• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Wires from license plate

jboomer

Sr. Member
Joined
Oct 17, 2007
Messages
506
Loc.
Havelock, NC
I'm trying to get my truck ready for its annual inspection. For some reason, when I turn on the headlights and either blinker, the right tail light goes out. It'll still blink, although VERY slowly. When the headlights are off, it blinks the way it's supposed to. I have two wires coming off the license plate, only one is plugged into anything though. Both are "HOT" when I turn on the head lights. Anyone know where the second one plugs in? Could this be why the tail light goes out with when the blinkers are turned on?
 

cgbexec

Bronco Guru
Joined
Sep 19, 2006
Messages
2,071
Loc.
Naples, FL
One of the wires comming off of the license plate light is a ground and is not supposed to be hot. One wire should enter the harness and the other is ground.
 
OP
OP
jboomer

jboomer

Sr. Member
Joined
Oct 17, 2007
Messages
506
Loc.
Havelock, NC
One of the wires comming off of the license plate light is a ground and is not supposed to be hot. One wire should enter the harness and the other is ground.

Then that thing is shorting itself out. I'll go take a look! Thanks!
 
OP
OP
jboomer

jboomer

Sr. Member
Joined
Oct 17, 2007
Messages
506
Loc.
Havelock, NC
I removed the bulb from the license plate assembly and it looks like that was potentially the culprit. It appeared to be the original bulb and was occupied by 30 years worth of dirt and a dirt dobbers nest. I'll replace that tonight.

In the meantime, any one have any idea where the ground is for the tail light assembly? There's a ground in each of the tail light housings, but I think those are for the side marker lights. I'd like to check and ensure I'm getting a good ground for the lights and hopefully fix this bad blinker.
 

oleguy74

Bronco Guru
Joined
Mar 26, 2008
Messages
2,034
Loc.
calif city ca
the lite buckets ground them selves.one wire in license plate lite is hot other goes to ground.if bulb is good you will read both hot if the ground is not connected.
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,316
I removed the bulb from the license plate assembly and it looks like that was potentially the culprit. It appeared to be the original bulb and was occupied by 30 years worth of dirt and a dirt dobbers nest. I'll replace that tonight.

In the meantime, any one have any idea where the ground is for the tail light assembly? There's a ground in each of the tail light housings, but I think those are for the side marker lights. I'd like to check and ensure I'm getting a good ground for the lights and hopefully fix this bad blinker.

You could always run all the light grounds to a common point on the rear frame rail. Mine is like that but I think I did that many years ago.
 

Brinco

Jr. Member
Joined
Sep 21, 2007
Messages
74
I was having a similar problem with my electrical and after spending numerous hours I traced it down to the license plate bulb socket. Sometimes the ends of wires that feed up to the socket get mashed down and the hot feeds back to the ground causing issues. You might need to replace the socket.
 
Top