Blowing Fuses?

So my parking light fuse blew last night when i switched on the headlights, and forgot about it till i got pulled over tonight, went to the station and picked up some fuses, at first, replaced it with the same size fuse(the only one i had) and pulled the lights on, it immediately blew the fuse. Then put a higher amp fuse in and it blew it, and then another close fuse, and you'll never guess what happened. So i burned 3 fuses in a matter of 1 minute. What is wrong with my electrical system? I have an Optima Blue Top (the smaller one) and a 105amp alt from Napa... Also, i have an amp/sub wired up to the aux terminals on the battery and the inline fused worked on that setup, then one day decided to not take anymore fuses just like my parking lights, related?
Thanks for the help
Joe
^hates electrical gremlins

The parking light fuse and an inline fuse direct to the battery are not related. You really don't have much chance to trace something like this unless you have a multimeter. They are only about $10. Don't use higher fuses in a wiring system or you can melt down wires within the harness which will cause extreme electrical mayhem. I will also warn form personal experience not to use cheapo fuses like from the dollar store. I was using some of those and one (to my trailer lights) did not melt completely and caused wire melting that took me two weeks to straighten out.

what am i looking for exactly? bad ground? i do own a multi meter, but have never had to deal with something like this. sorry for the newb questions...
thanks
Joe

ok so i went out and took out the fuse, put the multi meter in its place, when the headlight switch is off, it shows no voltage, then if i turn it on, it spikes up to around 16v without the engine running(isn't this way too much?). What do i need to look for? I really don't know what i'm looking for so some help would really be great. Till this is fixed i cannot drive at night.
Thanks
Joe

You want to read the current going through the line, not the voltage... it'd give you a better idea what's going on.

more than likely u have a blown light bulb somewhere, start at one end of your jeep and check the light bulbs, when u blow a fuse u have a hot wire in the circuit going straight to ground, dont forget about the dash light bulbs as well, but i would bet it is one of the parking lamp bulbs just my .02

Yeah, 16V is too much. I am suspect of the meter. So if you just test the battery with the Jeep turned off, you get 16V too? Is there some other car around you can test too? Checking the bulbs is a good idea. You can take them all out and see if the fuse still blows.

Electric 101:

OPEN means no continuity in the circuit, things just don't work, but fuses don't blow as there is no load at all.

SHORT means that power is going directly to ground, fuses blow as the load is too much for the size of the circuit.

You are looking for a short. Bare wire, burnt out accessory, etc. Something is letting power go straight to ground--what we professionals like to call bad ju-ju.

i have a cheapo meter from OSH so i can only read up to 10A and when that happens the meter blows, and i don't want to do that. Ok i'll be sure to go through my lights, i'm hoping thats what it is,
Thanks
Joe

flyingbrick said:

i have a cheapo meter from OSH so i can only read up to 10A and when that happens the meter blows, and i don't want to do that. Ok i'll be sure to go through my lights, i'm hoping thats what it is,
Thanks
Joe

Click to expand...

Electric 101.1

How To Use a Multimeter

Video: http://www.youtube.com/watch?v=KzjMIcER4EU

Written: http://www.ladyada.net/library/metertut/index.html ***click on an item on the menu, then scroll down the page to see the info.