Help with Headlights

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Aug 3, 2003
I've got an issue that I've been trying to correct. My headlights on my 40 are dim. They do not get brighter with acceleration. I know that a bad ground can cause this but I've been unsuccessful in finding a bad ground. Any help or experience would be appreciated.
I'd check the contacts on the plugs, your headlight ground is supplied through the 3-prong plugs. I would also probably just replace them with OEM's from Napa. I had one burned out, replaced it with a stocker from Napa, and it is significantly brighter than the other one.
No matter what you do, they will never be very bright.
Then get some good aftermarket fog lights.
and dusty or dirty switch terminals in the steering column or any of the other wire joints along the system. The standard wiring does not use relays and runs all current through the 2 switches. It could be anywhere.
For around US$115 you could have some bodacious bright headlights, if you wanna' spend the money. IPF glass, H4 bulbs, relay equipped wiring harness. After driving the cruiser at night, getting into my modern soccer-mom minivan, I feel like I don't even have my lights on.

"SEARCH" will find lots of explanations of how this is done.... or email me.

You could just add a relay and clean up the wiring contacts.

John Sherwood '79 FJ40
Charlotte, NC TLCA, Upstate Cruisers
A common multimeter (10$, made in China) comes in handy for determining electrical problems. Measure the voltage across the lamp. If it's lower than 12V then it's a wiring/grounding or switch corrosion problem. If it's 12V or more, replace the light bulbs.

Thanks everyone for your posts. I have replaced the headlights and the problem still exists. High beams are what low is supposed to look like. I will do some tracing of wires and see if I can find out the problem.
first thing might be to check the high beam switch make sure the wire hasnt come loose and that its getting power.
Chances are it is a bad or corroded connection in the supply circuit. To find it measure the voltage drop across the circuit with the lights on. Put the negative lead of you volt meter on the + post of the battery and the red lead on the light bulb terminal. A reading more than 0.5 volt is too much drop. Keep measuring the voltage back through the circuit at the switch and fuse block to find the bad connection.
I know the H4 systems are a nice upgrade, but if you just replace the wiring harness and use cheap haolgen sealed beams you'll likely see a big improvement.

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