H4 headlight relay question Options

[SKL1]

Putting in new H4 headlights with the 100W high beam and utilizing the "relay" to protect the OEM wiring.
Using the relay and new lights from Pelican and have checked and rechecked my wiring several times. Fused power from battery to #30. #85 to ground. #87 to high beam terminal of each light, #86 to old headlight wiring on one side, and taped off the other as recommended.

I have 12V into relay when high beams are on, and good 12V from battery, but neither high beam works thru the system, though low beams work. Fuses all good- new JWest fuse panel. Bulbs new and work fine when bench tested.

Any ideas???? Have 2 new relays from Pelican and have tried both...

('73 2.0)

[Dave_Darling]

You don't have to have relays for the low beam if you keep to the stock wattage of low beam. It's not a bad idea to have one, mind you, but it's not necessary per se.

If you have a relay that is able to handle the current for both lights, you can use only one relay for the high beam of both. You'll want to have a wire from the #87 terminal of the relay to the power connection on each light. (And another relay for the low beam of both if you go that way.)

The four-relay setup above is the best setup (offloads almost all the headlight current from the ignition switch and the headlight switch) but is the most complex.

Clay's point about the grounds for each light is a good one. The ground wires should be at least as thick as the power wires, and they should connect snugly to a solid part of the chassis!


Troubleshooting your current setup:
- Do you definitely have ground at pin #86 on the relay?
- When you trigger the high beams, do you actually have +12V (hopefully more like 14V!) at pin #85 of the relay?
- Do you have power at #30 of the relay?
- Do you see +12V at pin #87 when the high beams should be on?
- Can you jumper straight from #30 to #87 (use a nice thick wire!!) to get the high beams on?

--DD