Kickin’Chicken Posted June 10, 2021 Share Posted June 10, 2021 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. Link to comment Share on other sites More sharing options...
jdog Posted June 10, 2021 Share Posted June 10, 2021 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 Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 10, 2021 Author Share Posted June 10, 2021 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? Link to comment Share on other sites More sharing options...
MiNi Beast Posted June 10, 2021 Share Posted June 10, 2021 Pump looks like mine, i just used a nut. Link to comment Share on other sites More sharing options...
zomeizter Posted June 10, 2021 Share Posted June 10, 2021 From the picture, it looks like that black wire you soldered changes to orange at the connector, maybe that's a hot/power lead? Link to comment Share on other sites More sharing options...
jdog Posted June 11, 2021 Share Posted June 11, 2021 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 Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 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.) Link to comment Share on other sites More sharing options...
MiNi Beast Posted June 11, 2021 Share Posted June 11, 2021 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.) That plug looks backwards 😳 Link to comment Share on other sites More sharing options...
WahooSteeler Posted June 11, 2021 Share Posted June 11, 2021 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. Link to comment Share on other sites More sharing options...
scaleless Posted June 11, 2021 Share Posted June 11, 2021 Yeah, that is definitely backwards. Also no offense but that is probably the worst solder joint I've ever seen. Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 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 Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 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. Link to comment Share on other sites More sharing options...
zomeizter Posted June 11, 2021 Share Posted June 11, 2021 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... Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 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 Link to comment Share on other sites More sharing options...
cruiser54 Posted June 11, 2021 Share Posted June 11, 2021 Is that a new plug on the fuel pump side? Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 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? Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 1 minute ago, cruiser54 said: Is that a new plug on the fuel pump side? Yes sir! It’s new but now mangled. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 11, 2021 Share Posted June 11, 2021 Could there be a mix-up in the wiring there? Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 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. Link to comment Share on other sites More sharing options...
scaleless Posted June 11, 2021 Share Posted June 11, 2021 This is the view under my truck. Black-black (ground) Purple-brown (fuel sender) Grey-Orange (switched 12v) Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 11, 2021 Author Share Posted June 11, 2021 25 minutes ago, scaleless said: This is the view under my truck. 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? Link to comment Share on other sites More sharing options...
scaleless Posted June 11, 2021 Share Posted June 11, 2021 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. Link to comment Share on other sites More sharing options...
zomeizter Posted June 12, 2021 Share Posted June 12, 2021 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... Link to comment Share on other sites More sharing options...
Kickin’Chicken Posted June 13, 2021 Author Share Posted June 13, 2021 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. Link to comment Share on other sites More sharing options...
scaleless Posted June 13, 2021 Share Posted June 13, 2021 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. Link to comment Share on other sites More sharing options...
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