boeingxtreme

My cherokee has always been an electrical nightmare, really starting to get everything cleared up, or so I believe. Heres the next issue, it wont charge up to 14 but it only gets down to the red, 9?, when it has a good load on it, such as the rear wiper, front wipers, blower and then the turn signal on makes it bounce a little, I had autozone do their computer thing on the battery that test the alternator and they said it was good, but it just isnt right. My buddies 91 charges over 14. Is there some kind of regulator that allows the battery to take more in? Its a brand new 880 CC Interstate Battery. I also read that something with motor temp has a switch, PO took the thermostat out so that in the winter, when plowing, the jeep wouldnt get hot, could this be related?

Thanks Dan

The_ocho

Get an aftermarket gauge. factory gauges usually hook into a circuit far away from the battery or alternator after all the other components sucked off power or develop a bad ground and on top of that they aren't very accurate. spend $20 and get an aftermarket same for your oil pressure

cruiser54

Here's where I would start on any Renix Jeep. Add the cables as noted in the write-up also.

Renix Ground Refreshing
The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.
The components grounding at the dipstick tube stud are:
Distributor Sync Sensor, TCU main ground, TCU "Shift Point Logic", Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.
The factory was aware of the issues with this ground point and addressed it by suggesting the following:
Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.
Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.
While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.
Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end.
First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3’4" socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.
A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18" long with a 3/8" lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.
A further improvement to the grounding system can be made using a #4 cable, about 10" long with 3/8" terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.
　
　
If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price.
　
Revised 11-28-2011

88jee

Don't really think not having the thermostat in and the electrical issue are related but I don't really think it is ever that wise to run a street car without a t-stat. Especially during the winter, I would think you would want a thermostat to get the car to operating temp. Whatever works I guess...

boeingxtreme

Its been on my list to get one in there, I know they arent bad to do, have done one on a 97 TJ 4.0,

boeingxtreme

Put a new sending unit on oil pressure and the voltage gauge seems to be right on when using a gauge on the battery as well.

boeingxtreme

Ive cleaned the ground that was spoken above that is just forward of the dipstick, have not messed with/ knew that there were other grounds, Im almost certain that one by the dipstick is covered in oil. Is there any Voltage regulator or anything? someone told me that there could be.

cruiser54

Voltage regulator is inside the alternator.

cruiser54

Get a thermostat from the dealer. 83501426.

boeingxtreme

Will do, Do you think it'd be worth trying to replace alternator? Or?

DFlintstone

If you are getten 14ish at the battery, I doubt the alternator is your issue. There is a thing on the instrument panel round in my signature.

boeingxtreme

I meant when I put a meter on the battery when running, it was right on with what the gauge said at around 11.5-12.

cruiser54

Do the ground refreshing including adding the extra cables first.

boeingxtreme

Alright, funny cause I have a set of cables that I was gonna replace when I bought the jeep. They're a larger gauge wire.

DFlintstone

Yea^. I cleaned and added grounds myself. I guess if you have a big blue wire going to the big lug on your starter relay. That's the fused link where the alternator power comes into the system. I've never had trouble there, but if that were getting hot and or not connection well, of course you would end up with low power. Here's some diagrams...for what it's worth! > http://www.scribd.com/doc/11033020/Jeep-Cherokee-1989

You are sure your belt is good and tight? Voltage is the first place it shows when mine is loose.