Headlight relay kit

[Nut Tree]

It was on the 14th or 15th. Whatever Friday night was. It came in the following Thursday, so about 4 business days total. It came packed in a big box so I wasn't sure what it was when it came in. Hopefully, going to get it put in this Sunday.

 

[mu2bdriver]

I just got my relays in this afternoon and sourced all the other parts - including automotive wire - earlier in the week. I need to look at the diagram and get some more under-hood time to get more comfortable with it. 20 degrees and blowing hard doesn't give much motivation. If I have it correct in my mind...

#30 - contact hot side goes to the fuse box and through to the battery
#86 - coil side to ground
#85 - coil side to tie into driver factory wires which continue to dimmer switch
#87 - contact load side to new driver side wires, and
#87A - contact load side to new passenger side wires.

With this in mind, I would be using all 5 of the wires/terminals from the relays, and would be using both the 87 and 87A posts, correct? I'm just not clear as to whether or not I only use #87 for the new wires and splice/solder for either side or use 87 for one and 87A for the other. Because they are internally connected, I hope the latter, but when I tested for continuity earlier, it only 'passed' when leads were connected to 87A/30 and not when 87/30 were connected. I'm thinking that was because there was no power going to the relay.

 

[mjs2011]

I just got my relays in this afternoon and sourced all the other parts - including automotive wire - earlier in the week. I need to look at the diagram and get some more under-hood time to get more comfortable with it. 20 degrees and blowing hard doesn't give much motivation. If I have it correct in my mind...

#30 - contact hot side goes to the fuse box and through to the battery
#86 - coil side to ground
#85 - coil side to tie into driver factory wires which continue to dimmer switch
#87 - contact load side to new driver side wires, and
#87A - contact load side to new passenger side wires.

With this in mind, I would be using all 5 of the wires/terminals from the relays, and would be using both the 87 and 87A posts, correct? I'm just not clear as to whether or not I only use #87 for the new wires and splice/solder for either side or use 87 for one and 87A for the other. Because they are internally connected, I hope the latter, but when I tested for continuity earlier, it only 'passed' when leads were connected to 87A/30 and not when 87/30 were connected. I'm thinking that was because there was no power going to the relay.

I believe you want both headlight wires tied to 87. 87a is on when the relay coil does NOT have power and 87 is on when the relay coil is powered.

I'll see if I can find the diagram, but that is what it looked like to me. So power to the relay turns off power at 87a and turns on power at 87, and vise versa.


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[mu2bdriver]

I believe you want both headlight wires tied to 87. 87a is on when the relay coil does NOT have power and 87 is on when the relay coil is powered.

I'll see if I can find the diagram, but that is what it looked like to me. So power to the relay turns off power at 87a and turns on power at 87, and vise versa.

That would explain why I got continuity between 87A/30 (no power applied/relay in hand) and why I didn't get continuity between 87/30 under the same conditions. If this holds true, does the 87A not have any wire going to it?

 

[mjs2011]

Correct, you won't need to use 87a, and if you have a harness for the relay, you can remove it from the harness too.

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[mu2bdriver]

I finished the relay upgrade earlier this afternoon. About 3 hours total because I was fiddling around and testing the wires after each solder and connection. Putting together the harness was much easier than I thought. Loomed it all together, cleaned it up, and was shocked with how much it improves the brightness. It likely cost me more than the LMC kit but I have 3 extra relays and plenty of extra parts. I really enjoy learning and working on this truck. I didn't take before pictures but here are the afters: low beam and high beam.

 

[79jasper]

Pics aren't showing for me.


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[mu2bdriver]

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[bike-maker]

I printed this image out and threw it in my tool box for a quick reference. Used it many times.
It's for fog lights, but the same concept applies - I usually can't remember where the terminals on the relay should be going...

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Another selling point for the DIY method, If your like me and constantly changing/upgrading things in your truck, you will eventually end up with more relays (I think I have 10 of them now). It's nice to have all of the relays the same, and available at the local parts store.

 

[6.9poweredscout]

So one relay for high beams and one for low beams. Seems simple enough.

 

[drinkypoo]

So one relay for high beams and one for low beams. Seems simple enough.

That is pretty much the whole story. It's best to just understand relays, and then you don't need a diagram. And if you can understand that diagram, then you can understand a relay.

Notably, the diagram includes a fuse. The importance of that fuse cannot be overstated. And we discussed the benefits of having all the relays the same earlier in the thread

 

[eastsideauto]

I've had my LMC kit on the truck for several months now. Love it. Big difference even without any headlight mods. Fit and finish was not the best but it was easier for me to buy a preassembled unit since I have 0000 time to do anything extra.

 

[6.9poweredscout]

yeah I have relays figured out. I make a harness for the starters on the scouts. similar type issue. too small wires from the factory, not enough amp draw to throw the solenoid on the starter. bypass with relay, run 10 gauge. fires up no issues. just have to gather the parts and take the time to do it. don't forget to whip up a parts list guys!