924 and my current 944, never installed a relay and have never in 5+ years had an issue.

knock on wood...but me, too, and i drive my 914 daily. it's also been 5+ years since i upgraded. guess i should thank my lucky stars and go make things "right." but then again, if it's not broken... ok, i'm going to pretend i didn't stumble upon this thread...

I drive to work early in the morning on a dark, back-country road. The last thing I can afford is to lose my lights. I don't want to take any chances.

More than 4 lights are illegal in CA (quad headlights count as 2). That's why you see the light covers on those ridiculous light bars on "off road" pickemup trucks. If you have fogs and driving lights, one pair has to be bagged. The Cap'n

A 944 H/L switch costs 40 bucks, a 914 H/L switch is NLA. All of a sudden, relays seem pretty attractive ....................... The Cap'n

http://en.wikipedia.org/wiki/Relay

Basically, you want your headlight switch to be the control part of the relay circuit while the fused current that comes directly from the battery is switched on/off by the relay.

That way, you don't run all the amps needed for the H4 bulbs through your headlight switch ...
Andy

Wow, got my H-4s from AA, but don't remember any notice of having to upgrade a fuse or anything like that. I'm glad this was brought to my attention.......Cap n', you just had to remind me of those ridiculous California ordinances, didn't ya ? I just posted a thread on their crap. I guess I'll have to find some bags for the fog lights now. What is their reasoning behind not being able to have four, and two must be covered, when they aren't even on ? Well, at least I fixed one of their other ordinances I got pulled over for....the no front Liscence plate, but I'm sure they will come up with something else again .......

It all depends on the bulbs you are using. I upgraded to the Hella H4s and stuck with the stock wattage 60/55, so I don't need to run them straight from the battery. You only need relays if you go with the 100w high beams. The standard H4 is plenty bright for my purposes.

Yep, Les is right. Its not the H-4s, it's the increased wattage that can be used if one chooses...

For H4 headlights did you get some sort of housing and then the little halogen bulbs, or is it a sealed beam light?

If its a housing, is there a specific part number or must we go to Pelican for the parts??? I mean can I go to NAPA and get the right sized housing...no clue about this...

Also..where are you getting the battery power from? Did you run new lines (four) from the battery, or did you run one up to the front trunk? Or, are you getting it from the main feed at the fuse box???

RIch

Mine are the housing with replaceable bulbs. Hella has a nice glass one, there are some cheap plastic ones on ebay, which I have heard suck.

Hella H4

If you go with the 100w bulbs you'll need to get power straight from the battery as the fuse panel can't handle it. The original power lead for the headlights, becomes the switch for the relay.

Here's a pretty good read on the issues, and diagrams on how to employ relays.

http://www.danielsternlighting.com/tech/relays/relays.html

Andys

my thought on this is to use the current wireing to trigger relays to power the lights. So, when you turn the lights on, the low beam wires turn on the relay (you can use one for both or one for each side). Same with the high beams. You can buy a fuse block from FLAPS and run the necessary power to the fuse block. Run from the fuse block to each relay.

Low beam R wire to Relay applied power
Low beam L wire to Relay applied power
High beam R wire to Relay applied power
High beam L wire to Relay applied power

Battery or Stock fuse block + to fuse block
Fused connection to relay LR,LL,HR,HL constant power
Ground each relay

This would keep the stock switch and High/low relay in play and not require a huge amount of rewire.
If you lift out the tank, you can run the new power along the stock wireing loom and keep it low profile. Mounting the fuse block on the headlight bucket (below the tire cover) makes for easy access.
A GT headlight pop up kit and you can lose another 5 lbs off the front of the car.
Thoughts?

What size wire did you use?
Did you run four new wires???
I understand the relay wiring using the stock setup...got that.
Rich

This is an important point; one that took me a while to figure out (I'm such a rock when it comes to E).

So, if I have this correct, the original power lead goes to terminal 86 on the additional relays?

yup

Sweet. Thanks Jeff.

I didn't use the 100w H4s, I used the 65w, so I just used the stock wiring. There is no need for relays or extra wiring.

However, if you use the 100w bulbs, it seems one wire from the battery to handle 200w would require 10ga wiring.

I'm installing two wires at 12ga. each.

Here's a test that demonstrates how relays can help relieve voltage drop. Different situation I know, but the info is good.

http://www.madelectrical.com/electricaltec...eadlights.shtml

Andys

Great, confuse me now..

So are you using the stock wiring for the low beams and the new wires for the high beams....hmmm

Rich

I had some extra time today so I wanted to tackle this problem. Here's what I did:

Since my low beams are 55W I decided to stay with stock wiring and not touch a thing. I'll run only additional relays and wiring for the 100W high beams. I bought and attached an aftermarket CB Panel in the engine compartment. You see three wires. All 12ga. Left to right is High Beam (HB) left, HB right, and a spare. Should I need to run something from the battery in the future it's nice to have a spare feed already hooked up. The wires go through the bulkhead and under the passenger seat. The third wire is capped off under the seat.

I then ran the wires up the tunnel with the main harness, over the top of the main CB panel and up out to the front trunk. At this point I changed the color of the HB right wire to white.

I made a small aluminum bracket to hold the relay to the headlight motor cover. I pulled 56a from the headlight bracket, fed it back through the opening to the bucket, and attached it to terminal 86. The original power wire (56a) that would turn on the highbeams now powers the relay. The power feed from the battery went to terminal 30. I made a wire to run from terminal 87 to go to the headlamp. And another, the green one, to go to ground from terminal 85.

I showed only the left side but the right is set up exactly the same.

I like using the stock wiring in this way. As mentioned previously in this thread it alleviates a lot of extra wiring and work. Also I have two CB's prior to the headlight. A good safety margin. I haven't tried it out yet since I need the battery to remain out of the car for another repair.

Thanks for the help all!