Weird fuel pump issues on 97 dodge ram! Please help!

Maintenance/Repairs
1

Hello! I have a 97 Dodge Ram 1500 5.9 4x4. Some weird stuff has been happening with the fuel pump and I’m stumped. Here’s the story…

I was driving and suddenly the engine cut out. Electrical on, but engine just dead. Stuck on the side of the road I could crank just fine and maybe get it to sputter and run super rough and then die. Mostly wouldn’t start at all. Luckily I had a friend in the car and we figured out if I bang on the gas tank with a mallet while she turned, it would start, run for a few miles, and then it would happen all over again. After this happening 3 times I finally got home. (Weirdly I could never hear the pump turn on while turning the key half on while stuck on the side of road - doesn’t mean it wasn’t, but maybe this info will be useful…)

I have now replaced the fuel pump, but now am not getting ANYTHING. The previous banging method does not work. I have put a power tester light on to each of the connections in the power harness and it does not light up, not even for a second when I turn the key. So it seems new pump may be good but it’s not getting any power? But then how was the pump running before if even for a few miles all the way up until I replaced the pump? I switched the relay out with horn and relay works, I tested where the relay plugs in and it is getting power.

Any ideas??? Thanks!

2

Does the new fuel pump have a good ground? Needs to be essentially zero Ohms to work properly.

3

You need to test the power to the pump with the pump in the circuit and it should be running. You seem to have a bad connection to power going to the pump. If the ground to the pump is bad you will have voltage on the ground connection due to the unwanted resistance in the ground connection. If the problem is on the hot side the voltage will be significantly less than the battery voltage. Just be sure when you check the power your meter has a known good ground connection for reference.