Fuel Pump Ballast Resistor Questions
#1
Member
Thread Starter
Constant Rear Humming Sound
Hey guys,
hoping someone has dealt with this issue before.
I have a 92 laredo cherokee with a towing hitch and 7 pin wiring attached. when I turn the key to turn the electricity on inside the car (without starting the engine) I hear a noise for a split second in the rear of my car like something machine/ electrical like turned on. When I actually start the engine and am driving the car, that noise becomes constant. It's a pretty loud humming sound. I thought it might be something with the wiring harness for trailer power adapter, however when I put my ear to the back inside the trunk, it seems like the noise is actually coming from underneath the car near the rear skid plat and differential. What is this sound? Is this perhaps normal? Any help would be much appreciated.
Happy new year
hoping someone has dealt with this issue before.
I have a 92 laredo cherokee with a towing hitch and 7 pin wiring attached. when I turn the key to turn the electricity on inside the car (without starting the engine) I hear a noise for a split second in the rear of my car like something machine/ electrical like turned on. When I actually start the engine and am driving the car, that noise becomes constant. It's a pretty loud humming sound. I thought it might be something with the wiring harness for trailer power adapter, however when I put my ear to the back inside the trunk, it seems like the noise is actually coming from underneath the car near the rear skid plat and differential. What is this sound? Is this perhaps normal? Any help would be much appreciated.
Happy new year
#2
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Year: 1995 RHD
Model: Cherokee (XJ)
Engine: 4.0l
From your description I would say it sounds like your fuel pump in the tank. I do hear mine when turning the ingition on but not when the engine is running.
#4
Member
X3 on the in tank fuel pump. If this is a new sound that you have not heard previously it may be a sign of impending pump failure.
#5
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Thread Starter
#6
Member
A ballast is unlikely. A pump is the much more likely to be the source of the noise. I have had electric pumps start making noise and fail soon after. Again, if this is a new noise that you have not heard previously, plan on replacing the pump soon.
Last edited by Steve Hayes; 01-01-2020 at 07:48 PM.
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#8
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#10
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Fuel Pump Ballast Resistor Questions
I've just inspected my ballast resistor and the two plugs that attach to the prongs of the resistor are terribly corroded. What is the technical name of those two plugs? Where can I buy them?
thanks!
thanks!
#11
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Year: 1989
Model: Comanche (MJ)
Engine: 4.0
I believe standard insulated 1/4" female spade connectors will fit. Hardware or auto store in the electrical section should have them cheap in a variety pack. Use a blob of silicon grease on them to keep the replacements from corroding since they're somewhat exposed to the elements. I don't recall the wire size. 16 or 18 gauge would be my guess.
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AlSpeciale (01-07-2020)
#12
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
I don't have a ballast resistor on mine, so I can't check for you, but I think you are looking for a 1/4" spade terminal. https://www.delcity.net/store/Push!O...inals/p_801898
If you want cheapos, any hardware or auto parts store will have them. Don't get cheapos. Get good quality nylon insulated fittings ( and use https://www.delcity.net/store/Ratcheting-Crimpers/p_10382(also or even https://www.lowes.com/pd/IDEAL-Non-Insulated-Insulated-Terminal-Crimper/999960629). Don't use those https://www.delcity.net/store//Crimping-Tool-&-Wire-Terminal-Kits/p_802248, and do NOT use pliers!!!!!
If you want cheapos, any hardware or auto parts store will have them. Don't get cheapos. Get good quality nylon insulated fittings ( and use https://www.delcity.net/store/Ratcheting-Crimpers/p_10382(also or even https://www.lowes.com/pd/IDEAL-Non-Insulated-Insulated-Terminal-Crimper/999960629). Don't use those https://www.delcity.net/store//Crimping-Tool-&-Wire-Terminal-Kits/p_802248, and do NOT use pliers!!!!!
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AlSpeciale (01-07-2020)
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AlSpeciale (01-07-2020)
#14
Newbie
The fuel pump runs just fine without the resistor. Connect the wires and you are good to go. I did this on my 1990 XJ a few years ago and no problems encountered.
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AlSpeciale (01-07-2020)
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AlSpeciale (01-07-2020)