electrical guys help (headlight problem)

OonDeanisS · Feb 7, 2004

i got the H4 headlight conversion, but it didnt come with wiring harnesses for the high beams, which now have 3 prongs and used to have 2.

Can someone explain how to get a 3 prong(low beam) wiring harness to wire up to the high beam wires? as of right now, my drivers side high beam wiring harness has 2 wires, and the pass. side has 3, and both the low beams have 3.

I know i need to buy new wiring harnesses, but can i just split the wires off the old one onto the new one so power goes to both? Then what would i have to do with the old highbeam wires?

OonDeanisS · Feb 7, 2004

ttt if anyone has even an idea please post it

Paully's5.0 · Feb 7, 2004

Haven't done the swap, but your best bet is to get a hold of a wireing diagram for the car and one for your new headlights. From there you should be able to figure out where you can get your power from.

HISSIN50 · Feb 7, 2004

OonDeanisS said:
i got the H4 headlight conversion, but it didnt come with wiring harnesses for the high beams, which now have 3 prongs and used to have 2.

Can someone explain how to get a 3 prong(low beam) wiring harness to wire up to the high beam wires? as of right now, my drivers side high beam wiring harness has 2 wires, and the pass. side has 3, and both the low beams have 3.

I know i need to buy new wiring harnesses, but can i just split the wires off the old one onto the new one so power goes to both? Then what would i have to do with the old highbeam wires?

i think i get the idea of all this. the four eyed wiring had two wires per beam (4 per side), and now you have 3 wires total (per side).
as i recall, the three wires (on 87-93 cars) are: one for ground, one for lows, one for highs.
yours are: one is ground, one is beam, X4.

on each side, i would forget about the ground on one of the beams (i.e., highs). run the hot wire from the high beam to the high beam wire (or connector) for the H4's. make sense? low is still low, ground is still ground, and high wire is moved to the new connector.

this makes sense to me. as for colors, check schematics. i think this is what you are getting at (im not familiar with 4 eyed pride stuff). if im off target, my bad. good luck.

OonDeanisS · Feb 9, 2004

whoa i dont get that, but ill reread it when i get home and try to make sense of it.
I now have 6 wires on the pass. side and 5 on the drivers side total.

HISSIN50 · Feb 9, 2004

i just re-read and i see what you mean. i have no idea why it is like that. i would check schematics (4 eyes) vs the schematics for the 87 on up. or maybe Mustang 5L5 will chime in. im sure he knows (or TMoss and the other, ahem, old timers).

OonDeanisS · Feb 10, 2004

does anyone know what each prong on the bulb is for?

OonDeanisS · Feb 11, 2004

OonDeanisS · Feb 12, 2004

ok i figured out how to wire them up today, but now my high beams are on all the time and i have no idea why. All i changed was i took out the 4 old sealed beams, and put in the 2 H4s on my low beams, and now the high beams have constant power. They are not even as bright as the lows though until i put on the highs and they get REALLY bright. (12V 80W/100W bulbs)

OonDeanisS · Feb 12, 2004

they're all in and working, but are also grounding somewhere so they blink and dim and turn off for a second then come back on while driving(really really annoying) but i think i may have fixed that, im not sure yet until i drive it. They look great though! ill post pics when i can get to a digital camera

OonDeanisS · Feb 12, 2004

i feel like im talking to myself here lol

HISSIN50 · Feb 12, 2004

i really dont get what you did, but i just warn that if you have not updated your wiring (and alternator output), you may find trouble soon (perhaps the flickering you refer to).
assuming you have two H4's total now, running 80/100 beams, that is ~13 amps on lows, 17 on highs, and 30 if you wired lows to stay on with highs (or cant get highs off).
you may have this all figured, but it was worth mentioning in case.

glad to hear you like it and that it works well.

tmoss · Feb 13, 2004

Very good point about the wiring now being too small - over heating and failures may occur. It's best to run high wattage lights through a relay from the battery.

OonDeanisS · Feb 13, 2004

i now have 4 H4s, and they are all on all the time, but only 2 are bright at a time. i think they are just grounding somewhere. Can you explain that relay thing?

tmoss · Feb 13, 2004

Buy a good 30-50 amp relay to power up the lights and an inline fuse from the auto parts store. A relay is the same thing that powers your fuel pump. You run 12v power from the starter relay on the driver's fender, run it through an inline fuse and then through the power contacts of the relay to the lights. Then you run a 12v power source from the light switch to the coil of the relay, which closes the relay switch and applies power to the lights.

HISSIN50 · Feb 13, 2004

Tom's advice is right on

i run relays on low, high and fogs (albeit with two H4's total).
i chose to put the relay in the engine bay. makes wiring easy. i found the correct wire in the harness (you already have the wires known and located). i will lay this out since it sounds like you arent real familiar with relays (just a breakdown of what Tom said).

using a standard Bosch style SPDT relay:
the side of the wire that comes from the headlight switch (that went from the headlight switch to the light) goes to terminal 86,
other side of that wire (that goes to the given bulb) is terminal 87
fused battery power to terminal 30,
ground to 85,
87A not used.

Bosch type SPDT relays are good for 30 amps usually. 85 and 86 are coils (used to switch the relay on. you need one to be positive and one neg.). when energized (both pos and neg are present), they allow terminal 30 to flow to 87. does this make sense? sound good to you Tom?

tmoss · Feb 14, 2004

Sounds good - I'd post a colored diagram here but Stangnet has chosen not to correct the problem they have - when you attach a picture file to a thread it does not appear in the post. REALLY SUCKS - this "upgrade" has been VERY problematic for Stangnet - it's not the site it used to be and now holds no edge over Corral like it did before.

jerry beach · Feb 14, 2004

tmoss said:
Sounds good - I'd post a colored diagram here but Stangnet has chosen not to correct the problem they have - when you attach a picture file to a thread it does not appear in the post. REALLY SUCKS - this "upgrade" has been VERY problematic for Stangnet - it's not the site it used to be and now holds no edge over Corral like it did before.

I agree with you Tom. I gotta get a host now and learn to insert images in the text now. I know it is quite simple, but I have tried it and it doesnt work.

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