Headlight Relay modification (PICS)

[mfpmax]

First, this thread
http://www.foureyedpride.com/phpBB2/...ghlight=relays
As it contains much of the information needed.

Went to the parts store and purchased 2 40 amp relays(I recommend ordering them from http://www.partsexpress.com as they are much cheaper). Also picked up a 30 amp breaker as well, along with overpriced connectors(all higher amperage connectors were soldered).


The first picture is the voltage while running at idle on the low beam side, the second picture below it is the high beam side. I didn't take readings before I installed the relays unfortunately.



The next two pictures are the low beams.



The next two pictures are the high beams.



And there you have it. If you can solder decently and can read simple schematics, I recommend you do this. If you can't really solder too well, Painless Wiring sells a relay kit that is identical to most of the parts I used except I believe it is ready to wire in...which is REALLY simple. You can either splice into the orignal wiring, or purchase new connectors to go onto the headlights.

[Anonymous]

'bout how long did that take ya?

--Dave.

[mfpmax]

Originally Posted by Daves80Turbo

'bout how long did that take ya?

--Dave.

Shouldn't take long, maybe an hour at most, or two if you're being real picky. Took me longer cause i'm anal, and then it rained a few times.

[joelliott]

nice work there man. Thanks for the picts too, it really helps us understand whats goin on. About the voltages? I have a stock alt and elect system. I have been concerned about it being weak and draining the battery. Althought it hasnt. yet. My sysem runs anywhere from 12.5 V to 14.5 V on normal driving. ei lights, radio, radar detector, etc. If I attempted this mod, would I have to worry about more battery drain? Or is hte voltage difference not that much? Plus, Im a handy guy, but not a mechanic or electrician. Can it be done by a good direction follower? Thanks
Joe E.

[mfpmax]

I personally haven't a clue about the drain as of yet, but I have the same concerns as you. I would assume with a stock system, and the normal drain(IE no fancy high power aftermarket stereo), it should be okay, but I'd recommend a alternator upgrade anyway, i've been looking at doing one forever myself.

As for doing it, I would think so, following the diagrahm that Mike Choke has in the the link at the top of the thread, it should be simple, only need to find the correct wiring and splice into it correctly.

[BetterDays]

Originally Posted by mfpmax

... but I'd recommend a alternator upgrade anyway, i've been looking at doing one forever myself.

Summit - Powermaster 140AMP one wire.... Yea!

[Matt82GT]

Originally Posted by mfpmax

I personally haven't a clue about the drain as of yet, but I have the same concerns as you. I would assume with a stock system, and the normal drain(IE no fancy high power aftermarket stereo), it should be okay, but I'd recommend a alternator upgrade anyway, i've been looking at doing one forever myself.

As for doing it, I would think so, following the diagrahm that Mike Choke has in the the link at the top of the thread, it should be simple, only need to find the correct wiring and splice into it correctly.

[mfpmax]

What huh...nothing...

[Matt82GT]

Originally Posted by mfpmax

What huh...nothing...

in english please.

[mcb82gt]

I have to bring this old thread up, the link with the info is a dead horse.

[Mike Croke]

Here is how I did mine:


This guy did a more thorough job of documenting:
http://vb.foureyedpride.com/showthre...ghlight=relays

[mfpmax]

He also has a fancy smancy box

[mcb82gt]

Are relays all different? On the relay wiring, Daniel Stern's lighting site has
http://www.danielsternlighting.com/t...ys/relays.html

85 ground
86 multi switch input
30 starter solenoid
87 headlights

It said you can get a relay with two 87 terminals, run one to left and one to right side.

[FoxChassis]

Yeah, not sure what's going on with Croke's diagram but the terminal configuration at Stern's 'site is correct.

If you want a mini 40A SPST relay w/ dual "87" outputs, here are the Hella part numbers:

87453 - w/ bracket, w/ diode
87452 - w/o bracket, w/ diode
87118 - w/ bracket, w/o diode or resistor
87483 - w/o bracket, w/o diode or resistor

"87a" is NOT a second "87" terminal.

[mfpmax]

I had no problems with Croke's diagram.

[mcb82gt]

Do I need the relay with or without diode/resistor? What is the function of it in this application? Sorry for my electrical ignorance.

[93-331-29PSI]

My wiring was done exactly like the one on Daniel Stern's site and I had no problems.

[FoxChassis]

Originally Posted by mcb82gt

Do I need the relay with or without diode/resistor? What is the function of it in this application?

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

Eliminating voltage spikes:

Voltage spikes from 300V to 500V can occur momentarily when a relay is switched off. Sensitive electronic equipment can be damaged or malfunctions can occur if these spikes reach the vehicle electrical network without suppression. A relay with a resistor reduces these voltage spikes to less than 100 Volts. A relay with a diode eliminates them completely. The correct polarity of the connections is marked on the diode protected relay.

[ujslost]

Ok since I am new to the 4 eyes. Please explain this to me like Im a 2 year old. Why are you guys doing this mod?

[FoxChassis]

mcb82gt posted this link:

http://www.danielsternlighting.com/t...ys/relays.html

You should read that page.

[ujslost]

Ok I read some of that just now and skimmed over some of it just to get an idea of whats going on.

Could this fix the problem i recently encountered? I was doing some work on my car. I had left the headlights on without the engine runnin. Next i smell a burning wire smell. i pull the headlight switch connector off the switch and find this.

[FoxChassis]

That probably happened because the terminals were old, corrorded, dirty, or all three. Any or all will increase resistance. Then the wires and connectors heat up, creating more resistance. Add to all of that the draw of the headlamps and it heats everything up even more. Eventually you get what you got....burnt connectors, wires, terminals, or worse yet, an electrical fire that could cause some real damage (to the vehicle and or you).

Replace the headlamp switch, that connector, and any of the damaged wiring and terminals, then set up a relay circuit for the headlamps. You shouldn't have any more problems with that headlamp circuit, AND the headlamps will be brighter than if they were just running through the factory circuits.

If you eventually want to replace the sealed-beam headlamps with an H4/H1 conversion 'kit', the wiring will already be done and the conversion will just be plug-n-play.

[ujslost]

ok so just replace that connector, then do this mod? Thanks.


anyone got one of these headlight switch connectors they want to donate to the hope my car dont catch a fire charity? (especially while i got my beautiful daughter in ther with me)

[FoxChassis]

You should be able to get that connector, with about a six inches of new wiring, at any auto parts store.

[ujslost]

oh, well ok.
ford headlight harnesses were notorious for burning up , i had a 94 ranger that did I had to replace the harness connector at the bulbs