Headlamp Relay Conversion

Steve · Post by **Steve** » Wed Dec 12, 12 9:47 am

Been doing some digging on a topic that Blue mentioned to me a while ago and am starting to plan it for the spring.

Following the MAD conversion, Blue suggested changing the lighting circuit to a relay operated system to take most of the power for them out of the light switch/ dash and into the engine bay....effectively just using the switch to trigger the relay using a very small current instead of having the full lighting current going through the switch.

Through a recommendation from someone who has completed this upgrade, I found this guide...

http://www.dieseltruckresource.com/dev/ ... p?t=176263

Blue has kindly linked me to the following sites aswell...

http://www.danielsternlighting.com/tech ... elays.html

http://www.vehicle-wiring-products.eu/V ... mepage.php

Still in the Winter planning stage but anyone got any thoughts on this......maybe any tips for a complete amateur like me please?

Cheers Steve

Adrian Worman · Post by **Adrian Worman** » Wed Dec 12, 12 10:20 am

Yeah go on Daves challenger message board where you'll find a link to it from moparts or something similar. It's well easy tho Steve, much easier than yer ign mods you've just done.
Get the relays from one of the auto electric suppliers on the web, there's one a lot on here use but I can't remember the name, they do universal relay kits with everything you'll need and detailed instructions.
Go on Steve ............ you know you want to

Steve · Post by **Steve** » Wed Dec 12, 12 10:32 am

Thanks Ade, will have a look at that definately. Blue put me on to a good site for electrical bits n bobs, Ive ordered a catalogue from them,

Cheers Steve

ANTON · Post by **ANTON** » Wed Dec 12, 12 10:45 am

ive done this conversion and put halogen lamps in and built a whole new harness so that all four lights work in dip and main beam. the relay conversion and new halogen lights made a great difference.
check my thread for what i did

Steve · Post by **Steve** » Wed Dec 12, 12 12:08 pm

Thats great Anton, thanks will dig it out...

Cheers Steve

Matt · Post by **Matt** » Wed Dec 12, 12 12:20 pm

suppliers I can recommend :

carbuildersolutions.com - owned and run by a guy I've known for years.

vehiclewiringproducts.co.uk - use them all the time at work.

MrNorm · Post by **MrNorm** » Wed Dec 12, 12 12:28 pm

Yes, very worthwhile mod, look at the maths and you'd be surprised what % of light output you are losing for a small voltage drop. Eberg from Mopar Action has been a long-standing advocate of this as well......

Did this a while back.

adrianp · Post by **adrianp** » Wed Dec 12, 12 10:50 pm

This is pretty simple to do and I'm 1/2 way through a conversion myself. The Daniel Stern lighting link you've got is a great start, it helped me heaps. I found the following useful to:

http://www.midnightdsigns.com/james/headlights.htm

It's not Mopar specific but I don't really think it needs to be for what you need to do.

Also +1 on http://www.vehicle-wiring-products.eu.

adrian.

Steve · Post by **Steve** » Wed Dec 12, 12 11:30 pm

Thanks Adrian,

Will study that in detail! Out of interest, exactly what wire are you using (AWG still does my head as I never know for sure if 2mm is diameter or squared when I read the label). Exactly which light sockets are you using?? Im looking for un-insulated butt connectors etc but cant find the correct ones over here..... Did you use the Bosch relays listed....have you had to deal with twin headlamps and a foot dimmer switch?

Sorry loads of questions but Im keen to do this once and properly and your advice will be invaluable!

Cheers Steve

adrianp · Post by **adrianp** » Thu Dec 13, 12 12:03 am

Hey Steve,

I used a wire from the battery that can handle 20AMP minimum. I calculated the draw if all four lights were on and it came to under 20AMP so I figured that was a safe number to start with. For this I used the standard 3mm cable here which is rated at 27.5amp.

http://www.vehicle-wiring-products.eu/V ... dcable.php

You could go with the thinwall cable here:

http://www.vehicle-wiring-products.eu/V ... inwall.php

As they have a 2mm one that's rated at 25AMP. I just prefer the standard cable as I didn't have to apply much effort to break the skin of the thinwall cables and that just didn't appeal to me having something that looked that fragile. This is just an opinion, I'm no electronics expert.

In terms of terminal connectors the pre-insulated ones are here:

http://www.vehicle-wiring-products.eu/V ... sterms.php

and the non-insulated ones are here:

http://www.vehicle-wiring-products.eu/V ... blades.php

Just make sure you get the right one for your diameter of cable that you're running. For the relays I ended up with these here:

http://www.ebay.co.uk/itm/Premium-Quali ... OU:GB:3160

You have two choices from there how you wire into the relays. You could just put terminals on the end of your wires and connect them directly to the relay blades but you can also get connector blocks for the relays that look like this:

http://www.vehicle-wiring-products.eu/V ... ockets.php

They are a little neater in that you wire in all your cables to the block and then attach that to the relay.

The conversion I'm doing at the moment is on a non-mopar classic which does have a foot dummer switch but that doesn't enter into the picture. There's two distinct cables in the engine bay, one for the high beam and one for the low beam. I just tapped these in the front of the engine bay and placed all the relays and the new run from the battery there.

I've just this weekend finished the LED indicator conversion on the '66 and started looking at the headlights so I'm hopeful it will be similar to the other headlight conversion as they are both four headlight cars. I did start to notice some differences in the wiring diagram on the '66 around the foot dimmer so I'm not sure at the moment if that's going to make anything more difficult or not. I'll hopefully get a bit more of a chance to play this weekend and report any progress

adrian.

Steve · Post by **Steve** » Thu Dec 13, 12 12:22 am

Adrian.... Thats fantastic mate! Thanks a lot!

Was worried about wire sizes etc etc but youve cleared all that up for me. Will sit on the laptop tomw and start ordering bits n pieces to get started. Was going to wait till the spring but got the bug now!!

Cheers Steve

Dave-R · Post by **Dave-R** » Thu Dec 13, 12 12:59 pm

Crikey is Dan Stern still going?

We used to be part of a email group in the years before web forums. Auto lighting was his thing and he used to be really into stant six power for some reason.

Steve · Post by **Steve** » Mon Dec 17, 12 8:19 pm

Got most of the stuff now to get started but would like to read Antons thread on the subject....anyone know where it is please, I cant find it on here...

Cheers Steve

Dave-R · Post by **Dave-R** » Mon Dec 17, 12 9:55 pm

It's really easy Steve. Take the plunge.

Steve · Post by **Steve** » Sun Dec 23, 12 9:39 pm

Had the house to myself this evening so decided to get stuck into making up my lighting harness with relays etc, so I can eventually get to a point where I can just do a straight swap with the original....

Made up a small metal case to house the relays and Ive wired in the relay earths, power leads and the high/ low beam wires. Nothing cut to length yet as I need to be at the car to measure it up etc. Ive made up 4 earth leads for the lamps but again, not cut to length yet as Im not sure exactly how long they need to be so no point attaching anything to the headlamp sockets yet...

beats wrapping the kids prezzies eh!