2000 Contour/charging system prob.Need to solveASAP

[halbthere]

Last week I had a 2000 contour se v6 came in with complaints of 1)batt. drain 2)eratic gauges 3)smell of burnt plastic. I load tested the batt.found dead cell so replaced batt.started vehicle checked voltage 14 with no load,turned A/C & H/L's on voltage dropped to 11,and smoke from alt. so replaced alt.(I finally have seen that 800$ alt.R&R that u hear about on those insurance commercals.lol.)found that CV boot had flung grease into the alt shorting it (at least that was what we had ass-umed)As stated replaced alt. & axel.Started vehicle checked voltage again 14.5@Idle/2000rpm N/L,loaded system(A/C &H/L's)system dropped to13.5/14.5@Idle/2000 so we figure problem solved RIGHT/WRONG after running for 20min checked last time found 12.5/12.5@Idle/2000 no load 11.9/12.2@Idle/2000 loaded.Cust. needed vehicle back for weekend so was advised not to run the A/C or H/L's if poss.Vehicle back mon. with exact same elect prob. Need to solve this ASAP any ideas???

[Davescort97]

Welcome to AF!

Let me throw a few ideas at you. Most likely either the + battery cable, - battery cable or the hot wire (big wire) from the Alt. to the battery is broken or loose somewhere. Having the alternator wires on backwards will burn up an alternator, too, but I know you are a tech and wouldn't let this happen.

If the + cables on the battery or alternator are loose it will burn up a Ford Alternator. A bad + battery cable will cause voltage spikes in the system which will burn out the diodes. When the diodes are burned out current from the battery flows back through the alternator and drains the battery. The alternator light on the instrument cluster will sometimes light with the ignition off indicating the alternator is draining the battery.

The current is carried to ground through the battery, if the battery ground cable is insufficient the load goes through the alternator causing it to heat up and burn out. Add another ground wire from the - battery post to the frame of the car. In addition, it wouldn't hurt to run another ground wire to the alternator bracket.

Sometimes we make up our own battery cables and run these cables directly from the battery to the back of the alternator. This makes a simple, direct connection to the battery and eliminates the possibility of a wiring issue deep in the wiring harness. Again, connect to the larger gauge wire on the back of the alternator to the positive battery post and connect a ground wire from the alternator bracket to the battery. Rather than spending a lot of time looking for an open it is easier to just run a few new wires.

[jeremy06]

This sounds silly but sometimes a nearly seized pully on a/c(on mine in particular) or any pulley will do this as well. Will also cause starting issues.

[CnlK]

The replacement alternator could be bad. Couple of years ago it took me four replacment alternators for my windstar before I got a good one. First two quit charging after several miles. The third had bad diode and had a 4.5 amp draw when vehicle was off. As previously mentioned, check all wires and connections also.