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**nitrofarm** · 12-10-2011, 09:01 AM

When you say you disconected the Fog lites/Amp.How did you do that? Did you pull the fuse's (this would be the correct way). You did fuse them all, right? Sounds like you may have a main wire shorting to ground.Get a cheap meter and do some continuity tests.

**crazyrog17** · 12-10-2011, 09:27 AM

My dads car is doing the exact same thing. He will replace the main fuse and it will pop when he's driving to work. We tested the output of the alternator at around 13.8v and the only accessories running are the hvac blower and exterior lights. Where should we start looking for trouble?

**FestYboy** · 12-10-2011, 10:23 AM

fuses don't blow because of voltage across them, it's be cause of CURRENT draw across them (that's why they're rated for AMPS). typicaly, a fuse in any circuit will be rated at TWICE the nominal load (i.e. a 30A seat belt fuse usualy only sees 15A when loaded). Darlo, you've gone from the 30A main rating to almost doubling that with a 50A main and still blowing it... that's a BIG red flag. First, you AMP should be seperatly fused straight from the battery, as well as all accessory lamps and controled by relays (also fused). you need to find the NON stock accessory that is causing the high draw and eleminate it. get a large collection of 20A main fuses and start eleminating other fuses and accessories and also visualy check for freying and burn throughs to bare metal that can cause a dead short. remember, at 50A, you're arc welding!!

**Movin** · 12-10-2011, 01:57 PM

Check the wiring diagram with 3 fusible links shown leaving the battery. The diagram in our sticky. It sounds like you wired the lights and alternator together instead of as shown.

The way you have it wired would work fine until the battery asks for a little bit more to charge back up. This compounded by fuses..they quick blow as opposed to a fusible link that will slow blow. The alternator should be capable of 50 amps output minimum at speed, if the battery asks for more than 30 for even a second the pretty blue light will flash!

**Darlo** · 12-11-2011, 04:18 AM

So just to clarify, even after disconnecting the fog lamps and sub/amp from the battery terminal connections (which is where I had them hooked up, if that is bad, please mention this), I STILL blew the 40A fuse! I did NOT however blow the 50A fuse after cleaning the metal that the fuse clips into (may not be related, as I dont think a fuse would blow due to a bad connection).

ALSO, when I blew one of the 30A fuses, by dome light blew too, as there seemed to be a power surge, right when the fuse blew!

This sucks, as all I really want to do is have some nice fog lamps, lol!

**crazyrog17** · 12-11-2011, 08:14 AM

I don't want to derail the thread but we have the same issue. The main fuse is blowing...

On this car, the dash lights illuminate brightly and the engine speeds up for a hot second until the fuse pops. The engine still runs after the fuse blows, but I'm assuming its off of the battery's power.

The only thing I can think of that might have caused this was grounding the one wire connector in the engine compartment to adjust the timing. I didn't have this problem until we messed with that.

**Movin** · 12-11-2011, 10:24 AM

Do you have the proper wires to the new fuses ? The problem should be under the hood. check it while it is cold =put it outside, then see what wire gets warm. If its frosty it should really easy!!

**FestYboy** · 12-11-2011, 06:19 PM

Originally posted by crazyrog17 View Post

I don't want to derail the thread but we have the same issue. The main fuse is blowing...

On this car, the dash lights illuminate brightly and the engine speeds up for a hot second until the fuse pops. The engine still runs after the fuse blows, but I'm assuming its off of the battery's power.

The only thing I can think of that might have caused this was grounding the one wire connector in the engine compartment to adjust the timing. I didn't have this problem until we messed with that.

replace the fuse and then connect a multimeter to the battery and watch the voltage untill the fuse blows again. i suspect you've got an alternator that is not being rectified or regulated. you would realy want to have 2 DVOMs running at the same time so that you can watch AC AND DC voltage. if it's unrectified, you'll see high AC voltage (over 0.2vAC) and the DC voltage will be clost to or OVER 16vDC if unregulated.

**nitrofarm** · 12-11-2011, 08:09 PM

Originally posted by Darlo View Post

So just to clarify, even after disconnecting the fog lamps and sub/amp from the battery terminal connections (which is where I had them hooked up, if that is bad, please mention this), I STILL blew the 40A fuse! I did NOT however blow the 50A fuse after cleaning the metal that the fuse clips into (may not be related, as I dont think a fuse would blow due to a bad connection).

ALSO, when I blew one of the 30A fuses, by dome light blew too, as there seemed to be a power surge, right when the fuse blew!

This sucks, as all I really want to do is have some nice fog lamps, lol!

Yes a fuse can blow from a bad connection.The circuit will generate more heat becasue of the extra resistance. You might want to look closely at your fuesable link block for green corrosion.

**93festarosa** · 12-11-2011, 08:24 PM

Why doesnt everyone do away with the fusible link box and just wire up and use regular fuses? Im just curious is there reasoning behind keeping the fusible link box?

**Movin** · 12-11-2011, 08:57 PM

Your fuse conversion is way cleaner than factory. Ford has a TSB for bigger links and a protector for the wire loom near the coil..just because they always have had a lot of problems. Fusible links do not pop as quick as a fuse and are less likely to have a poor connection if they are installed right. Read like you did on your fuses only using new fusible link. The factory job was horrible.
Nice job!

**nitrofarm** · 12-11-2011, 11:05 PM

I just realized something. You were running 2 sets of fog lites & a Sub Whoofer amplifier off the Battery.
Thats all fine & good with fresh wires.But your wires arent that good.The connections in the engine bay get corroded over time.Then when you start pulling @ 50a through them.You have a lot of heat build up @ that corroded terminal. You may have melting wiring insulation @ the Dist block. If you want to pull that many amps.You definitely would benefit from a wiring upgrade. I don't know how many amp fog lites you are using.But some are equipped with 35a fuses. So lets just they are pulling @ 10-15a each.Plus your Sub Amp is pulling what,another 10-15a? It doesn't take much to figure out.That your reaching the capacity of your alternator,when running other accs like blower & headlites etc . Not putting you down for doing this,jus saying.

**iceracerdude** · 12-11-2011, 11:15 PM

check the big wire that runs down to the alternator (at the alternator) for a good connection. That the wire is still clamped securely in it's connector, and then that the connector is securely fastened to the alternator with that 10mm nut.

**Darlo** · 12-12-2011, 12:44 AM

Ok so an update......

I hooked everything back up (fog lamps and sub/amp) and put in a 30A and drove for a good 5min before it blew, and when I went to put back in the 50A, I noticed something interesting. When I push the fuse all the way in, there is no connection, but if I pull it out a bit it will work. I went and slowly pulled it in and out and noticed the dome light was brighter at some spots than others.

I can only assume from this that I need to either majorly clean up that fuse "box" or wire a new one up all together. Is this easy to do? What is the best way to go about it?

Also, if I am on the wrong track, please let me know.

Thanks

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MAIN FUSE BLOWING! HELP!

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