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No power to fuel pump

macgyvr

NAXJA Member #120
NAXJA Member
Location
NE Indiana
I have a 1988 MJ 4.0 auto 2wd.

I'm trying to figure out why there is no power to the fuel pump. If I put power to the pump it work.

There's no power to the plug.

I've checked the ground behind the tail light, I have ran a ground from the battery to the meter at the plug under the truck, no change.

There's no power to the plug under the driver's seat at the orange (I think that's the color) wire.

The float level works at the dash for fuel level.

There are 12 volts at the relay. The relay is working, I jumped it with no change.

I have wired around the ballast resistor with no change.

This truck has sat for 2 years. The fuel tank rusted out and the p.o. took the tank out. Prior to that it was his dd.

I'm not sure what to check next.

mac 'it's got to be something simple' gyvr
 
I didn’t think there was a fuse.

So im not sure what end to check from the plug?
 
Pull the fuse block halfs a part to makes sure nothings green and fuzzy, same with the big plug above the brake booster. This is where I bet you have no conection.
 
Have you inspected the c101 connector? The one I had you make sure was good inside the engine bay? Or the fuse box connector, the other one I had you make sure was good on the parts you sent me?

Sent from my SM-S727VL using Tapatalk
 
no, thats on tomorrows agenda i suppose...

one other note, in some google fu I found someone mentioned to make sure the dome light fuse was good...oddly this one was blown. upon doing some checking i found the glove box wiring harness to be a mess and fixed it, getting that circuit back in business...

i can't imagine it will fix my problem, but I'll check power to the plug tomorrow anyways...

mac 'because jeep' gyvr
 
Do the Renix have an ASD relay?

JIM.
 
Stupid question based on some of my stupidity. Is it possible you got the wires reversed at the fuel pump?
 
If you reverse them it runs but with inadequate pressure...cause backwards

My dewalt battery showed me this...

Theres no power at the plug in the cab under the drivers seat.

mac ‘ive failed this comanche’ gyvr
 
Might be time to call Nate.

JIM.
 
I called him before I even posted this...

I spent a couple of hours with howey on facebook messenger on Sunday night going over things and couldn't resolve it.

mac 'spent waaaaay to much time messing with it' gyvr
 
aa59542f8922cbbe2d8c42c1740327c5.jpg


Never figured it out.

Checked power...

Went through it with howey and the fsm

mac ‘fixed it my way’ gyvr
 
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