Charging System Help!!

[DBSINWI]

Last night, we had the classic symptoms of a bad alternator: A gradual loss of power, dimming headlights, and eventually nothing until the G Wag quit. I attached a jumper pack and drove it home with that. Today, I replaced the alternator (even though it tested good at the local NAPA) and the battery. But I'm still having the same trouble. The dash gauge reads about 10 volts or so (in the red) and now my door locks and power seats don't work. There is also a long, thin white connector hanging down under the dash. It has about 14 pins with about 12 wires in it and comes from the driver's side of the dash then goes to the middle of the dash and doesn't seem to have a mate to plug into. Obviously, something else is drawing power. Where should I look?

[carrotman]

Check the fuses first to see if any are blown. If not, it could be a short in something that is not fused. Perhaps the starter?

[grand_wag_85]

My wag has the same problem sometimes. Clean your grounds. What year is your wag?

[DBSINWI]

Mine's an 86 with the 360. What grounds specifically should I check? Where are they? This is the first Jeep I've ever owned, so I know very little about them. Is there any connection between my seats and locks not working when they did before?

[Tripwire]

Had a very similar problem last month...dead battery - no charging and the locks did not work. Turned out to be one of the 4 fusable links. these are green wires with tiny white lettering on them that say "fusable link". they are located on one side of terminal posts of the starter relay ( the side that the battery cable hooks up to) some are a Y type with to leads connecting to 1 ring terminal. The one probably bad is the one that goes to the alternator and locks. My Rig has 4 links, one for the alternator, one for the seats and locks, ignition switch, and fuse box. IMHO sometimes they occasionaly just go bad - but usually there is a good reason why they blow out. be sure to check all the wiring closely and use a multimeter to check for shorts to ground.

[DBSINWI]

The fusible links seem to be OK. They are not melted or separated. Could they be bad inside the black "fuse" area and still look ok? A bit of background: a couple of days ago, the rig worked just fine until the headlights were left on for most of the day. This, of course, caused the battery to die. Since the jump start to get it running, it's been doing this. I'd still like to know what that white connector is under my dash.

[oldjeepr]

well the plug sounds like a under dash stereo plug harness that was wired into the speakers and wires and the previous owner took the unit but left the wires, that happens,

[mdill]

Fusable links, can be bad without showing on the
outside. A fusable link is just reular wire, but the insolation
is such that it does not melt though when the wire
gets hot and melts, this is done to prevent the
fuse from melting into the other wires and distroying
the harness.

On your alt there are three terminals, the big bat
terminal, that should have ~0 resistance back to the
battery + terminal, the two small ones on the
clip connector, the samll red (Sence line should
have ~0 resistance back to bat + teminal) The yellow
whaich should be switched + (Ignition on) should
have 15-50 ohms back to + bat terminal with igntion on)

If those check out and there is no charge, you can
try and the regualtor bypass in the alt by putting
small metal rod in the D shaped hole in the back
of the alt and shorting the little tab to ground,
this turns the field to full on, but becafe full
as pushing in the rod to far you could damage your
self as well as the alt, and getting to the hole
on a waggoneer with air while the engine is running
would not be a fun task, that could be easily done
safely. (I have used the bypass on the older SI10
alts. but since I don't know what you have on yours, you
are on on your own for figuring if you have this on your alt.)

Good luck.

Mike D.

[Tripwire]

Mike is right...Ya gotta ohm out the fusable links you wont see any "blown indication" from the outside - NAPA sells link wire its about $5.00 for 10 ft - just take a piece with you so you get the correct gauge. The black rubber things are just crimp connectors......

also a unrelated charging problem i had on the other waggie was because the replacement units availabel from Shucks was only about 1/2 the amps of factory spec one - combine that with a too small battery and starting woes were enevitable. I stuck in a 85 amp unit and the correct capacity battery and now my problems went away (they were due to the wife only driving about 5 miles round trip to work every day)

If you dont have any luck I have the factory wiring diagrams from Jeep ( 86 wagoneer 258 + 360 versions) and they will help alot...I could fax them to you....If I had a Scanner I would try to post them on the web site

[Tripwire]

as for the drawing power problem - get your meter set it to amps - you may have to move the red lead goes where it goes in the meter. disconnect all the wires off the starter relay where the battery connects - now, connect the meters positive lead to the battery terminal, and the negative lead to one of the many wires you took off the terminal. read how many amps / miliamps each leg of the system is drawing....you should only see a few miliampers on one or two of the wires...one will be for the clock/radio circuit which on my rig is about 15 milliamps and the oyher will be from the red wire that runs abck to the plastic connector on the SIDE of the alternator ( the voltage regulator circuit. mine was about 20 milliamps.

Your chiltons wiring diagram should help out some - also I seperated all my fusable link circuits by eliminating the "T" in each leg, so now each leg has its own link instead of shareing a common ring terminal - that helps isolate where the problems lie. if you find curent draw other than what i mentioned, be sure the key is off and start pulling fuses one at atime till the meter shows no current drain. ( dont forget the Dome lights when you open the door to pull fuses)

[DBSINWI]

it did turn out to be the fusible links! It looks like I blew two of them when I jump started the thing the other day. The seats and locks are working now! Next: replace the fuel sender! I'm glad I don't have to take the tank down to get to it!