Thread: Headlight Wiring UPGRADE - Advice Needed....

I was going to post this in the Technical Chatter section but realised I don't have access to post in that section for some reason.....

Anyways, hopefully, someone here may be able to help.....

On the PUMA I bought last I've been having intermittent issues with the headlights. Upon tracing out the wiring as much as I could I've realised the previous owner had someone do a headlight wiring upgrade on the car. The problem being is where the relays were mounted had caused water to enter and start corroding the Terminals causing one of the 3 relays to fail. I traced out which relay failed and just replaced it BUT I really NEED to replace all Relays along with the relay bases to ensure no future issues.


The problem is after tracing out (as much as I can) the wiring diagram I cannot see or understand why the person installed 3 relays and not just 2 relays. The way it is wired (see attached diagram), it has a relay for HIGH beam and a relay for LOW beam and a 3rd relay that basically switches the LOW beam relay on & then disconnects the LOW beam relay when the HIGH beam relay is turned on.


Can anyone see an issue with me getting rid of the 3rd relay (Relay-C in the diagram) and just use the HIGH and LOW supplies from the inside the cars Headlight Switch/Fuseblock to switch the LOW and HIGH relays accordingly?


I've attached a diagram with Relay-A being the LOW beam relay and Relay-B being the HIGH beam relay. Each Relay is marked with terminals 1 to 4 accordingly and what voltage (if any) is at those terminals depending on the headlight switch position with engine running.

Originally Posted by Dorian

Rob,
I've just put in a traxide system and found it top notch, lots of info, all the bits you will need comes with it and it pretty easy to install. Vast improvement to the headlight brightness and it takes the load off the indicator Hi\Lo beam switch.
Looking at your drawing, it looks like someone has changed the headlights from positive switching to negative switching, so you may have a few experiences putting in any system designed for the original wiring.
In answer to your question, if you take the red/green wire from C1 and put it onto A2 (removing the existing wire from C3a to A2) this should give you what you want. If your Hi/Lo beam switch is working correctly then Lo beam should be off when Hi beam is on. If I had to guess the relay C was put in because of a fault in the existing column hi/lo switch.

Cheers Glen.

Yeah, down the track I might look at the Traxide system but from what I've worked out, I can simply replace 2 of the old relays (A& and bases and get rid of the 3rd Relay (c) and simply use the feed from Relay-C to activate Relay-A and job is done. Everything else is fine for the moment so I'll put the Traxide system on the future To-Do list.

The way the person has wired it (using negative switching) is fine from what I've worked out and for the moment I'm happy to leave it as it is...

I just wanted to make sure that there wouldn't be a problem if I got rid of the 3rd Relay (C) and from I can see, there shouldn't be....