Can someone help me to find out why All my lites are out.? My 48 f1 6cyl 6volt pos ground last week blew a headline fuse.I replaced it,worked fine all week,now no headlites,tailites,brakelites ,gauges work,no lites on dash ,horn works, truck starts and runs.Checked fuses all are good,any help would be appreciated

 

Headlight and/or the dimmer switch.

 

Which aftermarket harness do you have? There are no fuses in a stock harness, but there are two circuit breakers. One of those controls power to the light switch/headlights/tail lights. The other controls the brake lights.

Does your truck still have those circuit breakers under the dash?

 

Get a test light and check for power.

 

What's a headline fuse? As 76-5.0 indicated, start by checking your power connections.

 

You mentioned that you replaced a blown fuse and it fixed your lights for a week, Is that same fuse blown again? If so it may be a place to start. It could be as simple as water in the tail lite , shorting out the circuit or something that requires much more researching. Im not familiar with the pos ground system, but here is a schematic that may be of some help. Ther are several schematics this is the only one I have at the moment but if you need another one (out of the shop manual) Im sure someone will be glad to post it for you. Im just very pressed for time, IM cooking dinner , I hope this helps along with what has already been posted.

 

I found this other Schematic on the internet, best of luck.

 

Do you have power "in" to the headlight switch?

 

I think that we need a bit more information and pictures. Also what is your skill level? Do you know how to trace electrical shorts with an ohm meter?