I have bought an 85 d150 pick up. The engine, however, is a 1974 318. I am having a headlight issue. I have done a continuity test on the bulbs, they're fine. Did a voltage test on the connectors to the headlights, and am getting 1.6 volts, so it's not good there. l Have tested fusible links am getting continuity there, too.
All the fuses are good, but not the right fuses, so am going to replace them. Got 30 amps where 10 amps should be. However, with as strong as the fuses are, I should be getting power there. I think the problem might be the connectors at the headlights, but my husband thinks it's the headlight switch. Anyone, got any suggestions?

 

Should post in the first gen section. Check for power at the headlight switch(going in and coming out if it). If you have power then check the bulkhead connector, If good then you should have power at the headlights. When you checked power at the headlights did you use the ground at the plug or did you use the battery negative? Possible bad ground if you used the one at the plug.

 

Moved to First Gen section.

 

I didn't know there would be anything like this, Where would the bulkhead connector be located? Checking the headlight switch and the wires to it was going to be my next move. Thanks for your timely reply.

 

Bulkhead connector is outboard of the brake booster on the firewall. Square block with lots of wiring passing through.

Headlight switch is a common failure item. Especially if stronger/brighter lamps have been swapped in.

 

You made sure your headlight bulbs were good, didn't you?

 

Thanks for the help. It was the headlight switch.

 

Ive replaced alot of headlite switches and /or dimmer switches for this issue. Do you have brights OR dims? or neither?