The other day on my way home from work my battery light came on and my voltage gauge was running a bit below normal range. I figured no big deal i'll pick up an alternator the next day. Well the next morning I barely made it to work as voltage dropped pretty rapidly.


That afternoon installed the new Alternator but had to jump start her as the battery was dead. New problem, battery would not seem to hold charge. So the next day I picked up a new battery and new terminals. Installed new battery and terminals and she fired up no problem, and no issues on the drive home.


However this morning on my way to work my battery light kept flickering on and off, but my gauge was running in the normal range. So after work I popped the hood and re checked all of my connections. Checked voltage at battery with DMM and with car running checked voltage coming from alternator. Let her sit running in the parking lot for about 15 min with lights and AC on and gauge stayed in normal range.


About halfway home gauge started dropping rapidly again, though the battery light never came on. When I got home I popped the hood and I wiggled the stud for the positive lead on the alternator, and I noticed if I applied a certain amount of pressure it would kick in and my gauge would go back to read normal, but if I slightly touched the stud again gauge would start to drop.


Am I correct in assuming my new alternator is faulty. Or could the problem be in the cable it's self. All of the insulation on the cable seems to be good and the end of the lead itself is clean and free of any corrosion.


Any tips on other things to check would be very much appreciated.

 

Do a little more testing. For now forget the gauge on the dash & use your DMM. With engine running, voltage across the battery should be ~14.0v. Test voltage at B+ terminal at back of Alt -> 1 lead to ground (preferably bat neg) and the other lead to B+ terminal - should be same as battery reading (~14.0). The B+ terminal on the back of the Alt goes to the power distribution terminal on Battery Junction Box. Do a voltage drop test on this wire - 1 lead of DMM to Alt B+ terminal & the other lead on the power distribution terminal. A good wire will read less than .5v (or 500mv), the higher the reading, the more resistance in the wire. You can try to wiggle this wire around while performing this test to see if voltage goes over .5v (it shouldn't). BTW, voltage drop test can be done with engine running or engine off. Voltage during voltage drop or voltage reading should not vary while moving the wire at the B+ terminal on Alt.