Hey guys, So I've run into a doozy here. Headlights working one day, next they're not. The other day I had no dash lights I realised so I ran the dash lights to the tail lights and that solved that but otherwise I've done nothing to the headlights. I pulled the three wires off the foot switch for high beams and tapped each of em to the floor with the lights on - zero spark from any of em which I rekon means there's no power getting to the dimmer switch? So no front parkers or high/low beams. But, I get blinkers for both sides. Checked both fuses on the switch - the lil one when pulled just meant no blinkers, big one was obvious so I didn't pull it. My friend has the same in their 60 tbird and swapped the switch - no avail. Is there an inline fuse or a headlight relay or something? 59 Fairlane for what it's worth.
Well first, you absolutely never "check to see if it sparks" with an electical wire that should be fused because you blow the freaking fuse in the process. Test light or volt meter not using a spark to check the system. Second only the power wire from the headlight switch to the dimmer switch will have power when all three are disconnected and then only when the headlight switch is turned on and working. You have to have a test light and or a volt meter rather than trying to do it (put in derigitory term) style. There should be a fuse on the back end of the headlight switch according to these diagrams. I posted both the 6 and V8 diagrams for 59.
Mr48Chev... good stuff. Is that "CB" I see a circuit breaker? I recall inline fuse holders under my dash before I ripped out the wiring. I don't recall any circuit breakers on my car, maybe the brown lamp cords replaced them. At least the OP has something to go by. I replaced my dimmer and HL switches when I did the harness swap. Also a new ignition switch.
The fuse on the end of the switch is for the dash lights and dome light only. There is no fuse for the head lights. There is an internal breaker in the head light switch that will trip if over loaded. The front and rear park lights are on when the switch is in the park position. When in the "head lights on" position the front parks go out, the rears remain on. The brake and turn lights are a completely different circuit.
If the contacts of the bimetal overload breaker are dirty, you'll get no lights. Sounds like the switch either has an internal fault or the breaker contacts are corroded. The breaker can be cleaned quite easily- fine sandpaper drawn between the contacts (but don't bend the arm!). If that doesn't fix it, you may be looking at a new switch. Phil
Cheers mate, thats the reply i was hoping for! However, my friend has the same issue in their tbird and new switch didnt help - guess we'll see!
I would strongly recommend getting a light up test screwdriver. Make sure you have power at the switch, where it comes in.
A month ago some advertiser on FB was pushing a Test light with a built in LED voltage readout. I snooped a bit and found one on Amazon for less than the FB one, bought it and a few days later it showed up. Here I was using the battery for my 18V cordless tools to check it out. I haven't used it enough yet to know a lot about it but for me it serves two purposes and those are being able to see if I have power to a spot on a vehicle and then seeing how much power I have. The main thing is figuring out where you have power to in the headlight circuit and why don't you have it going further than that. That means, is there power to the switch? is there power at the headlight pin on the switch when you turn the switch on? if so, is there power to the end of the wire at the dimmer switch? Yes, are you getting power though high and low beams on the dimmer switch when you switch it yes/no? ) NO go back up the wire and find out why you don't have power though it. ONE THING!! any time you use a test light or volt meter, make sure that it is working and properly grounded before you start testing. Under the dash that means checking the light or meter on a working hot connection like on the fuse block to make sure your tester is all connected correctly.
Check this voltage tester: https://www.jalopyjournal.com/forum...ter-3volt-dc-36volt-dc.1282368/#post-14727358
Dash lights and rear running lights are usually shared in the system. I'm in the line that says headlight switch, but you may have exigent cir***stances that made the switch act up.
I use a good old incandescent light tester. You can see if the voltage is low by how bright the light is and you can slightly load the circuit with the bulb to aid in finding weak connections. But yes, a test light is your friend on old cars (power and grounds).
Clean the connectors at the headlight and parking light junction on the left inner fender panel. You can also test front there to see if power is going them when the switch is on.
Changed the switch from my working 59 ford and scrubbed the firewall connector ‐ still nothing! Will get a test light this week and go from there.. doing my head in
Your supply to the switch is the terminal with 3 wires on it- 2 yellows and a blue/black. Do you have power on this terminal? It comes straight from the battery.
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