I have a 94 Cadillac Deville that keeps blowing a fuse. The fuse is under the hood and is referred to as the IGN 3 fuse in the manual. It controls the 1.rear defogger relay, 2. electronic level control, 3. heated windshield, 4. heater and a/c programmer, and 5. cruise control. It started a few months ago and i have been forced to buy fuses in bulk quantities. I am having a hard time isolating the problem. My guess is something is shorting out along the wires. Has anyone had this problem or have any ideas of what it could be? Or any suggestions in what I can do to isolate the problem?

 

also, i havent been able to establish a clear pattern as to when the fuse blows. the one thing i can be fairly certain of is that the engine must be warm for it to blow. when i pull over to change the fuse after it has blown when the engine is warm it seems to go soon after i put in a replacement

 

Sounds like you may have a bare wire somewhere rubbing and shorting the fuse. Pull each item off the circuit one by one and see if the fuse stays good.Anything come up on the diagnostics??

 

Pull diagnostic codes as Cadsforfun suggests - how to here.