The Stovebolt Site Forums The Shop Area The Electrical Bay Taillight now not working

Just got the 66 back from paint and checked the brake lights. Had one out of two working. Thought it would be an easy fix. When I took off the lens, the bulb was just sitting in the housing so I thought the bodyman forgot to put it in the socket. I tried to get it in and it wouldn't seat like it's supposed to. I went over to the other
(working) taillight to compare and it was pretty coroded in the housing but it WAS working, now neither are working so Im thinking the truck is not grounding well enough even though it was working before I messed with it.
Anybody have any answers as to what I need to do to get them working again.
If I need to get a better ground, what method would be best. Thanks all.

steves66c20,

It sounds like you have things well in hand. Make sure both lamps are good and the contacts on them, and the sockets are clean. Use your vise-grips to attach a wire to a good clean frame point, and touch the brass housing of the lamp holder.

If this does it..you will have to clean a good path to ground through your freshly painted taillights, making sure the bed is well grounded to the frame.

If this light assembly is common with the taillights, they shouldn't work either if it is a ground/fresh paint deal!

Stuart

check your grounds, or run a separate ground wire.

sometimes I have to tap on one of mine and bingo

New sockets are available. We used to put a drop of tin solder on each bulb contact, would get more years out of old sockets.

Ran a ground wire from the frame to the bed, (cleaned both areas down to shiny metal) and then I got some current with my testor. Tried a bulb and at first it didn't work then I tried it again and it lit up. So I thought I had it resolved. Then I took the housing off cleaned it up and cleaned the brass socket connector and now, I have zilch power for taillights, brakelights and turn signals don't work!! I must have a short cause I got good current, then nothing. Ive orderd both a front amd rear taillight harness but Im still bothered by this situation. Any thoughts as to why Ive totally lost any juice.
By the way, the front lights are fine.

steves66c20,

Don't give up. The taillights and brake lights come from different sources, so whatever the problem is must be in the lamp assemblies or a ground issue.

The 'ice pick' style voltage tester allows you to ground the pigtail and probe tight little places, like the contacts inside a light socket.

On your rig all these circuits are fused, so a dead short would result in a blown fuse. If all the light functions are dead on BOTH sides, the commonality to this scenario would be a lack of a good ground. Keep poking around and keep us posted.

Is there a plug setup on the firewall that involves these wires headed back toward the rear of the truck?

Stuart

Yes, that is my next place to check, it may have gotten disconnected or partially making contact. it doesn't seem likely, but desperation has set in!
I plan on cleaning up the housings and running grounds to each individual tail light assy. as soon as I find out why Im not getting any juice.

This should be a simple fix, but of course that wouldn't be any fun...........

Many times the bulb works, but the contacts on the "old" bulb are worn down from vibration. The bulb works intermittently becasue it looses contact. If the contacts are worn down in a concave shape, replace them.

steves66c20,

I have enclosed a wiring diagram of the back half of your rig. It does show a connector for the brake/tail circuit. I wonder if the thing was pulled apart during painting and got dirty or only partially reconnected.

http://rmcavoy.freeshell.org/diagrams/66tailwire.jpg

You can enlarge this print with your cursor.

Stuart

Stuart, thanks for the diagram, it will certainly help assist me in getting this fixed. Ill let you
know when I figure it out and get it resolved.

cursor,curses,whatever.....lurkin my Arse
Steve,the diagram that Stuart gave you is right on.
The Actual connector if you have not found it yet is on the firewall, just below and to the pass side of the main harness. about the size of a silver dollar.
Unplug this and test out the different spades showing,there will be 4, Lt sig, Rt sig, Running lites, Stoplites.The Round connection plug head on will look something like this.
_ _
! !
The exclamations should be solid vertical lines direct under the center of the flat line, but you get the idea,DONT You

If all test out fine,
Then reconnectthe plug and test the wires at the juntion block at the rear crossmember and left framerail,should still be there unless eliminated by a prior butcher, Ahem owner for a prior short.
If All 4 test clean,Same test process of elimination,Now you know that you have juice to the back and can see if it is a bad ground or a bad socket/worn bulb.
Hint{an alligator clip jumper wire from the socket to a GOOD ground does wonders!
WATCH Out Stu might oughta wanna paint your house for that Diagram
Cheers,Good Luck,and Regards

Well, I ran a ground wire direct to the left taillight housing and now I have all my lights again. I did have to reclean the socket terminal buttons again as I still couldn't get the bulb to light up. after sanding it shiny or rough, I reinserted the bulb and got it to work consistently.
I don't have a junction block at the rear of the bed as the wiring was messed with by the PO
so I think Ill need to get one. Anyone know where to obtain one from? Thanks again for all your advice. This is a great website.
Steve.

Steve
Thanks for letting us know how you made out.
Glad to see ya got it fixed
regards