Ballast resistor

[sdokter]

I have a 1988 jeep cherokee with a a 4.0. The question is why would the ballast resistor get hot and stall the engine. I replaced the resistor but it does the same thing. It will run for a couple minutes then it stalls. I let it cool down then it starts right back up. Any Ideas.

[Pete M]

When it stalls, does connecting the 2 wires together (bypassing the resistor) get it to run? The resistor is only there to reduce the voltage to the pump and lessen the noise so bypassing it won't hurt anything.

[sdokter]

No bypassing it does nothing.

[Pete M]

Then it's not the ballast resistor.

 

When it cuts out, check it for spark and for fuel. That should help narrow it down. :thumbsup:

[mjeff87]

sounds like a bad ignition module to me.

 

Jeff

[Wildman]

Or your fuel pump is getting ready to retire......

 

.......if you let it "cool" off, and then you can re-start and run.......the pump is getting "hot" and ceasing up, shutting off the fuel flow.

 

If you can, do a fuel pressure check first, and see if the pressure drops off before the engine quits.

[sdokter]

The fuel pump is new I allready replaced it. But today I bypassed the resistor and it started right up, if I hook it back up it won't even start the resistor just gets real hot. What would cause that?

[Wildman]

You said in your 3rd post-

 

No bypassing it does nothing.

 

:hmm:

 

 

The ballast resistor will be "warm" to the touch, kind of the reason it's make out of ceramic material, reduce voltage flow = heat.

 

If it gets really Hot, then it's time to replace it. If the truck started and ran after you by-passed it, again, then it's shot.

[sdokter]

I have three extra ballast resistors it does the same thing with every one of them, it doesnt get warm it gets extremely hot. The weird thing is the fuel pump won't come on if the ballast resistor is hooked up, but if bypassed it comes on but it is really noisy. I was switching resistors with my other jeeps and they all work fine. I also changed all my ground wires thinking it was a bad ground causing the resistor to get hot.

[mholleywould]

Just a thought, but have you checked the filter. My thinking is that at high presure { DIRTY FILTER } could cause the pump to stall { if it has a resistor on it } and after it sets a little fuel will seep through thus lowering the presure allowing the pump to kick on with less resistance. and that little fuel that gets by will allow the truck to run for a little bit. Just a thought.Trying to cover the basics that are so often over thought.

[cmelo]

My ballast resistor gets so hot it smokes. This is with a brand new one. I have yet to swap out the fuel filter and I will try that first.

[HOrnbrod]

Don't use a "universal" ballast resistor like you buy at Autismzone and the other chains. Get one from the dealer for about the same price that will be the correct ohms value.