For all the questions I try to answer here, I hope someone can answer mine

It goes like this. Put a good 15A engine fuse in (under the dash), turn key on. Turn key to start, fuse blows, tach and boost gauge drop and don't work. Then the electric fan in front of the radiator comes on. I can put a new fuse in with the key still on, and the fan cuts off, and you hear the relays underhood click.

It does this every time I hit the starter, it won't blow unless you turn the key. WTF is on this circuit that would make it do this? I tried unhooking the fan, but it didn't help. I hate troubleshooting electrical problems.

 

So you can have the key in the on position and everything is fine until you turn the key to the crank position?

If so you have either a short in the starter circuit or a bad starter. To trace, disconnect the starter wire at the starter. if it still blows, then you have a pinched or shorted wire. If it doesn't blow with the starter disconnected you have a bad starter.

 

The starter is fine. I've been all through the car with a multi meter and can't find ****

 

OK, here are a couple of possibilities. If the fuse you are talking about is the 15A fuse 2nd row down 2nd from the left, these things could be causing it. First thing, there is a 2-wire plug on the alternator (not the big wire). Unplug it and crank, if the fuse doesn't blow, bad alternator (in the inbuilt voltage regulator). It the fuse still blows, I suggest this: Turn off the ignition, jumper the fuel pump test connector (engine compartment passenger side 2-wire connector). Turn the ignition on (don't try and crank it). If the fuse blows, the problem is in the fuel pump circuit. It consists of 3 items: the circuit opening relay, the fuel pump resistor relay (If we're talking turbo), and the fuel pump itself. Locate the short and fix it. If the fuse doesn't blow, then it could still be a short in the start side of the circuit opening relay or the wiring associated with it. Hope this gives you a direction. Good luck!

Irv, Keith's dad

 

Thanks a lot! I wasn't sure what all was on that circuit, I didn't know what to check. The wiring diagram in the service manual is hard to understand.

It is the 15A fuse I was talking about. I just changed the fuel pump to a Walboro, but it did this on the stock pump. I was planning to rewire it with 8 ga wire from the battery, through the switch, and to the pump itself. I wonder if the fuel pump switch I put on the black/white wire on the rear shock tower could be doing it?

 

I agree with Keith... need to look at the two prong connector on the back of the alternator. Mine had cracked, allowing one of the prongs to contact the alternator body. Every time I turned the key... POOF!

Brian

 

That is probably it, the connector looke pretty crappy when I put the alternator back on the other day.

 

If you need a new one... there is another identical two pronger somewhere (I think near the front driver's side?) that you can swap. Use a small screwdriver to release the metal prongs (keep track of which is which) and just steal a good connector from another location....

Like I said, I think I stole a green one from an unused place on the front of my car somewhere.

Brian

 

If that doesn't fix it, you might check the round switching plug that is on the left end of the key cylinder (held in place by a single screw at the top).

The main fuse (100 amp) sends power to that switch that in turns sends power to the other circuits. In other words, if the fuse only blows when you turn the key, it might actually be the switching actuated when you turn the key thats shorting out.

I admit, this is unlikely. But it is a possiblility to check if all else fails.

Easy junk yard replacement if it is. One screw, 5 connectors. Whalllah.

 

I unhooked the relays on the front of the car, where the stock airbox would be. I unplugged the round white connector. It quit blowing the fuse. If these just run the fuel pump, I shouldn't need them since I am going to straight wire it from the battery, right? I guess I get to try it and see

 

Felix Wankel,

Yes, I would be Very, Very suspicious of the switch. It is highly unlikely that 2 seperate fuel pumps would be shorted. Does that switch have a black wire going to it? Is the case of the switch connected to one of the terminals? Either case could cause the problem.

Yes, you can wire the pump directly to the battery via a switch. Be aware, though, that you are bypassing the AFM switch, which would mean that in a collision the pump would continue to pump even after the engine quit, which could cause a fire! Check the teamfc3s.org site, I think, for a fuel pump rewire procedure that keeps this setup intact. If that is the wrong site, get back to me, I will find it for you. Good luck!

Irv, Keith's dad