The Stovebolt Site Forums The Shop Area The Electrical Bay 6 volt truck head lights?

I have a 6 volt truck 3600 and plan to keep it that way.

Which head light will work best? Halogen or led? I have changed the break lights to led and they work great. Highly recommend everyone do it for safety reasons.

Thanks Don

Don, I can't help on the LED/Halogen question (though I'm in for responses) but have you added relays for the headlights? When I did my stock 6v headlights improved by about 100%.

Relays installed in the headlight wiring is absolutely amazing. Well worth the little bit of effort.

Relays, interesting. Does it also have an effect on the tail lights? Sources?

Rick

How does the relay system work? Where does the relay go?

Thx Don

The relay is wired direct from the battery waiting for the headlight switch to activate it.

Don, what year 3600 do you have?

Is there a GM part # for this headlight relay?

Many here on the “Bolt” have added headlight relays to their 6 volt systems. Just go by your local FLAPS and tell them you need a headlight relay. If they want to know what it fits tell them it doesn’t matter. You can explain what you’re doing but more than likely if the counter guy is under 65 he’s/she won’t even have a clue. Google 6 volt headlight relay and pick one. Come on guys someone make it easy for Don and Fonz and give them part #s and a wiring diagram.🛠

Ask for a relay to operate an aftermarket electric fan. It will work and have a relay with a tab which has a hole in it for screwing it securely in place. It may also come with a handy wiring harness.

I have a 49 3600. Wish it was a 3100.

Don

I put a reflector type assembly on my 51 that uses the H4 style bulbs. It is difficult to tell from their appearance that they are not the original style sealed beams. They provide excellent lighting, at least if not better than a vehicle of the 80s. You can get the bulbs in 6 volt or 12 volt and you can get 6 volt 65 watt bulbs. You would definitely need the relays with the 65 watt bulbs. I bought mine from Octane lighting and they fit right in. Chevs of the 40s sells a similar product but they in their description they say that some modification will be needed.

My research indicates that the original headlight relay was a Delco Remy part # 1116789. There are several on eBay at this moment--some include the original wiring diagram.

LUKE

Does it require one or two of those relays to do the job??

Here are the relays I used. I also used these relay sockets or harnesses.

If you do make the upgrade to relays I'd suggest buying an extra for the glovebox. Most retail outlets (as in very likely none) will not have a replacement should one fail.

Good Luck, Ron

Two, one for low and one for high beams.

Thanks!

A relay is just an electrically activated switch. For the headlight solution mentioned above the power going to your headlights will run thorough a large gauge wire (10-14 GA) that will run from your battery (or alternator) to the relay and to the headlights. Because this wire is bigger and shorter (shorter because it doesn't run from the battery to the headlight switch to the headlights, just to the headlights) there is less voltage drop. A little voltage drop has a huge effect on your 6 volt bulb brightness and the bigger/ shorter wire greatly reduces that voltage drop and makes your lights brighter. The headlight switch uses a 16 or 18 GA wire (smaller stock wire size) and switches the relay on and off which starts and stops the power to the headlights. The relays you want are sold at about any auto parts store or online for a couple of $ each. Here is a diagram showing how to wire it.Wiring diagram for headlight relays I've also attached the image. In the image the numbers 30, 85, 86 etc. are the pin numbers on the relays.

A second advantage is you are not running a lot of current through your headlight switch and associated wiring. The headlight switch only uses a little current to switch the relay and the big current load to the headlights goes along the big wires from the battery to relay to headlights.

Here's relays for $2.95 that I bought along with some LED gauge lights. Relays for $3

Google the topic and there are a zillion diagrams, YouTube videos etc. on the subject.

David

David, GREAT explanation....However 6 volt relays were a challenge to find when I searched early this year. My Napa guy who is usually up to any challenge was stumped. Same with Oreillys.

Hi Moparguy,

I found this package of five, 6 volt relays on Amazon for $24.
I think they might work for what we are trying to do. 6 volt relays from Amazon

David

Is a horn relay the same a light relay?
Harold

Harold, the same relays can be used for both. The relays take just a little current from the headlight switch (or horn button in this case) and can handle upwards of 30 amps (exact rating will be on the packaging) to whatever your controlling {lights or horn). In fact when I work on modern vehicles and am trouble shooting, I've found that the relays on my cars are all the same I. E. I can swap one for the others to check for a bad relay. Most cars have four or so relays mounted under the hood near the fuses etc.

David

David, thanks for taking the time to give a thorough explanation. I’m a real dummy when it comes to the electrical side of these old trucks. Taught myself how to wrench on them but always shied away from the electrical problems. I’ll look for some videos on YouTube and will Google the topic too.