Fuel Pump/wiring problems

Rapley · Post by **Rapley** » Thu Aug 02, 2007 7:16 pm

Here's my problem, and a fair bit of reading. I know it's not a 2gen, but I figured it's all very similar. My car's a 97 Dodge Neon, DOHC, 5spd.

Car wouldn't start the other day, would keep on turning over, but not fire up. Couldn't hear the fuel pump coming on, so I figured it was a shot fuel pump. I got the car towed home, and today I checked the fuel pump fuse (20A mini fuse, circled in RED on wiring diagram), and it was blown. So i replaced it with a new one, and i turn the key forward (not even attempting to turn the car over) and the fuse blows. Here's a wiring diagram (clickable):

I've disconnected my fuel pump, and the fuse still blows when I turn the ignition on, so I know it's not a short in the fuel pump itself.
I've checked the fuel pump relay (by switching it with the horn one) and it's fine. I also checked the Automatic Shut Down Relay, and it was fine.

So to try and eliminate the paths where the short COULD be I did these tests:

I left the fuel pump disconnected, pulled the fuel pump relay and the auto shut down relay out. I then turned the ignition on, and the fuse DIDN'T blow.I figured this eliminated the connection from the fuse to the PCM (Red/wht wire on diagram). So, I stuck the fuel pump relay back in, and tried again, the fuse DIDN'T blow. I figured this eliminated the connection from the Fuel pump relay to the PCM, and the connection from the Relay to the fuel pump itself. I then proceeded to plug in the fuel pump, and the fuse DIDN'T blow, this eliminated the fuel pump itself as the problem. I then put in the auto shut down relay and the fuse DID blow. So, to be clear, I'm pretty sure I've eliminated the fuel pump, the fuel pump relay, the connection from the relay to the pump, and the connections to the PCM from the fuse, and the fuel pump relay to the PCM.

My real problem is, there's ALOT of things controlled by the auto shut down relay (which seems to make my fuse blow), and i have NO clue where to start to look for wiring problems/shot components in this circuit. I don't know what the Noise Suppressor (in ORANGE square) is, or where it is located in the engine bay, so if someone could point me towards that so i can eliminate it as the problem, it'd be great.

TO SUM IT UP:

Fuel pump fuse keeps blowing when I turn the ignition on (not EVERY time, even under the same circumstances, IE: no relays out, things unplugged etc).

It's NOT:

Fuel pump
Fuel pump relay
Fuse to PCM connection
Relay to PCM connection

It DOES:

Blow when the Auto Shut down Relay is IN
Not blow EVERY time under the same circumstances, but when I crank the car over, it will.

Any suggestions? Are there any problem components/areas that cause this fuse to blow? I'm kinda stumped, and just hope I don't have to go tracing every wire that is related to this Auto Shut Down Relay <_<

Thanks

Josh

aperson · Post by **aperson** » Fri Aug 03, 2007 1:21 pm

Sorry I don't have a clue as to what could be causing this, but there's a 1gn.org too that you could try.

Rapley · Post by **Rapley** » Sat Aug 04, 2007 12:44 am

Yup, already posted on neons.org, and neoncanada, just trying all the places to see if anyone has a solution.

gilly02le · Post by **gilly02le** » Sat Aug 04, 2007 3:13 pm

I had my car do this same thing to me... cept mines a 2gn.. but anyways.. what happened was, my lower o2 sensor, melted itself and was grounding out on the cat, causing the car to either die randomly after sometimes a few minutes of driving, and sometimes it would do it as soon as started, and i would have to change the fuse,(which almost always blew right after) Turned out my o2 sensor was shorting out, and causing my asr to shut off the fuel..

if you can get to it, try unplugging the lower sensor and see if the car will start/run..

Rapley · Post by **Rapley** » Sat Aug 04, 2007 3:16 pm

Yeh, I've been reading up on the other .org and apparentally 1gens have a problem with the downstream O2 sensor shorting, but i inspected mine and it was fine. So i'm running, but still know there's a problem somewhere that's gunna bite me haha

gilly02le · Post by **gilly02le** » Sat Aug 04, 2007 3:38 pm

i see, have you unplugged the lower sensor and driven around for a bit.. it might be shorted internally..

blue demon02 · Post by **blue demon02** » Sat Aug 04, 2007 4:37 pm

Good luck its a short somewhere and finding it will be a real bitch. I would save your self some time and probely money and just replace the harness/ECU. Might even need to replace the fuse box too.