92 Astro blowing fuses

I have a 92 Astro that is blowing a 30 amp fuse labeled Horn/DM immediately after insertion. It does not matter if the van is running or if the key is in the ignition.

When the fuse goes it also takes out all of the overhead interior lights, cigarette lighter and radio. The Radio and interior light fuses are OK.

My Haynes book is no help, it does not list a 30 amp fuse in the block nor does it tell me what DM is.

Where are the most common places I should look for shorts.

Horn/DM (DOME) Fuse, this circuit has your domes, side power mirrors, compartment light ,horn ,vanity mirror lighter, panel dimmer, all stepwell lamps, High probablity are your vanity and lighter circuits. Unhook connector behind lighter and check your vanity circuit. Also mirrors can be disconnected, to isolate the fault. Good Luck!

Your radio has two power inputs one is fused with the radio fuse 15A which has power when the ignition is on the other is the 30A Horn/DM fuse which keeps constant battery power to the radio for station presets and the clock. Between the radio and the 30A there is also a 10A inline fuse, which should be behind the radio.

Having the same problem. Did you get it isolated???

Forgot to mention the power windows don't work either. The circuit breaker is hot. Is the problem related???

Just a thought, do you smoke? Is there anything in the lighter assembly? I have found pennies stuck in lighter assemblies causing problems. Is the lighter stuck in the pushed-in position? Also, ash in the lighter assembly over time causes the thing to short out, making it neccesary to replace. As for the circuit breaker being hot, that should mean there is a problem, The circuit breaker is designed to "break the circuit" and reset itself when the problem as been repaired. It's heat activated, meaning when too much current flows through it and heats up the metal contact inside of it, the metal contact will flex, breaking the connection. Once this metal cools the metal will return to its unflexed state, and closing the circuit again. In some cases a circuit breaker will not break the circuit and will just get hot. Hope this helps -Chris

I started checking the lighter and it looked ok. I disconnected it. It is my buddies van and I am just trying to help trouble shoot the problem. Disconnect component by component until the short stops I guess. Probably need to get a wiring diagram to see what's what. Thanks for the reply and I will keep the post informed on what is found.