Missing ballast resistor, VERY loud fuel pump

I noticed that in my '87 XJ that I have no Ballast Resistor. My fuel pump is loud, and I have read that the Ballast Resistor was there to quiet it down. I can hear my fuel pump if I try to listen for it, but the engine noise drowns out most of it. BUT after driving for a while, especially if I am on the trails with no road noise the pump will gradually get louder and louder, until it is a real loud hum almost like a squeel but not a reeeeeeee squeel. Its more like a high pitched humm. When I first start and run I just hear the normal deep hum that goes like Murrrrrrrrrrrr. Is it my fuel pump going out.

Here is a pic of my fender with missing balast resistor

87 didn't come with the ballast resistor, there are also some minor wiring differences in the later model Renix's, the ballast resistor is bypassed during start.

ok, thanks. What about the Loud fuel pump. If it keeps getting louder and louder, does that mean that the pump is about to go out.

You can add the ballast resistor yourself - I'd have to see if I have the TSB on it anywhere.

It was added in late 1987 as a "voluntary recall" for NVH, and I think it was actually implemented as standard in mid-1988 (my 1987 doesn't have one, and it was very clearly added in my 1988.)

The value of the resistor should be relatively small - like an ohm or so. Nearly every ballast resistor I've seen in any application is 10 ohms or less, with preferences for values under 5 ohms.

I don't know about the 87, but on my 89 there is a TSB for retrofitting something to quiet down the pump. I've always just said screw it. It's loud, but so is my exhaust, and my intake, and my hatch, and the wind noise, and the tires....it matches the rest of the Jeep. Plus, how else would I know when my stereo is loud enough?

Supposedly, a louder than normal fuel pump is an indication of a gloomy future for the pump. I'd be especially concerned with its longevity if it gets significantly louder after the initial turn-on, like yours is doing. If it were me, I'd go over the complete fuel system to insure all hoses are good (not collapsing for some reason), and that the charcoal canister is not saturated, since it's the fuel tank vent. It could be, as the fuel heats up, and the tank needs to vent, it can't, putting a suction load on the pump; you could try removing your gas cap the next time you hear the change in pump noise.

Where is the charcoal canister at. I don't think I have a problem with venting (my vent seals are bad and leak when on hills), but I will check it just to be safe.

On an '88, with a 4.0, the canister is located on the passenger side of the engine. It has a tube running to the fuel tank, and a tube running to the air hose connected to the throttle body. The tank vents into the canister, and the engine sucks it out.