My 76 xj12 keeps blowing fuse #3. This is a 35amp fuse that powers most of the interior accessories. What could be wrong? Where to start?

Does a new fuse blow *instantly* ?

Is there one particular accessory that always blows the fuse? Or combination of accessories?

Do you have a wiring diagram?

One method is to determine exactly what's on that fuse and systematically start disconnecting sub-circuits until the fuse no long blows

Cheers
DD

Yes, the fuse blows instantly and yes I have a wiring diagram but to me it's useless as I am an electrical moron. Your suggestion on sub circuits make a lot of sense, that is where I will start.

Do you have a cigar lighter. Has something , like dime, dropped into it. I have known this to happen.

Roger

Nothing in the cigar socket, but it is crusty in there.

That's an easy place to start. Unplug the lighter wires.

Cheers
DD

Does the fuse blow before you turn the ignition on.

Roger

The fuse does blow before the ignition is switched on.

In that case it has to be an item that is permanently powered.
Possibles are: Ignition Switch, Interior Lights, Clock, Door Locking, Hazard Switch, Light Switch, Footbrake light switch., Radio.
I do not have a diagram for your vehicle but if you can see the fuse on the diagram then follow the lines to the items that it powers.

Roger

I have a Haynes manual, is this a good choice or is there a better repair manual?

The Haynes should be Ok. I have the 86 XJ6 one so I admit it is pretty cluttered as everything is on one page. But you will need to persevere with it.

Roger