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New fuel pump and starter relay problem...


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After installing a new fuel pump I noticed smoke coming from the starter relay while cranking the engine. Also I soldered  a ground clamp to the pump’s pig-tail and fastened it to the frame. 
I found where the smoke was coming from (see pic.)

 

Any advice would be appreciated. 

6DBBEF88-6A81-4B1D-9EF2-70B3E9F22199.jpeg

077A8FAD-E125-48C0-A2C9-9F355B5BFD3A.jpeg

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You have a short to ground and blew a fuse link, you will need to fix the short to ground before replacing the fuse link, also make sure to replace with another fuse link

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9 minutes ago, jdog said:

You have a short to ground and blew a fuse link, you will need to fix the short to ground before replacing the fuse link, also make sure to replace with another fuse link

So the ground wire to the fuel pump harness isn’t the problem?

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3 hours ago, Kickin’Chicken said:

So the ground wire to the fuel pump harness isn’t the problem?

I dunno, Just said it a short to ground, it could be that, it could be something else

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1 hour ago, zomeizter said:

From the picture, it looks like that black wire you soldered changes to orange at the connector, maybe that's a hot/power lead?

I agree. I disconnected that ground-to-frame jumper and the pump is buzzing like a carpenter bee. I’m thinking that black isn’t the ground after all (as I was told elsewhere.)

5ECECF60-368E-45DC-92C2-2B65F953AC17.jpeg

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1 hour ago, Kickin’Chicken said:

I agree. I disconnected that ground-to-frame jumper and the pump is buzzing like a carpenter bee. I’m thinking that black isn’t the ground after all (as I was told elsewhere.)

5ECECF60-368E-45DC-92C2-2B65F953AC17.jpeg

That plug looks backwards 😳

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1 hour ago, MiNi Beast said:

That plug looks backwards 😳

That's what I've been thinking. The ribs in the center of pump side I believe are the lock for the release clip which is on the other side. I don't know if the connector is purposely that far out, IIRC if you have the connectors reversed it won't go in all the way. 

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7 hours ago, WahooSteeler said:

That's what I've been thinking. The ribs in the center of pump side I believe are the lock for the release clip which is on the other side. I don't know if the connector is purposely that far out, IIRC if you have the connectors reversed it won't go in all the way. 

The lock and release clip are lined up and in place. You can see this in the other pic. I bought that at Oreilys. They said it was fit a Cherokee but was the same part for the mj 

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6 hours ago, scaleless said:

but that is probably the worst solder joint I've ever seen.

Ha ha ha!!!

I agree. It was hard getting the wires to hold in place, hold the soldering iron and solder on my back while reaching up under the truck bed. 
 

 

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Get your meter and/or test light and identify your hot, ground and fuel level sender leads and make sure the truck harness matches the pump pigtail connector (lead wise). You may have to bypass the fuel pump relay to verify the hot lead on the circuit. Get you some good wiring butt splices to repair the connection you worked on, there are some that will even solder, shrink and seal with just a heat gun. The crimp ones work too, just make sure they are crimped well and match your wiring size/gauge. If you run into issues and can't figure it out, you ain't that far from me, I could hook you up if you ain't in a hurry...

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52 minutes ago, Kickin’Chicken said:

The lock and release clip are lined up and in place. You can see this in the other pic. I bought that at Oreilys. They said it was fit a Cherokee but was the same part for the mj 

I reversed the black and grey wires and fastened the ground back on the frame to no avail. It burned the fusible link in two. So I’ve had problems with the ground to frame either way. 
 

Any advice would be appreciated. 
 

TIA

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33 minutes ago, zomeizter said:

Get your meter and/or test light and identify your hot, ground and fuel level sender leads and make sure the truck harness matches the pump pigtail connector (lead wise). You may have to bypass the fuel pump relay to verify the hot lead on the circuit. Get you some good wiring butt splices to repair the connection you worked on, there are some that will even solder, shrink and seal with just a heat gun. The crimp ones work too, just make sure they are crimped well and match your wiring size/gauge. If you run into issues and can't figure it out, you ain't that far from me, I could hook you up if you ain't in a hurry...

I’m ready when you are!!! Where are you located?

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3 minutes ago, cruiser54 said:

Could there be a mix-up in the wiring there?

I suppose so. I’ve had the black to orange (the way it lined up with the connector clip straight out of the box) and the pump ran unless I fastened the ground-to-frame pigtail. That caused the fusible link on starter relay to melt the orange insulation off the wire. 
Then I switched the black and grey wires in the new pump connector such that black went to black and grey to orange. I also connected the ground-to-frame modification and that burned the fusible link in two. 

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25 minutes ago, scaleless said:

This is the view under my truck.

20210611_110952.jpg

 

Black-black (ground)

Purple-brown (fuel sender)

Grey-Orange (switched 12v)

Interesting how the pump manufacturers use different colors for these three functions. Where did you buy your pump and who manufactures it?

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22 hours ago, Kickin’Chicken said:

I’m ready when you are!!! Where are you located?

I'm in Athens, but currently work has me in the bermuda triangle, I think I'm going home around the 20th...

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On 6/11/2021 at 11:56 AM, scaleless said:

I mean, it's not really the pump wires, it's the sender wires.  And that's an MTS sender.  MTS is the only aftermarket manufacturer for the fuel sender.

I think it depends on whether you have fuel injection or not. My 4.0 is fuel injected and therefore has a fuel pump in the tank. My Scrambler has a sending unit in its tank. 

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1 hour ago, Kickin’Chicken said:

I think it depends on whether you have fuel injection or not. My 4.0 is fuel injected and therefore has a fuel pump in the tank. My Scrambler has a sending unit in its tank. 

The pump is mounted to the fuel sender.  Both fuel injected and carbureted engines have a sender, the difference is fuel injection commonly uses an in-tank pump and carbureted applications commonly use a block-mounted pump, with exceptions.

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