1989 Fuel pump problem?

[Guest mebeer89pathfinder]

Hi all,

I've got a prob with my electrical system. The battery drains constantly until it finally dies altogether. I had a used motor put in a while back and the fuse for the fuel pump kept blowing. I brought it back to the guy and he said he replaced the pump. It ran for a while, but now, when you turn the engine on, the battery drains and the car dies. I put a voltmeter across the battery terminals and had my dad pull fuses one by one. The battery kept draining for all of them except for when he pulled the fuel pump fuse. When he did that, the voltage started to increase across the battery for the few seconds it took the truck to die from no fuel being pumped. We repeated this a couple of times and the same thing happened. My question is, should I start with the fuel pump again? Or would it be in the wiring or the fuel pump relay? Any ideas would be appreciated. I already replaced the alternator so I'm pretty sure that's not the problem.

[denisb]

I'would have to say it's either your relay or something making your relay always energized. If you know where your relay is sittuated, Remove it and see if you still get voltage drop at your battery, if you do your problem is somewhere else.

 

If your problems goes away when you remove your relay check the following. A common relay has 3 0r 4 pins, only on of those pins should have power when the relay is disconected if any have power at all (this voltage should be checked with ignition off). To check for voltage measure from harness pin to a good known ground and ignition off.

 

One of those pins should have power when the ignition is turned on, this would be the pin that energizes your relay. (If you don't have a

 

This should point you in the right direction to check your relay. This is just a general way to check a relay circuit, but should work for your relay.

 

Hope this helps

[Guest mebeer89pathfinder]

Thanks for the help Den. Relay checked out Ok. Going to try replacing the fuel pump sending unit. Cross your fingers.............