The low beams stay on with the highs the way it is now...they shouldn't but they do lol. It has to be the bulbs. I spaced it before but that actually makes the total draw 310w with the high beams on. Still have almost 1000w of room before the cable reaches capacity though lol.

To measure voltage drop accurately, you have to take the reading at the bulb while it's on and compare it to the battery voltage. I didn't measure mine since I was upgrading the wiring for high-watt bulbs anyway.

 

NICE HARNESS!
2 questions:
1) did you fuse the headlight power in any way?
2) did you crimp connections or solder them?

 

I tried using one relay (like the diagram) for low and one for high beam and it resulted in both being on for high beam. Wouldn't have noticed but checked the amp draw. I got it to work by using the two relays in a series. Each lamp draws about 5+/- amps on low or high. mine is a '98, maybe older ones are different but it sounds the same.

 

Got any pics of the harness wired into the truck? I cant figure out how it plugs in, do you still keep the original harness? When you said you ran a dedicated ground what did you mean?

 

No pics of it installed...the relays are mounted by the battery and it runs along the radiator support to the driver's side headlight. By dedicated ground I mean I ran a ground wire (not pictured) from both headlights all the way back to the battery instead of grounding them to the body.

 

Cool! Thanks, that makes sense now.

Just one more quick question; the end that goes to the factory H4 connector only hooks up to ONE of the original H4 connectors right?

 

Right.

 

Allright thanks! Ill be ordering parts tonight; my headlights suck big time.

 

A good explanation is here:

http://www.4crawler.com/4x4/CheapTri...#WiringHarness

 

Just a quick question. Where do you get your H4 pigtails from? Is there a place that sells them locally or do you have to order them online?

 

I got mine at either an autozone or a local auto parts store.

 

Alright ill have to check them out. I just ordered my housing for my H4 upgrade and plan to upgrade the harness at the same time.
Thanks for the super quick reply

 

I found some on ebay but theyre already prewired with either 16 or 14 gauge wire. I want 10 gauge!! Anybody know a source for those or just the connectors by themselves so i can wire 10 gauge throughout?

 

Don't know that you will ever find what you're asking for: NOBODY'S H4 or sealed beam is gonna draw anywhere near enough power to need 10awg at the headlight connector.
BUT if you want to go that far over the top you could use the original (or an aftermarket) connector with 14awg, cut off all but the last inch before the connector, strip off all the insulation and solder 10awg to the crimp part of the connector and the 1" on wire then heat shrink it.
however, IMHO (27years of aircraft/heavy truck/automotive wiring) if you have good connections at the light there is not a bulb on the planet that would cause issues with the 12"-18" 14awg pigtail coming off the headlight connector. you are not going to get any "bottle-neck" effect on your amperage running 100 or even 150 watts of 13.5vdc through a 14awg wire (which is rated at 15amps max or 202.5watts @13.5vdc over a 100' length).

 

I used some 12ga and it was a bit too stiff and bulky and I think silly overkill. I think it is more the run needs to be short and the connections need to be clean. Regular high or low beam only draws 9.5 amp or so.

 

How many of the positive wires do you have connecting to the battery? Is it just one that splits off into the two relays or did you run a separate wire for each relay?

 

I ran one wire from the battery, through a fuse block, to the relays (it splits at the relays and feeds both). Its 12AWG. total length is only about 2.5'

 

If you're going to run hi/lo together as your high beams, each relay should have its own 12awg wire to the battery (assuming everything else is 12awg).

If you have one wire feeding both relays (again, assuming everything is the same gauge) and both relays are drawing power, the total draw effectively doubles for that section of wire in relation to the rest of the harness (downstream from the relays). This will cut the entire wiring harness' capacity in half. It will still work this way, but why build it half ass.

Also, I didn't illustrate this in my schematic, and I don't think I mentioned it anywhere, but my power wires are fused. Anything connected to the positive terminal of the battery should always be fused as close to the battery as possible.

 

Not sure that I like my approach to wiring this harness being called half assed (I stopped doing half assed wiring back in 1984 when I went to school in the Navy to learn how to wire properly).
After figuring the appropriate wire size, taking LENGTH in to consideration, I feel very comfortable that 12AWG is more than sufficient to power this unit at full power.
12AWG is rated at 20amps @ 12VDC at 100' of length. Being that mine is only 2.5' long we are in good shape.
If you were to put your theory into practice your wires from the relays to the headlights would have to be equal in length (i'm guessing they arent) or one headlight would be brighter than the other!
Thanks for the vote if confidence.......

 

Ok, thanks for the explanation. 12AWG is more than sufficient for my application and not to mention it is also cheaper than the 10. While we're on the topic of wiring which would be better: tinned or regular primary wire? I found a source for both with good prices and am just wondering if the tinned wire provides any advantage over regular wire.