Dead Battery possibly Fuel pump, or relay

[jpo142]

Hello Everyone,

This morning my car battery was dead and read about .8 volts on a voltmeter. Another alarming aspect is that the ground cable, when disconnected from the negative post also was 0.8 volts.

I trouble shot everything checking and disconnecting cables until I was able to isolate the problem to the fuel pump rewiring kit power wire. With nothing else connected except for the power wire i got a short circuit, or diode checker steady beep from the power cable to ground.

My first guess was that the fuel pump died. I have a walboro 255. I checked the wiring and it looks fine. I also tried to measure the resistance across the contacts on the pump, with the pump disconnected. This was approximately a short of 1.0 ohm, and beeped with a diode checker. Is the terminal resistance supposed to be 1 ohm????

On a second note, the short from positive to negative went away when the plug to the pump was disconnected.

I went on to check the relay from the fuel pump rewire kit. I found that pin 30 is shorted to 87 and 87a , this seems bad. Also pin 30 shows continuity to pin 85.

30 = battery power
87 = normal off switch
87a = normally on switch
85 = relay activate
86 = ground

I am fairly sure that this relay is dead. Is my Walboro 255 dead too?

What ever happened, it did not draw a lot of current because the protective fuse on the re-wire kit is still good. But my battery is totally dead.

I have had the rewire kit and pump installed with no problems for three years and had just drove the car 2 days ago with no problems.

Thanks for all your help in advance,

Jim

 

[jpo142]

I have done some more testing and here is where I am:

The relay from the fuel pump rewire kit definitely broke.

I have taken apart just about every connection in order to try and locate the cause of this problem.

All cables to the battery and fuel pump are disconnected and isolated.

The MPI fuse is good, along with the battery fuse.

I believe there to be a short of some sort in the engine bay.

The white wires that connect to the positive terminal of the battery show continuity to ground with a diode checker. I have disconnected my alternator cables too. This is the strangest thing I have ever seen. With the ohm meter testing the white wires to ground i get an increasing resistance at around 70K ohms. But then i switch too measure volts and there is a decreasing voltage at around 200 mV and falling to zero. Its as if my multimeter is charging some capacitance.

When a car is completely isolated from the battery. are there any good resistance checks to help zero in on a problem.

Are those white wires, which are now disconnected, on the positive battery post supposed to have a continuity to ground???

Please help me. Any input is greatly appreciated. I would like to see my Mom on mothers day.

Thanks,

Jim


more info:::!!!!!!

The white wires are drawing 170 mA of current when I placed a Ammeter in series from the battery post to the white wires. My battery is currently at 4.75 volts

Positive post -----> ammeter------> white wires------> white wires NOT connected to Alternator !!!
I know for a fact this is bad.
I also tried to see if my fuel pump will turn on by directly applying the 4.75 volts with no luck. Is 4.75 volts to low to get any action out of the pump. I tried to activate my old stock pump too and that did not work either on 4.75 volts.