Ok ill describe this the best I can. I do not have much knowledge at all about electrical so maybe someone can help me. I have a 2000 ss m4. For some reason when I hit a low spot in the road my fuel pump fuse gets popped. The car is lowered, and the issue started after I accidently bottomed the front of the car out in a drive way on a gravel back road. Did not seem to do much damage from what I could tell, I took off down the road and about couple hundred yards the car died. After towing it, the next day is when I found the fuel pump fuse blown. I replaced the fuse and drove the car for about a day or two. Then while driving down a slightly rough road, I hit a low spot. Didnt really bottom out but kind of a rough jolt. As soon as that happened the car died. Another fuse blown. After changing it I started the car and punched the gas and blew it again. Then after changing it again, as soon as I would turn the igntion switch it would blow the fuse. It did that over and over. So I sat there for maybe an hour, and the car up and started. I looked over the bottom of the car and under the hood and I can not seem to find any bare wires or anything shorting out. So I stuck a 25 amp circuit breaker in place of the fuse and have not had any issues. Can anyone help me on this?
Now another question..
I had dropped the kick panel and was checking out the wiring to see if something under there could be causing my issue. I let the car idle and I gently pushing the wiring around, trying to see if I could get it to pop the fuse. Found nothing. I got in the car and took off and starting having a/c issue. When you give the car gas, the ac blows through the defrost. When you let off or keep an even speed it blows through the vents like it is supposed to. I checked the vaccuum lines I could find under the hood and couldnt seem to find any cracked lines.
Im really lost on these issues. Ive only had the car about two months, and am decently mechanically inclined except for the lack of knowledge on electrical. When I rebuilt the steering column and dropped the kick panel there is a ton of wiring. Some after market security system, which isnt hooked up. It truely looks like a mess under there. And I dont know where to start.
Sorry for typing a short novel, but im trying to explain the issues the best I can.
thanks.

 

First, take that out. You can cause even more damage.

Find a friend, or someone on here, with the schematics for the fuel pump circuit. Then start tracing wires. Check all your underhood grounds. Also check for fuel leaks, since you bottomed out.

 

Didnt even think about that. Where I work they have all data, so I should be able to get them to print off the schematics. Is there also a schematics for the grounds? Im new to these cars so I would not know where to start on looking for the grounds. I appreciate the advice.

 

Does this happen when your fuel tank is full? Has it been hear empty?

 

If you leave that 25 Amp C/B in, you'll likely find your short-circuit in the way of a ball of flames or a melted wiring harness. Remove it now! The fuse is blowing because your hot lead is shorting out. If it happens when you bottom out, I'd start with your wiring harness from the rear of the vehicle. Check for any kinks or bare wires near your suspension.

 

Or... if the fuel level sensor is bad, the whole car could go up in flames! (Call me crazy, but I really don't like sparks in my gas tank.)

 

Well Im glad you guys mentioned that. My sending unit is bad. It does not read accurate. It will be on empty, then jump to full. So it is hard to tell if it is happening close to empty or not. I looked under the rear of the car. I did see where there were a couple connectors plugged into a board or what ever you want to call it. The wires running to it seemed fine. I havnt dropped the tank to and chased the wires up to the pump tho. If I knew how to post pics I would post pics of the wiring under the dash, and a couple other areas I have been concerned with. Maybe someone could help me with that? I would be posting the pics off of my phone.