Thanks for the replies

The car is a 2-door made in spring of 66'

I've noticed the dash lights are fed off the same circuit that feeds the taillights, so it's possible the problem could be with the dash lighting as well.

A fuse is blowing when the lights are turned on, pulling the wire off the fuse block that supplies the taillights stops the fuse from blowing.

There is no problem with the parking lights.

I'll have to see if there is a clean way to remove the dash lights from the circuit.

Bill

If you have a late car the loom may be the same as the GT one. This has a black wire for the trunk light and this commons up with a similar black wire for the under hood light. These get their power from the bottom, 5amp, fuse. This wire from the fuse box doesn't feed/supply anything else.
Ref: Haynes 123GT wiring diagram p.194

Bill;

To go along with the info which Shannon has posted*....:

...there are variation by year, so you need to be more precise in your vehicle info...why don't you just disco the six circuit conns at the tailight assemblies one at a time...if the short goes away, you can be pretty certain that short is downstream in the tailight assemblies, and those are pretty easy to remove and troubleshoot/refurb...(use a temporary sacrificial fuse to save your shorty 25A...or better yet troubleshoot without full power and blowing fuses with an ohmmeter or continuity beeper).

I have seen a spare (unused) brown wire in the trunk (comes out of sleeving, but doesn't connect to six circuit connector), but it doesn't show up in the wiring diagrams and I seem to recall it terminates in the area (comes out of sleeving) of the six circuit conn under dash...

Good Hunting!

*although I doubt DIN spec has much to do with it...that didn't come along until later...

It appears I have a short in my taillight circuit somewhere...

Howdy Bill,

I want to make sure we are using the same terminology. A short produces a blown fuse. An open prevents operation of a circuit without a blown fuse. Are you blowing a fuse?

Do you have a wiring diagram? If you need one, go to volvoamazonpictures.se and follow the document links to get the Green Book for the Electrical System.

What year is the car? Wagon, sedan, or GT? There are slight differences between them. Nothing major and nothing you can't figure out with a generalized diagram.

The driver's side rear 6 pin block carries four wires to the front 6 pin block. The colors on the drawing I am looking at are red, white, green and blue. A fifth wire, grey (backup lights) leaves the rear 6 pin block and goes through a single connector midway to the reversing relay. The only other wire on most models is the fuel gauge, black wire. Some of the newer models have another black wire intended for the mercury switch used on the trunk light. Those are all the wires running into the trunk.

Be aware that a wire that made the entire trip to the trunk as a blue wire changes color to green in the passenger side 6 pin connector. There are only four positions used on the passenger side connector and that is the only color change from one side of a connector to another that I've found anywhere in the car. That had me a bit bewildered when I found that on my car; I thought someone had incorrectly wired the connector until I checked the wiring diagram. I reckon that change is made to conform to a DIN standard?
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Mr. Shannon DeWolfe -- I've taken to using mister because my name misleads folks on the WWW. I am a 52 year old fat man. ;-)