Hey, I have a 75 B300 van, has a 318 and 727. The other day while the van was running, with the lights on, the taillights and running lights went out. My rear blinkers work but no running lights or brake lights. Just replaced the switch and all fuses in fusepanel. Does anyone have any info on why this might be happening? I have heard about fuseable links but dont know where they are. Any info would be awesome, thanks.

 

Locate and clean every ground you can see in regards to your lights, your problem sounds a bit odd so my money is on one or more bad grounds.

 

It's not a fusible link issue. It's more likely there's an issue with the wiring running back there.
What switch was it you replaced?

 

Hi, thanks for the reply, I just replaced the headlight switch.

 

Thanks for the reply, I will go through all the grounds, any info on where to find a diagram of ground locations?

 

Follow the wires from the tail lights, you'll see them.

 

they all come together at teh turn signal switch, that's where I'd start looking.

 

have you looked at the sockets at each light location for corrosion? Corroded sockets/connections to bulbs cause serious problems with lights. Go at corrosion with fine sandpaper, a wire brush and a spray can of contact cleaner

 

^^^ That. Clean up the sockets and the connections. Replace the bulbs if they are corroded and coat the socket with white lithium grease to keep them dry in the future.

If that fails check the wiring using a voltmeter, or a tool similar to this:

http://www.jegs.com/p/JEGS-Performan...58032/10002/-1