Voltage drop AC problems

[Billy Southerland]

I’m experiencing some issues with my truck. It’s been going on for a while but now that the heat of summer is back upon us I have to figure this one out. My AC blows cold when I’m driving very cold but when I stop and idle it begins to get warm. I’ve noticed that my battery gauge also drops at the same time. Any advice would be appreciated. I don’t know if the two are related or if I have two separate problems that just happen at the same time.

 

[Uncle Gump]

What engine?

I ask because some of the 4 cyl engines used an electric fan when the a/c is operational.

Typically when it cools well going down the road and doesn't sitting still... you aren't shedding heat in the condenser due to lack of air flow. So electric fan problems... mechanical clutch fan problems or even a semi blocked condenser.

Could the two issues be reated... yes. But I'd start with one.

 

[Billy Southerland]

I have the 4.0 v6. I just tested with my multi meter again and waited for the problem to come back. I’m reading a good 13.5 or so but I did notice some lower fluctuations at times. I’m going to take it up to auto zone and see if they can give me a more accurate reading. I’ve considered the fan being an issue would that put a strain on my battery as well?

 

[SenorNoob]

Depending on the failure, yes it's possible. Though usually they just stop and or blow fuses.

 

[Uncle Gump]

I have the 4.0 v6. I just tested with my multi meter again and waited for the problem to come back. I’m reading a good 13.5 or so but I did notice some lower fluctuations at times. I’m going to take it up to auto zone and see if they can give me a more accurate reading. I’ve considered the fan being an issue would that put a strain on my battery as well?

The 4.0L doesn't have an electric fan. So no... a mechanical fan won't effect alternator. Unless it's locked up... where in theory that could effect idle speed. But if it's locked... it's pulling max air through the radiator at idle. Which doesn't line up well with low airflow at idle.