Low Voltage on IP Gauge
 

Hi Guys,
First post in quite a while. Hope the experts can help me out on this one.

I was replacing my coolant elbows and the rear valve cover gasket. Anyway, I was in a hurry and did not disconnect the battery during this repair. Long story short. I saw a spark off of the alternator wiring harness (the 4 wire connector with a clilp) and also got one or two sparks off of the main charging wire (that goes to the fuse block).

Anyway, during the flush and fill procedure i notice that my voltage gauge (on the instrument panel) behaves normal during the start up. The gauge moves through a complete cycle then steadies out at just below 14V. The, about 55 seconds after starting, the reading drops to the lowest reading (8V) and never returns. Doesn't move even at higher rpms.

So, at first, I thought i did something to the alternator or the alternator died after the plastic coolant elbow blew out and spewed antifreeze upward into the alternator. But, I took the car to Autozone and the guy "load tested" it in the car. He said battery and alternator or fine. I also put a voltmeter on the alternator and it is putting out 14.7 volts.

So, I was wondering, is there some sort of relay that i might have "killed" during this whole process? I was wondering if the voltmeter (on the IP) starts out reading the battery voltage and then has some sort of relay to switch over at about 55 seconds after startup. I have driven the car maybe 10-20 miles since and (so far) the battery has not died.

What do you guys think?

Well, i figured this one out on my own.

It was a blown fuse.

Using my alldatadiy.com account, I looked up the wiring diagram for "Starting & Charging (Generator Control)". The diagram stated that ther was a "DIM Fuse 10A" in the "Fuse Block-Rear". I started going through any fuses that were 10A and related to the instrument panel. Anyway, evidently the voltmeter guage starts out sensing the battery voltage and then switches over to the alternator voltage after about 55 seconds. I had not noticed, but the autoleveling of the rear suspension was also not occurring. When i replaced the fuse, the voltmeter gauge is working and the autolevel sound is also now properly working.

Hope this helps anyone else that runs into this hiccup.