H4 Wiring Problem!!! Please Help!
Thread Starter
Junior Member
Joined: Apr 2008
Posts: 19
Likes: 0
From: Virginia
Car: 1991 Chevy Camaro Z28
Engine: 5.7L TPIS Miniram
Transmission: 700R4
Axle/Gears: 3.73 Eaton Posi
H4 Wiring Problem!!! Please Help!
So to start off, I installed H4s in my third gen with the painless wiring harness. I had no problem hooking them up or getting them installed. Everything seemed to be going great. The low beams came on, and then the high beams. However, when I switched them back to low beams that's when it went funky.
The low beams worked the way they were supposed to, but the high beams remained lit. I checked voltage going from the Headlight switch to the dimmer, and I'm getting 12 volts. However, I am getting 4.7 volts from the high beam power (LT GRN) with the low beams on. I tried replacing the dimmer... Same results. I get the same readings regardless of whether the relay circuit to the headlights is plugged up or not.
. So I concluded that I am not receiving feedback voltage from the relays. The only thing I have not checked is the fog lamp circuit. I am about pulling my hair out on this one! Help please!!!
The low beams worked the way they were supposed to, but the high beams remained lit. I checked voltage going from the Headlight switch to the dimmer, and I'm getting 12 volts. However, I am getting 4.7 volts from the high beam power (LT GRN) with the low beams on. I tried replacing the dimmer... Same results. I get the same readings regardless of whether the relay circuit to the headlights is plugged up or not.
. So I concluded that I am not receiving feedback voltage from the relays. The only thing I have not checked is the fog lamp circuit. I am about pulling my hair out on this one! Help please!!! Thread Starter
Junior Member
Joined: Apr 2008
Posts: 19
Likes: 0
From: Virginia
Car: 1991 Chevy Camaro Z28
Engine: 5.7L TPIS Miniram
Transmission: 700R4
Axle/Gears: 3.73 Eaton Posi
Re: H4 Wiring Problem!!! Please Help!
Well, It happened to be the only thing I didn't check... The fog lamp relay! I just unplugged it, and everything works fine now. I guess I was getting power to the headlight relay through the fog lamp relay. Problem solved!
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