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I am getting ready to install relays for the headlights in my 74. I have 2 green wires and two brown wires. Would it be best to use four relays or should I combine the greens and the browns into 2 relays. Or, is there a better combination? Thanks.
Here's a really clean way to do it- less wires spliced by using a Bosch "Fog light" relay-
It has two switched output terminasl rather than the common relay with one.NC and the other one NO
0 332 019 150
Summit Racing has them for $4- made in Portugal- and MUCH better than the Chinese junk out there
Harness- simple and clean!!!
I like the Delphi waterproof fuse holder-the wire is SXL rated for 256º- the standard primary wire is only rated at 180º- use the good stuff- having reliable headlights are important!!!
i use a male connector- so you don't have to cut up the harness
And for the connection- there's two types- the gray works on the fiberoptics- not needed on your 74
While that sounds interesting, your wiring schematic is a lot less than complete.
Also, wiring in 2 Bosch relays mounted on the left inner fender is really straight forward and easy.
While that sounds interesting, your wiring schematic is a lot less than complete.
Also, wiring in 2 Bosch relays mounted on the left inner fender is really straight forward and easy.
I just did this and I believe there's only one brown wire, not two. At least on my '75. I did have a hell of a time determining which wire was the "real" brown wire, though, as the pink seemed to have faded to brown over time.
I just did this and I believe there's only one brown wire, not two. At least on my '75. I did have a hell of a time determining which wire was the "real" brown wire, though, as the pink seemed to have faded to brown over time.
Yes- one tan (not really brown) wire for the low beams -spliced at the low beam connector
Below is a cleaned up factory harness- and how sketchy the grounding was done by the factory!!!
Richard, when I first looked at this, I thought, thats not even the same setup. I'm looking at this on my phone. Then I blew up your first diagram. Ahhhh. This is for people that want a plug and play system all mounted up in the nose I would assume.
Not for people willing to open up the harness on the left inner fender and install 2 Bosch relays the old fashioned way. (Read, tight ***).
However, this method will still mean running fused battery power to the relays, which are now even farther from the source. Still, for those that don't wish to unwrap a harness or perhaps can't properly solder a wire. ......
I guess, not for me. But perhaps for many.
Yet I see an awful lot of headlight relays on the inner fenders on all sorts of older cars at the car shows.
Very clean. Very tidy.
Richard, when I first looked at this, I thought, thats not even the same setup. I'm looking at this on my phone. Then I blew up your first diagram. Ahhhh. This is for people that want a plug and play system all mounted up in the nose I would assume.
Not for people willing to open up the harness on the left inner fender and install 2 Bosch relays the old fashioned way. (Read, tight ***).
However, this method will still mean running fused battery power to the relays, which are now even farther from the source. Still, for those that don't wish to unwrap a harness or perhaps can't properly solder a wire. ......
I guess, not for me. But perhaps for many.
Yet I see an awful lot of headlight relays on the inner fenders on all sorts of older cars at the car shows.
Very clean. Very tidy.
I get where you are coming from- but the connectors and wire are 50 years old- time to replace and do it right!
I made mine really tidy- placed the relays up under the front-
Why not save all that trouble and buy a 4 headlight relay system from Octane Lighting for $40. Works like a charm. 2 relay system with ceramic headlight connectors.
Why not save all that trouble and buy a 4 headlight relay system from Octane Lighting for $40. Works like a charm. 2 relay system with ceramic headlight connectors.
Hmmm- I just read the reviews-
Last edited by Richard454; Jan 9, 2024 at 10:59 PM.
Headlight Relay Wiring
