Good Evening,

So I just bought a 1987 ford 350 dullie with a 460 engine. Anyhow the guy that had it really didn't take care of it and it has lighting issues that I need to address first.

so problem 1.

When lights are off both rear turn signals work. If head lights are on the right turn signal (rear) will not work however the right does... the other thing is both front turn signals do not work but I have not checked the bulbs yet. Both reverse lights do not work either and the hazord lights do not work either.

So where should I start with this.

 

You have a bad grounds on the rear end.

 

Meaning what... could this be inside the actual light housing unit or in the wiring or both I guess

 

Any time your brake lamps or turn signal work with the lights off and not with the lights on they are grounding back through the marker lamp wiring, brown wires. Then when you turn on the lights you lose this ground.
What ever grounds the bulb holder is not grounded. This could be a wire running to the the fender inside the head lamps on the drivers side either broken at the bulb holder or the circuit it runs through to get to the head lamps on the drivers side of the body of the truck.

You may also have a bad cab body ground.

 

so should I test the wires coming to each of the rear lights to see if I get 12volts? Thanks for all of your help thus far much appreciated.

 

You have the 12volts at the bulb but you have no ground at the radiator support on the drivers side for the tail lamps and it also sounds like no ground on the radiator support on the passenger side for the front lamps.

As I said above you might just have a bad cab body ground from the NEG post of the battery to the body.

 

So how do I go about fixing this

 

First check your NEG post of the battery. Does it have 10GA or larger wire going to a part of the cab (not the frame) someplace. Does it have a good connection at both ends?

If the Cab is grounded OK then check the two grounds on the radiator supports, one on each side of the truck. Make sure each has a good connection. These two grounds are G801 and G802.
The book says inter fender behind headlights for each of these two grounds but I think that is called the radiator support.

 

Ok sounds great.... I will look into this and post a response sometime soon and if needed I will take some pictures. Thanks again for your help thus far.

 

A bad ground could also effect the break lights correct? And if once I find it and fix it if break lights still do not work first thing is to replace the breaklight switch on the pedal correct?

Thanks in advance