fuse 1 keeps blowing

[pickupman6]

So yesterday I went to pick up a friend to take him to the dr and about a mile down the road my car cuts off try to crank it and it just spins and spins. Check fuses and #1 is blown. Replaced it, fired right up. Took my friend to the drs but I noticed every so often by battery light would flicker, I just replaced the alternator last year but it came from autozone and my warranty went out about 2 months ago so it wouldn't surprise me if the alternator was the problem. But anyways, on the way back from seeing the dr it quit again. Replaced fuse and it fired right up again. And it quit on me this morning once during my 40 trip to work and didn't give ma a problem on the way home other than the battery light flickers once in a while. Btw I'm driving on new smooth asphault when it quit this morning so there was no jarring that coulda caused it to short. Just wondering if this has happened to anyone before and what the problem was. Also I would like to hear some ideas of what it could be. I gotta pick up a new multimeter this week, dang same friend I carried to the dr left my old one out in the rain:(

[pickupman6]

Forgot to add, how many amps should a good fuel pump draw?

[carotman]

try unplugging the alternator and see if the fuse still blows

[pickupman6]

Thanks for the reply. I already tried that. Drove around all day yesterday and it didn't blow. Plugged it back in and today it still didn't blow. I've put over 60 miles on it today with no problems. I inspected the plug when I unplugged it and it looks fine with no broke or loose wires. Oh well, we'll see what happens. But it usually popped within 10 to 20 miles.

[Rendon LX-i]

Good fuel pump will draw 8amps and if lower then 5 its shot rule of tumb wise it will run but lean as hell and cause to car to turn off ever now and then loss of power. ill have to pull the specs up . but using a basic volt meter with quick refresh rate is needed.

I would put a fuse in and have the car running and do a shake down test meaning what ever that circut is controling you have to grab that harness and move it as much as you can if you see a miss fire or stumble exc lights flicker even car shut off thats your problem. has to be a wire shorted to ground or its contacting with other circut causing it to overload and blow that fuse.

[pickupman6]

Thanks rendon. I will check that out later this week.

[pickupman6]

Well just un update, I forgot that I was out of 15a fuses so I stuck in a 20a and it never blew once, found some more 15a fuses stuck one in and it blew on the way to the store replaced with another one and it also blew after about 20 minutes. When I got home I stuck a fresh 15a in there and let it idle for about 25 minutes before it popped. I know I need to pick up a multimeter, but I'm thinking its the fuel pump drawing too many amps since I can not get it to blow a 20a fuse. I did the jiggle test and never could get it to pop that way so I don't think its a short. In my first post I mentioned the battery light flickering every once in a while but I haven't experienced that since then. I'm thinking that was unrelated since I've been having problems with this alternator for a while (at high rpms the light comes on, and as tim has posted in many of the other alternator threads that is cause the brushes ar wore down and they lose spring pressure so the centifigul force pulls them off the comutator).