Hi Evan (and anybody else who might know), I seem to remember Evan posting YEARS ago how to wire in a headlight relay so the headlight switch itself is not taking all that juice (amperage when the lights are turned on. Seemed like a pretty good idea for increased safety of the vehicle back then. Anybody (Evan) remember that post or how to do it? Thanks, Andy
Andy, Bill Hanlon is the resident guru on electrical subjects. Probably the easiest would be to put a relay (30 or ? amps) between the head light switch and the dimmer switch. It takes a small draw from your factory head light to dimmer wire to activate the relay which can then pass a high current through the relay to the dimmer switch. On AD's with a stomp starter there is often just an ignition and accessory terminal on the back of the factory ignition switch so for ones wanting to keep the factory switch we run the accessory wire through a relay to a bus terminal block so all the modern toys can be hooked to the block. The relay amp size is the total draw of all the toys---electric fan, fuel pump, power windows/seat/antenna, sound system, etc. Now days a replacement harness takes care of all this. I'm sorry I can't do drawings on a computer but would be glad to send one done with pen and paper through snail mail.
I'll get something drawn up for you later today, Andy. Is your truck still running a 6 volt electrical system or has it been upgraded to 12v? Do you plan on keeping the headlights currently in the truck or would you like to allow for upgraded headlights? There are 12v relay-based headlight harness available or you can do like I did and make your own. The "generic plug and play" harnesses wouldn't work on my '52 without cutting them up because they depend on space behind the headlights to mount the relays and an additional male and female plug like the one on the back of the headlamp. Nowhere near enough room to do that in my truck. So I made my own. Not as pretty, but works great. Instead of just doing splices I replaced the 4 position terminal board on the driver's side inner fender with a 10x2 position terminal board.
I used waterproof relays & sockets (the pin numbers are the same as standard Bosch relays), but you wouldn't have to. My headlights are Hella 7" (looks stock, but the face is a little flatter, DOT approved) that take standard 9003 (H4) type bulbs. I'm just running "stock" (DOT approved) 60/55 watt bulbs, but you can get them up to at least 100w.
Bill, thanks for the pictures and text! This will see use once I put the hammer down, and pick up a wrench again. A side note, there are HID kits for 9003 style sockets. A quantum leap in lighting. The Hella's focus light so well, there is zero blinding of oncoming traffic.
The reason I upgraded to the 9003 lamps is that we moved to the country 3 years ago. The whitetail deer think they have the right-of-way and they are really stupid. At least I have a better chance of seeing them now. I don't like putting up with other driver's HID lights, so I think I'll just stick with the 9003s. Instead of the description of my wiring, I'd be glad to just supply a wiring diagram. But I'd like to hear from Andy first about his truck (6 or 12 volt? headlight upgrade in mind?)
Hi Bill, Thanks for the info. My truck is 12 volts and I'm not planning on a headlight upgrade. I just want to get all that power from running through the switch, Thx again, Andy
Andy: You'll need to decide how much of the present wiring needs to be replaced. If in good shape, you can keep it all and just mount the relays near the left inner fender panel where the junction block is. That way you'd only need to run one wire from someplace that had 12v all the time (where the battery cable attaches to the stomp starter switch is a good place) to the relays. Next question: Do you have a voltmeter that will measure 12 volts DC?
Bill, If you mean do I have a voltmeter installed in the truck the answer is no. I do have a multimeter that will read voltage though. It's an analog one, not a fancy newer digital one though. Also and BTW...does anybody on here have experience with the quality of a reproduction headlight switch? Andy
Multimeter is what you'll need. Set it to read 12V DC. Connect the black test lead on the multimeter to ground. You are going to identify the terminals on the 3 position junction block that is mounted near the top front of the driver's side inner front fender skirt. For ID purposes let's refer to the terminals as "front" (nearest the radiator), "rear" (furthest from the radiator) and "center". Turn on the parking lights. Touch the red test lead on the multimeter to each terminal until you find one with 12 volts. Note which terminal (front, center or rear) has 12 volts. Turn on the low beams. Touch the red test lead on the multimeter to each terminal until you find one with 12 volts. Note which terminal (front, center or rear) has 12 volts. Turn on the high beams. Touch the red test lead on the multimeter to each terminal until you find one with 12 volts. Note which terminal (front, center or rear) has 12 volts. Now do the same to the 3 position junction block that is mounted near the top front of the passenger's side inner front fender skirt. Turn off the lights and the multimeter. You should end up with a chart that looks something like this: .................Driver's side....................Passenger's side Front........Low beam..........................Parking Center......High beam.........................Low beam Rear.........Parking..............................High beam but which terminal is low beam, high and parking may be swapped in your case.
All very good . Just getting the headlight's power draw out of the dashboard switch is really smart and helpful . To use the simple and cheap cube typ relays, try this : how to wire headlights using relays - Google Search
The first relay drawing that comes up when you follow the link in Nate's post # 11 bypasses the dimmer switch. It will turn on the low beams (or maybe high beams depending on how you connect the two wires from) when the headlight switch is turned on. It has no connections for the high beams (or maybe low beams). Plus, these relays don't have two # 87 terminals. They have one #87 (normally open) terminal and one #87a (normally closed) terminal. Just because you found it on the internet doesn't make it true (including some of my stuff).
Thanks for the info Bill and yes, I would liek awiring diagram as well if you have the time. Happy Independence day. Andy
I prefer to put the relays (I use two cube relays, one for high and one for low beams) as close to the headlights as possible, this keeps the original under dash wiring intact and simply shortens the current path between the battery and headlight bulbs proper .
That is what I'm planning on giving Andy. My assumption is that the existing wiring is complete and in good enough shape to use. If so, all I really need is his readings for post #10 above for the driver's side only. Give me those results and I'll get you the diagram Andy.
Looks pretty good Bill ; I'd be very cautious about using a higher than 10 or maybe 15 ampere circuit breaker unless there are 10 watt head lights being used . As e said he just wants the stock ones to be as bright as possible I'd think a 10A would suffice .
10 Amps would be right at the limit for two 60 watt headlamps at 12 volts. Maybe over limit at high generator/alternator output.
