Thanks in advance for any and all help. So I got a 94 ram a while back and up until a couple of days ago I thought everything worked fine. Turns out my third brake light doesn't come on when the head lights switch is all the way out (pull switch), when the vehicle is placed into reverse, or when the brake is applied. However the reverse/ cargo light comes on when the pull switch is rotated to the cargo position. When I bought the truck it did have a shell on the back of it but the third light for the shell is made up at the rear tail lights. None of my fuses are blown or missing from what I can gather and everything else is in working order. Any insight into what the possible causes would be is greatly appreciated.

 

Does the third eye work correctly when the headlights are off?

 

Only when I turn the switch to cargo and then only the whites light up. Thanks for the help with the hazards that fixed them.

 

Cool. Happy to help.

The red light in the center should only come on when you step on the brakes. Did the cap have the third brake lite on it as well? Might just be a minor wiring issue.

 

I would remove light unit, take out the bulbs in question (I assume you checked and verified that they are good) and have someone push brake pedal while you check for voltage at socket. Wiggle wires around (Dodge put a rats nest in there to split off to four bulbs).

And in case you were ot aware, there is a free download servivce and parts manual in the FAQ/DIY section. That alone makes the membership fee worthwhile here!

 

The cap did have a third light on it but I never connected it and all of those wires are made at the left tail light as far as I could see but I am going to try and take off the electrical tape and see where they actually go. I did a little bit of part swapping with the bulbs and they all worked but then again I didn't do an actual voltage test. I got some spare time tomorrow (kind of want daylight so I don't go breaking everything) so I'll give that a whirl and let y'all know what comes of it.

 

The service manual has a wiring diagram that may help also. I often print the pages I need to take out to truck to work.

 

Before you put the light assembly back in after it's working, use a thin bead of silicone on the gasket. That lite is a common place for leaking water.

 

There is no voltage between the tan and black wires on the third brake light and nothing at the light. However I went straight to the brake relay and tested the same wires there and got around 13v with the truck running and that is from the black to both tan wires. So I know its not that. Would the cap light wiring at the tail light block the third light from getting power?

 

Do your brake lites work? The White wire with tan trace coming out of the brake switch powers all the brake lites. it breaks off to the turn/hazard switch for the rear lights, and continues on to the third eye. See if you are getting power at the third eye.