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Doin' the headlight relay thing...

bear76 said:
I just searched for more info. But one post, which was excelent BTW, said to pull power from the alternator and run another cable from the alt to the battery? I figured you could just run directly from the battery for power, is this wrong?
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So link the post
 
bear76 said:
I just searched for more info. But one post, which was excelent BTW, said to pull power from the alternator and run another cable from the alt to the battery? I figured you could just run directly from the battery for power, is this wrong?
Click to expand...

You can run power from the alt output, the battery or the junction block. It's all pretty much the same.
The alt output will have the highest voltage (in a properly working system) but keep in mind that the higher the voltage, the shorter the bulb life.
 
I hadn't seen any evident fuse holders in the LMC photo either, and had assumned it didn't have them. Fuse protection is a must, so plan on adding weatherproof inline fuse holders to the LMC harness, and thanks to ZooMad75 for the heads-up. Of all the places to go cheap and cut a corner, why they decided to do it there is beyond me.

In any case, it'll be interesting to see how much voltage and light output I gain at the headlamp sockets just by installing the harness (with added fuse protection, of course) and using the stock sealed-beam halogens.

That 4-light kit looks like the winner to me. After I get the harness installed and see the difference with the stock sealed-beams, I'll grab that 4-light H4/H1 kit and throw those in. I had been looking for something like that, but all I'd fouind thus far were junky, cheap (er, "inexpensive") lights with totally clear or "diamond-cut" ricer-type lenses that focus light poorly and blind oncoming drivers (but no doubt came with some neon, a big window sticker and a huge fart can muffler), so thanks to k20 as well for that link to some good headlights.
 
Not having looked at the wiring on a first gen, I still don't see why the same idea won't work. Those trucks used similar wiring in that all the power is run through the cab to the switches and then back out to the lights. Meaning, prone to high voltage drop. Relays will work, you just need to verfiy the wiring before you get to working on it.

Keep in mind Painless Wiring has had a generic kit out for years to do the same thing. I first read about it in HOT ROD magazine a few years back. You will pay painless prices though.

In any event, adding a relay to eliminate the stock wiring/voltage drop will improve light output. I'm going to do this same thing to my 69 nova and it is setup almost identical to how my K5 was.
 
that's awesome, I'll end up doing it soon probably. I was thinking it was similar. I'll check out painless, but I don't want to pay their prices
 
O and for the 89-91 guys, http://www.rallylights.com/hella/150mm.asp It only shows them having H4 bulbs though, Im not sure how your headlights work, if all 4 are always on or not. If they are then I guess you would need 2 kits, as a kit appears to only be 2 bulbs.

If its only 2 on with low-beams or 4 on with high-beams (like the over/under 4 headlight trucks), then I guess you could replace the H4 bulbs with H1's.
 
dremu said:
Anyway, was wondering if any of y'all had done anything scientific, photos or anything, to compare the before-and-after of the relay upgrade, besides just checking voltage. I think that means about 10-15% more power at the bulb, which is cool for the low-buck nature of the project.
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NOthing scienttific but when I did this to a lil car I used to drive I used 10 guage wire from battery to relay to light. The Rangers in the National park I used to work in were always pulling me over for misadjusted headlited or leaving high beams on. I'd flick highs on and hand em the slip from a garage saying they were adjusted. I think I also swapped in GE halagen plus lights. Made a HUge Difference

On that car the low beams cut out when high beams cut in leaving a dark spot in front of the car which irritated me so somehow I tied in a third relay to rectify that situation also. hm that is still sitting on top of the hill at my folks house might have ot go revisit that idea and work it into the 73
 
LMC harness

I received the LMC harness, and as they assured me, the lower-priced of the two available part numbers is indeed for a four-headlight system.

Just a few impressons: Other than having no fuse protection in the hot leads (which is easily added with a pair of weatherproof inline fuse holders), the wiring is OK, more than adequate gauge for a 30 amp 12VDC circuit.

The quality of the connectors could be better. They aren't weatherproofed at all, but neither was much underhood wiring back in 1985. Since I'm going to be adding weatherproof inline fuse holders, I'm tempted to modify the harness with weatherproof connectors in several spots before I install it.

I think that I'll also get a weatherproof relay block and a pair of name-brand 30A relays to replace the generic 30A relays and the easily-drenched connectors that mate with them.

The headlight connectors for the sealed beam lights aren't weatherproofed either, but that'd be about impossible to do with the way the prongs stick out of the back of the sealed beams. In this instance, I'll just use what't there until the Hella H4 and H1 lights get installed, and at that point, I'll yank these prehistoric connectors and replace them with something better (rather that just stick those short adapter cables on the end).

