amp88

I have a 2000 chevy van ,6cyl,,,fuel pump isn't kickn in but I hear a loud clickn comin from relay in front ,and if touch it while turning key on u feel it on the relay box ,,could that be the issue

canucklehead

Swap the starter and fuel pump relays. They are side by side. If you hear the fuel pump prime when the key is turned on but the engine wont crank...then yes. Its the relay.

JJTech

Do yourself a favor and try the easy stuff first. I was about to drop the fuel tank in my trusty old 1996 express 1500 when I discovered a dirty connector.

I had recently replaced the oil pressure sender which blew through with oil and indicated zero oil pressure. A few months later the van died a few times with no fuel pressure. I put a paper clip across the oil pressure switch connector and the pump didn't turn on even though I measured 12 volts at the paper clip. I either had a bad pump or bad wiring to the pump. I pierced the wire in the harness about a foot from the pump to check the voltage, and while I was messing with it the pump turned on. Sure seems like a bad connector now. Fortunately I was able to reach the connector on top of the tank so I pulled and cleaned it with tuner cleaner. The van started right up and ran down to the end of my long dirt driveway and then it died in the middle of the road.

I managed to get it to start a few more times to get it back to the garage. While preparing to drop the tank, I went ahead and pulled that top connector off again and measured the voltage at the connector while the paper clip was providing the circuit from the oil pressure switch connector. Open circuit measurement was only 7 volts on the grey wire even though it was 12 volts back at the pressure switch. Now I knew I had a bad resistive connection, or splice somewhere. I traced the harness towards the front looking for splice S138 which seemed to be the only other link in the chain. In the diagrams, the connector on the top of the tank appears to be C301, but there is actually ANOTHER connector attached to the front of the tank, very exposed to the elements. THAT one is C301. I pulled it apart and it looked OK, but the contacts were a little dull as compared to the other one. I sprayed the heck out of it with tuner cleaner and shoved it in and out about 10 times, and now I have a solid 12 volts Van runs like a champ now. So glad I checked the voltage again before I started shot-gunning parts. I wish these GM wiring diagrams referenced the actual connector and splice locations, that would save a lot of wasted time.

JJTech

One more note. To make sure, I wiggled that C301 connector in front of the tank while the paper clip was running the pump. The pump would change sounds and cut out every once in a while which means the contacts are actually bad or a wire is broken. Guess I will have to actually replace the connector.

Carpenter13

Hey, I've been having the same series of issues, and I agree that I have narrowed it down to the connector at the front of the tank, have you found a replacement for it? I haven't been able to find anything other then the connector on the pump.
Thanks in advance

JJTech

Yeah, the connector contacts were corroded and I decided not to replace it. Just using contact cleaner didn't work. I cleaned the female contacts with jeweler's screwdriver of the right size sprayed with contact cleaner and then used a heavy safety pin to shrink the contact hole a bit. I also scraped the male contacts really well. I plugged it in and out a few times and crimped the hole one more time. I tested it with the paper clip while shaking the wires and it sounded fine. It has been working perfectly ever since. It is in a bad place for road spray. I would recommend wrapping it with waterproof tape to keep out the elements. Also use zip ties to hold the tape and keep the connector in place.

Carpenter13

Excellent, thanks, I'll try that. I've been struggling with this for a few months now, I've even replaced the pump twice, because it seemed like the rubber hammer to the tank trick was successful when it wouldn't start. The last pump I got from the dealer, I've replaced the pump end of the wire harness, and I'm still having issues. I haven't let the tank get below 3/4, so I find it hard to believe the pumps keep failing. The tank was clean, I have a new fuel filter, I have good pressure when the pump is on, so I'm seriously running out of ideas. The other night the pump wasn't coming on, and I wiggled the front connection, and it did start after that, so I'm thinking I'm on the right path. If I could replace it I would, but I can't even get that part of the harness from the dealer. Occasionally the gauge acts weird too, so that supports the plug theory as well. I'm glad to talk to someone with a similar problem, and happy that you had success, hopefully I will too. Thanks!

josh heck

ecm b is the fuse that powers the pump

tireman9

If you trace your problem to a bad relay you might want to review THIS post and consider filing a complaint with NHTSA (link in the post)
as this may be a defective part problem.
NHTSA can order a recall but there needs to be a number of complaints on file.

Theo Tash

Check the ground for the fuel pump on the driver side frame rail all the way in the back it gets Rusty and loses ground