What causes the 30 amp starter/HBL fuse to blow?

you may have a short (verify the integrity of the insulation of the positive wire from that fuse going to the rear window defroster, check the relay & switch.) try to replace the relay.

The starter and the fuse probably have nothing to do with each other... although it's POSSIBLE that your car (whatever it is) might have a starter relay that drives the starter solenoid, in which case I'd suspect the starter relay.

You'll need to track down everything powered by that fuse, find the offender (the one using too much current), and correct the problem.

Hi S, It seems to me that the surge may have been caused by the alternator before blowing. A short circuit may has caused the diodes to blow, which in turn will probably have been caused by a short circuit created when the radio theft took place. The first thing to do is isolate all loose cables and make sure that there are no internal shorts inside any auxiliary equipment. After making repairs to the alternator, or fitting a replacement, disconnect all connectors to switches and other controlled units such as cabin heating and ventilation systems, music, TV and navigation systems. The fuse box is located in the engine compartment. Check all for continuity and replace burned fuses and at the same time, check for any damaged relays. Once are you satisfied everything is as it should be turn the ignition key to auxiliary and check all cables for overheating. Connect each unit one at a time until a fuse blows or all are connected. If a fuse blows while connecting, replace the fuse, but leave that circuit disconnected and continue until all are connected or another fuse blows. Once the dangerous circuits have been identified, trace the fault either into the wiring harness or the units. Repair if possible or replace. Once that has been done, crank and start the engine. Check all circuits with the engine running and the park brake fully engaged. If the engine fails to start check the electrics which operate the starter motor. Hope this info is at least a little helpful. Regards John

sounds like a bad ground somewhere or check your ground wire on your starter and even your igniton switch cause if they go bad then your car either wont start or wont stay running

Pls be more specific, doe's this fuse keep blowing or what? Fuse blows and your car won't start. I have a 2004 GTC and the #8 fuse kept blowing, had to replace the starter, (it was pulling 80amps instead or the normal 30-35) once the starter was replaced, no more starting issues and the fuse no longer blows. Hope this helps, good luck

starter fuse should be 30 amp not 20 amp this is the problem replace with 39 amp

This 30 amp fuse, If it blows when cranking, it is usually the starter dragging, if it blows by just turning the key on it is usually the fuel pump drawing too many amps.
I hope this helps.

is it the crank fuse if it is could be starter drawing to many amps try new starter

you need a new starter I just went through this problem had my starter changed and have not blown any fuses in days....oh and by the way getting to the starter was not and easy task.

that fuse feeds power to fuel pump relay circuit that feeds pump could be defective pump,or damaged circuit wires that shorts out! and not a good idea to put higher fuse in circuit could cause more damage to circuit! but i know when your stuck, u do what it takes,so inspect circuit related to fuse,