[Stinkin_V8]

Well, this isn't a hotrod, but as soon as I can fix my wife's car here, I can get back to my project(s). Electrical troubleshooting is definately not my strong point.

'91 Dodge Shadow, 2.5L manual with EFI.. Suddenly died last week, I towed it home and started poking around. No spark from the ignition coil so I replaced it and later found one of the fusible links was shot. It's the one that comes from (or goes to?) the fuel pump relay. The fuel pump fuse in the fuse block is fine. I put an ammeter in line, it was drawing 9 amps, so the 20 amp fuse in the panel made it seem like all was fine. I replaced the fusible link with a 20A inline fuse because I wasn't confident I'd found the problem. Drove it a few miles and no problems. Went out later (car had cooled) to run to the store real quick and just out of the driveway it started revving really high and then died. I replaced the inline fuse again and it just keeps popping as soon as the key is on.

The only real load on the circuit when the key is on (engine not running) is the fuel pump. Is it possible for an in-tank fuel pump to intermittently draw enough of power to blow a 20A fuse? I'm thinking it isn't the fuel pump since the fuse in the fuse block hasn't blown. Anyone have any ideas?

[BstMech]

I recently had a problem on a Caravan about the same year. It blew the fusible link to the automatic shutdown relay. The wiring harness was rubbing the firewall and wore into the wire just after the link. The link was blowing/burning but the fuse was fine. I would check the harness just after the fusible link for chaffing/damage.

[Stinkin_V8]

Thanks BstMech,

I inspected the harness forward of the fusible link, it goes to the fuel pump relay and to the SBEC. All looks fine. There is a loop back into the harness toward the firewall that I really couldn't get to very well. I'll try having a look in there.

I was leaning toward a faulty fuel pump, but I wouldn't expect it to fail in a way that would draw huge amounts of power through it and start pumping a lot of fuel (I assume that was the cause of the high revs)

[dmorris1200]

Try unplugging the fuel pump connector. If the fuse still blows short is before the pump in harness somewhere.

[Stinkin_V8]

Good thought, dmorris1200.. I tried that tonight. I tried combinations of disconnecting the fuel pump relay and the SBEC while the pump was disconnected. Once I plug in the fuel pump relay, the fuse blows. Even tried a new relay (standard bosch-style, had one kicking around)

The relay closes a circuit from the fusible link to a green with black striped wire. I'll have to start tracing that wire from the relay to see where it goes. I think that's my culprit.

[Stinkin_V8]

I found it. Worn insulation was the cause. I had to cut open all of the wiring harness to find it - it started at the pump relay on the left fender, back ot the f'wall, around to the right side and then under the air cleaner. Thanks for the tips, guys.