Biohazed

OK my Cherokee doesn't want to charge .... I get approx a 1-2 volt drop with the headlights... however with nothing on it does slowly charge .... I changed the Alt, Battery wires and Battery and still have this problem .... SO at this point the only things I can think it can be is either the Trigger wire or the Charge wire .... I need to get my voltmeter from work to verify this ... However my questions are:

1- Is there a Fuse and or relay for the charging system?
2- on a '90 is there a external Voltage regulator?
3- on the 2 wires that plug into the alternator, which wire is the 12v trigger?

kjc

Sorry, I don't have any answers.. this pic is from a dvd manual i have, supposedly for a '93 GC but I'm not sure. I know my '93 has NO external regulator.

cruiser54

Voltage regulator is internal.
No fuse, but the charge wire has a fusible link in it.
Yellow is trigger wire.

Check charge wire at alternator for battery voltage. Check yellow wire at plug for voltage with key ON.

Biohazed

OK got into it a little deeper and what I have as of right now is 14.7 to the battery ... so I know its definatly charging .... Now on the Starter Relay (metal box right near the battery were the Charge wire and the charge wire to the battery connect to and seems to be the main voltage control area) I get 14.7 at the terminal .. and the other connectors I'm getting 11.8-11.5v from the blade connectors .... so I'm thinking that's gonna get changed tomorrow ...

cruiser54

Have you checked the yellow trigger wire at the alternator plug for power with the ignition on?

Biohazed

yes its good Ilike isaid I do have great charge at the battery .... I''m actually thinking about running a few more grounds and see if it makes any difference.

cruiser54

Here ya go. Proven and effective with no guesswork:

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

Biohazed

got it straightened out, ran some 8ga wire from the battery to one hinge ran another length to the other hinge the ran a piece from the hinge to the firewall ground bolt now its perfect.

thanks for the help!

cruiser54

Don't ignore the refreshing of the terminals on the dipstick tube stud. They'll haunt you at some point.

Jeffvador

what are the "hinges" your talking about?