having trouble with my 4 high kit

[MR_CLARK]

Well sorry I don't have a low beam fuse under the hood from what I can see.. I see the high beam but unsure about the low beam

[TritonBoulder47]

Well sorry I don't have a low beam fuse under the hood from what I can see.. I see the high beam but unsure about the low beam

Not fuse, RELAY... You can't do it with fuses... You're truck doesn't have relay's for the headlights...?

[MR_CLARK]

Alright I meant relays.. I don't see a low beam relay unless its labeled under something else.

[TritonBoulder47]

Alright I meant relays.. I don't see a low beam relay unless its labeled under something else.

I'm not sure... I've tried looking for a 98 s-10 fuse panel on-line to look at, but can't find one...

[CodyB]

Well, if it is like my '96 C1500 it doesn't have relays under the hood. They may be under the dash but there is a round plug about one inch big, it is on the drivers side and nearly to the firewall. On mine its got all the power and ground connections for the headlights and turn/park lights, a diode between two connectors could probably make all 4 beams run at once. I have not tried this yet, I'm planning on getting the pair of connectors and add a relay in line without cutting any of my harnesses. Good luck Mr Clark, if yours has this plug I can give you my pin out, or do like I did and just poke around it with a DMM.

[The Performer]

Ok to clear a few things up, here's whats happening with the diode vs relay.

Both do the same exact thing, one just uses an extra relay.

The problem that is being fixed is that most vehicles have a system in which the high beam headlight setting only affects the high beams, meaning when the high beams are activated, the vehicles low beams are no longer switched on.

I have 3 diodes in the pins of my 03 silverado BCM harness plug, that's

DRL's>Fog lights

Fog lights>Low beams

Low beams>High beams

This means, when the truck turns on at night, because of the auto feature the lows turn on, which cause the fog lights to also get a trigger, which cause the DRL's to get a trigger. Whenever Highs are turned on, it causes Lows to turn on, which cause fogs, which cause DRL's. That's what's called the high 8. 8 lights on whenever High beams are triggered, now the reason for the diode is it allows current to flow only one way. Hence being in the day time, the DRL's are on, but cant accidentally feed back to trigger the Fogs on, then on to the lows, then to the highs.

Technically you could tap your wiring from the high beam switch to the low beam switch, however what would happen is whenever you turn your lows on, it would feed to your highs. But that's not what we want, we want our high beams to trigger our lows, and not the other way around. This is where diodes and relays come into play.

The reason this is the same, is that most newer trucks are running off a ground switch system, meaning the relay is getting power to the coil, which is not grounded. Whenever the light switch is activated, it presents a ground to the already positive relay coil, therefore activating the relay to turn on the switch. Technically even older vehicles that use a relay to feed it's headlights, can be triggered in the same sense. Find the two relay switch trigger wires, add a diode that will activate the relay you want to stay on and there you have it.

With even older vehicles, such as my buddies '83 chevy, I had to add the relay. In his truck there are no headlight relays, the headlight switch itself is what went straight from the battery to the headlamp. What happens here, is I find the two feed wires that come from the fuse box/switch for the Low beams and high beams. If you catch the wiring before it splits to the passenger side you will only need one relay, alot of people use 2, (1 for each headlight, but that is unnecessary) decide which of the two wires control what. (Low/High) You will then tap into your low feed with the same gauge wire as the factory (never smaller) because this will be the 12v feed. Now you will connect this to pin 30 or 87 on your relay (we will use 30 for this explanation purpose) then you will run another lead of wire from 87 to a constant 12v source (EX:+ post of the battery) Be sure to fuse this with the same value of fuse as the factory Low beam fuse. (This will be the secondary feed to your low beams, so just think of copying the original run to the low beams)

Now onto the rest of the pins. Use a wire to tap into the High beam wire feed (this wire can be smaller because it will only be used as a trigger for the relay (EX:200ma) Connect this to pin 86 or 85 of the relay (For example purpose we will say 85)

Then from pin 86 you can use a small gauge of wire to run to a suitable ground source. Usually when I install these I use a self tapping screw to mount the relay to a grounded spot of metal under the hood near the driver side headlamp, and using the same screw I attach the ground wire with a ring terminal.

Anyway, I hope this helps, I really wish I had taken some pictures from all the installs I did. I might have another one coming up and Ill be sure to take some good pics.

[TritonBoulder47]

Great explaination Performer...

[MR_CLARK]

sounds like a very good explanation but im not very good at putting words into actually doing it.. i'm a visual learner.. i could probably do it but it would take a while to do

[The Performer]

sounds like a very good explanation but im not very good at putting words into actually doing it.. i'm a visual learner.. i could probably do it but it would take a while to do

I'll try and draw out a diagram real quick for you.

[The Performer]

Heres what I'm describing by adding the relay.