All in all, I'm satisfied with paying 20 bucks for a neatly arranged set of wires of the correct colors, gauge, and length. Connector type and quality could have been better, but when you only drop 20 bucks, you can't be too picky!
 
I've not looked at the kits yall are talking about but when I did mine I pulld power to the relay from the original light circut, therefor it was fuse protected from the OEM fuse/fuseblock. I did add circut breakers inline to the headlights though
 
If you want some really nice weatherproof connectors, poke around under the hood of a n early 90's Buick or Caddy at the junkyard. They have a rack of relays mounted on the firewall, complete with WeatherPack connectors. :) I take as much of the wiring harness as I can get, to go with the relays. They work awesome for controlling lights. You can see a pic of what I'm talking about near the bottom of this page: http://www.angelfire.com/super/ThunderTruck/tech_articles/Light_Install.htm
 
HarryH3 said:
If you want some really nice weatherproof connectors, poke around under the hood of a n early 90's Buick or Caddy at the junkyard. They have a rack of relays mounted on the firewall, complete with WeatherPack connectors. :) I take as much of the wiring harness as I can get, to go with the relays. They work awesome for controlling lights. You can see a pic of what I'm talking about near the bottom of this page: http://www.angelfire.com/super/ThunderTruck/tech_articles/Light_Install.htm
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Your tips are much appreciated. That big relay block would give me lots of expansion room for fog and driving lights, and other such accessories. I know that the OEM wiring components on an '85 Chevy truck aren't anything to write home about in the splash-proof department, so I just might start replacing connectors here and there, one at a time, all over the truck.
 
HarryH3 said:
If you want some really nice weatherproof connectors, poke around under the hood of a n early 90's Buick or Caddy at the junkyard. They have a rack of relays mounted on the firewall, complete with WeatherPack connectors. :) I take as much of the wiring harness as I can get, to go with the relays. They work awesome for controlling lights. You can see a pic of what I'm talking about near the bottom of this page: http://www.angelfire.com/super/ThunderTruck/tech_articles/Light_Install.htm
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Yea, junkyards; whatever fits in the pockets. Trim screws, clips, fuses, bulbs, OEM nuts and bolts. $2 cover charge.:D
 
Ok, as a followup, I installed the LMC HD harness this weekend, and the H1/H4 kit, with hella e-codes and 55/65 bulbs (what came with the kit).

WOW! What a difference. My low beams now, are better than my high beams before. My high beams now are better than my old highbeams & driving lights. And now I can aim my driving lights to get some light down the road instead of illuminating nearer the truck.

What a difference. Money WELL spent. The bulbs arent any high zoot xenon or blue lights, just the ones that come with the kit and the light is much whiter than the old ones.
 
k20 said:
Ok, as a followup, I installed the LMC HD harness this weekend, and the H1/H4 kit, with hella e-codes and 55/65 bulbs (what came with the kit).

WOW! What a difference. My low beams now, are better than my high beams before. My high beams now are better than my old highbeams & driving lights. And now I can aim my driving lights to get some light down the road instead of illuminating nearer the truck.

What a difference. Money WELL spent. The bulbs arent any high zoot xenon or blue lights, just the ones that come with the kit and the light is much whiter than the old ones.
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So, when you have the high beams on, all 4 lamps stay lit?
 
k20 said:
Ok, as a followup, I installed the LMC HD harness this weekend, and the H1/H4 kit, with hella e-codes and 55/65 bulbs (what came with the kit).

WOW! What a difference. My low beams now, are better than my high beams before. My high beams now are better than my old highbeams & driving lights. And now I can aim my driving lights to get some light down the road instead of illuminating nearer the truck.

What a difference. Money WELL spent. The bulbs arent any high zoot xenon or blue lights, just the ones that come with the kit and the light is much whiter than the old ones.
Click to expand...

I'd love to see a pic of the lights in the frontend now.. I know they look like headlights, but Im sure the reflector is different..
 
Yeh all 4 lights are lit like factory.

For a pic, look in my webshots. Ill try to take a pic tonight.
 
After that enthusiatic review of the 4-lamp 165mm Hella H4/H1 kit by k20, I went ahead and ordered one. I slow-boated it, so it'll be a week or so. Might as well do the harness upgrade and headlamp upgrades at the same time.
 
where can ya get just two of the relays and what amperage rating do they need to be

does auto zone or napa or o reilly auto parts have any that would work ?

this would be real simple to do with just a coupel relays and a roll of 12 gage wire

cake walk

and also add larger ground to them

i would jut use stock halogen bulbs and this upgrade and wow, would be crazy bright

no need to spend 100 bones on some wierd bulbs



thanks
 
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