voltage increase

[GMS]

i just got my 02 tb and i noticed with the engine running [driving or idling]if i turn on the radio or ac/heat my voltage goes up.
if iam just idling and turn the ac on it starts to idling high ,turn it off it goes back to normal,





PS JUST BECAME A MEMBER SO GLAD I DID THANKS
TO ALL U GUYS THAT HELP CLUELESS PEOPLE LIKE ME
GMS

 

[The_Roadie]

Welcome!

Just got it like how long ago? What's the mileage? Any idea of the maintenance history? Did a mechanic do a pre-purchase inspection? Can you provide numbers to help us help you more precisely? What's the RPM at idle? What does it increase to when you put on the AC? What's the voltage when you think it's low and when it's high?

If you leave the AC on, does the idle go up and down every 5-20 seconds, and ever feel like it's going to stall out?

What happens to the voltage if you run a window or two up and down? That requires more power from the electrical system than turning on the radio.

 

[GMS]

just got it 3 weeks ago ,dont know maintenance history,i did tuneup ,sparks and oil nothing major,167000,had someone look it over not in a shop,gauge at idle about 14 with nothing on ,power window also affects idle[turning the steering wheel all the way L or R] does not go away and feels like it wants to die until its all off

 

[The_Roadie]

1400 RPM is a very very high idle. A vacuum leak or disconnected fuel pressure regulator might cause 900, but not 1400.

Did you use Delco 41-103 plugs? Only one that had uniformly good results with the I6 engine.

You probably need a good throttle body cleaning.
http://gmtnation.com/f25/how-clean-4-2-inline-6-throttle-body-221/

Check the voltage with a meter, not the dash gauge, and report back the precise readings.

Also if you have 4WD< make SURE the transfer case fluid gets changed ASAP. It needs doing every 50K and many owners are clueless or cheap and ignore it. To your detriment if you adopt such an abused puppy.

 

[CaptainXL]

i just got my 02 tb and i noticed with the engine running [driving or idling]if i turn on the radio or ac/heat my voltage goes up.

Agree with Roadie. How much does it go up by?

 

[bobdec]

OP said "gauge at idle about 14 with nothing on" I assumed that was voltage not RPM.. which would be close to normal. If truly RPM then that's a problem...

 

[The_Roadie]

Bob, you might be right. We volunteers ask detailed questions around here, and if we get detailed answers to them all, there's a good chance at an accurate diagnosis. Otherwise it's just flailing and guessing.