Could someone with a wiring diagram for a '02 Blazer tell me where the instrument panel voltage gauge measures the voltage at?
Just today I noticed that the voltage gauge is not showing 13.6 - 13.8 like it always has. I checked across the battery terminals with engine running, had 13.6. Across battery terminals with engine off 12.6, then an hour later 12.5. So I think the alternator and battery are both good.

Want to put my voltmeter at the same location as the battery gauge and compare.

Thanks

 

12v comes into the IPC on three fused wires, not sure which one is the take off for the volt gauge. They are Cruise fuse 10a, Gauges fuse 10a, RDO batt fuse 15a.


George

 

Thanks GeorgeLG; just a simple matter of pulling each fuse and watching when the volt meter goes to zero.

Also, I did another test drive and noticed that the volts would drop after a few miles which is after everything got all warmed-up. Measured voltage across battery terminals again; first with high beams and 4 way flashers on....was like 12.32V. Turned off the headlamps and voltage reading went up just a bit to 12.5V. Turned off 4 way flashers and got 12.6V.
I think the regulator in the alternator is failing when it gets hot. Looks like time to get the alternator rebuilt (again); been eight years and not sure if the regulator was replaced at that time or not.

Thanks again for the info.

 

my pleasure. George

 

Well....volts gauge is reading correctly. Pulling the Gauges fuse does kill the gauge; the Cruise or RDO Batt fuses have no effect on the Volts gauge.

The issue of getting a lower than normal voltage reading seems to occur after using the turn signals. I can see the Volts gauge needle fluctuate with each turn signal flash, but after turning the signal off, the Volts gauge does not return to the normal position, always a bit lower and it takes 15-20 seconds for the needle to get there.
Turning on the headlights or the 4-way flashers have no effect on the Volts gauge needle position. So apparently the issue is not current related, but something within the multi-function lever as the windshield wipers have developed an odd operation in that the wipers will not go to Park and just stop at random positions.

I have not looked yet to see if the multi-function assembly is even available anymore.....doubt it is.
Looking like I get to spend some quality time under the steering column checking into this. Good thing its only 105°F or so this week and my back has not been aching for a while now....so this should take care of that in a short time.

Later,

 

Thanks for the feedback on the fuse.

George

 

With my DMM across the battery terminals measuring dc volts, I watched the alternator output voltage drop from 14.10Vdc at start to about 13.65Vdc after 20 minutes of engine running with various loads. I am convinced that the alternator is the issue and will be getting it rebuilt unless I can find a regulator and replace it myself. I do not think there is anything wrong with the multi-function switch (yeah!!!).

 

@GeorgeLG Have a favor to ask; could you scan the turn signal schematic for me? Still chasing this electrical issue. Keep changing my mind on what the problem is. Do not want to replace parts without troubleshooting.

The low voltage indication only happens when the turn signals are used. Putting the 4-way / hazard flashers on does not change the voltage meter reading, neither does headlights low or high. Something seems to be wrong in the turn signal path. I pulled the flasher unit out, then moved to left or right turn with no impact to voltage meter reading. So, again, doubt it is the multi-function lever. Want to see the schematic for the turn signals, see what connections are different between turn signals and hazard flasher units.

 

Will do, I’ll take care of it when I get home tonight

George

 

Here you go

George