Ryno Posted June 17, 2019 Posted June 17, 2019 I would be grateful if someone could help me identify what this part circled in the picture is. I was replacing my vacuum harness and realized that it was not there, as in gone completely. Screwhole is there but that is it. FYI, I come across this image in another forum here, not mine. Accidentally closed my browser before I could remember who`s it was.
eaglescout526 Posted June 17, 2019 Posted June 17, 2019 That’s the fuel ballast resistor. It’s there to quiet the amount of noise the fuel pump produces. Most everyone here bypasses it unless you want original looks to your truck
DirtyComanche Posted June 17, 2019 Posted June 17, 2019 I leave them installed. I don't fully believe they were just there for noise. It is a very reliable part, and makes it easy to quickly disable the truck if need be.
eaglescout526 Posted June 17, 2019 Posted June 17, 2019 That’s what Chrysler was putting them there for. Many people complained about pump noise in the cabin on the XJ and that was the remedy for it. It’s also a quick bypass, not really a way to disable the vehicle unless someone knows what they are looking at.
DirtyComanche Posted June 17, 2019 Posted June 17, 2019 4 minutes ago, eaglescout526 said: That’s what Chrysler was putting them there for. Many people complained about pump noise in the cabin on the XJ and that was the remedy for it. It’s also a quick bypass, not really a way to disable the vehicle unless someone knows what they are looking at. Pump noise or pump life? I'm guessing the second was more important. All modern pumps are protected by a ballast resistor or PWM, they do not want to be exposed to full running voltage for long periods of time, and their max output is not necessary for the function of the engine. It allows you to disable the vehicle by pulling the wires off it and slipping them under the harness. 98% of thieves will assume the vehicle is broken and not even look, since it will start and immediately die. Of the rest, well, most don't know what they're looking for.
Ryno Posted June 18, 2019 Author Posted June 18, 2019 Comanche Club for the win. You guys are awesome. I appreciate the responses. I`m guessing a PO removed it at some point... The fuel pump is pretty loud, but that doesn't really bother me. If it does actually extend the life of the pump I`d be game to but another one back on.
Ωhm Posted June 18, 2019 Posted June 18, 2019 You going to need to look in the harness loom near where the ballast is. Your looking for the Orange wire (fuel pump circuit) to determine if someone bypassed the ballast (two orange wires solder together) or is it a solid wire. Solid wire would mean more work would be required involving the O2 Heater Relay.
Pete M Posted June 18, 2019 Posted June 18, 2019 14 minutes ago, Ryno said: Comanche Club for the win. You guys are awesome. I appreciate the responses. I`m guessing a PO removed it at some point... The fuel pump is pretty loud, but that doesn't really bother me. If it does actually extend the life of the pump I`d be game to but another one back on. what year/engine is your truck? (and be sure to add those bits to your signature! )
Minuit Posted June 18, 2019 Posted June 18, 2019 Of course, if you have certain brands of fuel pump in your truck, it's gonna be loud as hell even with the resistor. I'm in camp "leave it" - they're so easy to bypass that it's no big deal if it fails. Anything that makes the vehicle quieter is a good thing in my eyes.
Ryno Posted June 18, 2019 Author Posted June 18, 2019 1 hour ago, Ωhm said: You going to need to look in the harness loom near where the ballast is. Your looking for the Orange wire (fuel pump circuit) to determine if someone bypassed the ballast (two orange wires solder together) or is it a solid wire. Solid wire would mean more work would be required involving the O2 Heater Relay. I`ll have to go back and look when I get a chance. I don`t remember two orange wires soldered together, I do remember seeing at least one plug with an orange wire.
Ryno Posted June 18, 2019 Author Posted June 18, 2019 1 hour ago, Pete M said: what year/engine is your truck? (and be sure to add those bits to your signature! ) Updated my signature
Eagle Posted June 18, 2019 Posted June 18, 2019 6 hours ago, eaglescout526 said: That’s the fuel ballast resistor. It’s there to quiet the amount of noise the fuel pump produces. Most everyone here bypasses it unless you want original looks to your truck With all due respect, I don't think that's an accurate statement. I haven't bypassed it on my '88 Cherokee or on either of my '88 Comanches, and I don't recall reading anyone saying they had bypassed it or eliminated it. We often suggest temporarily bypassing it as a diagnostic measure, but that's not the same as just forgetting that it's there.
BeaterComanche86 Posted June 18, 2019 Posted June 18, 2019 I’ll just add that the PO of my truck deleted this and I’m assuming spliced it together somewhere and I have no issues in the few months of owning the truck. I also have never noticed the fuel pump noise. From what I’ve read people delete these when the resister goes bad and don’t feel like spending money on a new one. AMC obviously had there reason putting it in but it seems without it your truck will be fine.
87MJTIM Posted June 18, 2019 Posted June 18, 2019 My '87 did not come with one. I believe Jeep added it with the '88 model year. So, BeaterComanche86, yours may not have come with one, either.
Jeep Driver Posted June 18, 2019 Posted June 18, 2019 9 hours ago, BeaterComanche86 said: I’ll just add that the PO of my truck deleted this and I’m assuming spliced it together somewhere and I have no issues in the few months of owning the truck. I also have never noticed the fuel pump noise. From what I’ve read people delete these when the resister goes bad and don’t feel like spending money on a new one. AMC obviously had there reason putting it in but it seems without it your truck will be fine. 2.5s never had one.
BeaterComanche86 Posted June 18, 2019 Posted June 18, 2019 3 hours ago, Jeep Driver said: 2.5s never had one. I'm learning the 2.5 didn’t have a lot that the 4.0 did. I was looking for my c101 for awhile till cruiser informed me it didn’t exist on the 2.5. Thanks for the info @Jeep Driver clearly I still don’t know S.
Jeep Driver Posted June 18, 2019 Posted June 18, 2019 45 minutes ago, BeaterComanche86 said: I'm learning the 2.5 didn’t have a lot that the 4.0 did. I was looking for my c101 for awhile till cruiser informed me it didn’t exist on the 2.5. Thanks for the info @Jeep Driver clearly I still don’t know S. The 2.5 does have the c-101 the 1986 Jeeps have no c-101
BeaterComanche86 Posted June 18, 2019 Posted June 18, 2019 3 hours ago, Jeep Driver said: The 2.5 does have the c-101 the 1986 Jeeps have no c-101 Exactly, I’ve since learned that since joining the site.
Ryno Posted July 11, 2019 Author Posted July 11, 2019 It seems the PO of my truck spliced one of the plugs to the resistor to the plug of the electric fan to have it run all the time... Maybe I`m looking at it wrong... I`ll have to take a picture when I get back. I don`t know why I didn`t take a picture last night when I was looking at it. I feel silly for not noticing before.
Minuit Posted July 11, 2019 Posted July 11, 2019 3 minutes ago, Ryno said: It seems the PO of my truck spliced one of the plugs to the resistor to the plug of the electric fan to have it run all the time
gogmorgo Posted July 11, 2019 Posted July 11, 2019 If that's just using the fuel pump wire to trigger the fan relay, that's not the worst place to put it, so long as it was done right. It would run whenever the key was on, but shut off during cranking. Of course that's still not a legit fix for whatever the problem with the fan was, but I can think of far worse ways to bodge that.
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