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I have a 61. Recently, the headlights have gone very dim. Also, If I click the bright lights, all four glow very dim, some almost not at all, if I click the brights off, the middle two lights burn decently bright. I'm unsure if this is related, my headlight swtich was loose so I took the **** off and tightened it up. This made no change on the dim lights.
I'm assuming a ground. What are the common areas I should check?
Dig out your DVM and first measure battery voltage. Next pull a headlamp (or better still leave it connected) and measure voltage across the headlamp terminals. If that voltage is significantly less than the battery voltage then move up the food chain through any connectors, dimmer switch, and headlamp switch until you see near battery voltage and where it changes is your problem. This does assume that you have 12.6 VDC or so with the engine off. A fairly common problem is corroded breaker contacts in the headlamp switch itself especially on old beasts like these.
The first thing I would do, is make sure the headlight grounds are connected to a good ground upfront. Add a ground from the bumper to the headlight socket and see if that light brightens up. I suspect you don't have a good ground. It's possible to have low-voltage causing it, but I'm betting on the ground circuit.
The 61 wiring diagram shows all the front lights are grounded at the generator case.
Thank you for the replies. My first inclination is also a bad ground. One question, in looking at the wiring diagram, it looks like the headlight grounds to not tie into the generator, but rather to a junction that ties them all together, along with the horns, and that junction then has a wire that travels inside and connects to a series of grounds that covers the under-dash components. Do these junctions mount to the frame, or if not, does anyone know where they eventually ground to metal ? On the diagram it looks like they all just ground to each other.
They ground to the generator case which is bolted to the motor, which is grounded to the frame by a strap. If you notice the junction does not show a ground. The only ground shown is right beside where the black wire is bolted to the generator case. As I said earlier, you can run a temporary jumper from any known good ground either battery negative or front bumper, etc. to bypass the ground. connect it to the black wire coming off one of the headlight motors or at the black wire where it attaches to the generator. Before you spend any time troubleshooting wiring do that to verify that your ground is what the problem actually is.
all the diagram is showing you at the junction is that all the wires have the same ground.
The first thing I would do, is make sure the headlight grounds are connected to a good ground upfront. Add a ground from the bumper to the headlight socket and see if that light brightens up. I suspect you don't have a good ground. It's possible to have low-voltage causing it, but I'm betting on the ground circuit.
The 61 wiring diagram shows all the front lights are grounded at the generator case.
Weak Headlights
