Hi all,

First time poster, long time reader. In my past, I restored classic muscle cars (68 camero, 70 Chevelle SS LS5, 67 El Camino etc), so I'm not new to wrenching

Daughter has a 2001 Neon Se automatic, 125,000 miles. I rebuilt the engine after she broke a timing belt (it has been changed, but the shop didn't change the tensioner, it broke of course!). The car ran great after rebuild; she's put ~ 6000 miles on it with no problems. A few days ago, the car died, would not crank. Checked fuses and found # 21 in PDC blown, replaced the fuse and the car started right up. The fuse blew again when the car was put in reverse / under load.

Looking at the electrical schematic (8W-30-10, it shows the fuel pump relay, PCM, and fuel pump module. Pulled and checked the fuel pump module, no problems there; I get good pressure at the rail etc. Checked the fuel pump replay, no problems there either.

I have a spare PCM and will swap that next; but I'm still bothered by the fact that the car starts and runs fine until it's put in reverse, then the fuse blows (under load). Thinking speed sensor, but it's not associated with the fuel / fuse #21 electrical circuit except for the ASD relay and PCM.

The knowledge base here is awesome, hoping someone has had the same issue.

Your thoughts are appreciated!

 

maybe check under the center consol for a wire grounding out or something. theres a computer under the shifter. hope i can help.... i hate electrical...good luck

 

According to the FSM, fuse 21 goes to the fuel pump relay, ASD, PCM and Data Link Connector.
The PCM is tied to both fuse 21 and the ASD and the ASD connects to the PCM via a DG/OR wire. I can't see why the fuel pump relay or DLC would blow the fuse while going into reverse, so I'd look at the ASD/PCM wires for breaks and/or grounding out. Unfortunately, the ASD has a lot of stuff connected to it (though not as much in 03-05 Neons), so you just have to kinda go through everything.

However, I have also heard of frayed/broken alternator (on a 2003 though) and O2 sensor wiring causing fuse 21 to blow as well.

https://dodgeforum.com/forum/2nd-gen...1-blowing.html

 

With the fuel pump disconnected, the fuse still blows which also means the fuel pump relay is good. Gotta be something grounding on the down side of fuse #21/ ASD. I'll chase the RD/WT wires via meter and see what I can find. The wire harness on these cars suck, but the schematics are good.

I actually have fun working on this car. Like I said, the design is good, the execution isn't so good.

 

Took the logical route by disconnecting all components that feed to the ASD. Reconnected each component one at a time and attempting to turn the engine over. Last component to check was the noise suppressor, bingo, blew the fuse when the key was turned to on. Good ole DG/OR wires. The actual wire connected to the noise suppressor was frayed (behind spade connector) and would touch the head grounding the circuit. Working back, the wire goes to the ASD and then to PDC fuse # 21. Better to blow a fuse then short the PCM.

At least it was a cheap fix.

Thanks for all the help, very appreciated!

 

Yup yup! Good to hear you got it fixed!