First how do I determine whether its a base / custom or limited? Secondly: Neither rear window or rear locks work. It blows the #18 fuse instantly. Where do I begin? Car has about 70k and is all stock. Thanks

The easy way to figure out if it is a Custom or Limited is to look under the "LeSabre" plate on the tail light.

Custom versus Limited doesn't matter for this fuse problem.

How many miles have you had this car?

Did these work fine until recently?

Was there major precipitation in your area just before this issue started?

Does the fuse blow instantly when installed or instantly the first time you use something like electric locks and windows?

Been in a garage and driven 2 times a year for last 10 years. Problem has existed all that time and I am ready to start driving it regularly now. Never in water. Drove it today about 10 miles after flushing coolant, UIM and Lower intake gaskets. Runs and looks NEW except for fuse issue. car has about 70,000 miles.

Sounds like a great car!

Does the fuse blow instantly when installed or instantly the first time you use something like electric locks and windows?

As soon as fuse is plugged in.

Do you have a DVOM? You have a dead short if the fuse blows when installed.

Yes I do have a vom. Was going to look into exactly what all is not working besides rear door locks and rear windows in a few days. Was hoping to find a wiring diagram with wire colors to see what wire is coming out of fuse 18 and where all that goes. I saw some where that fuse 18 is RRDR. Not sure is that is right rear door or what?

charm.li has a diagram.