Charging Drop When A/c Is On

[Hillcountrymac]

Hey guys, my alternator goes from about 14.5 to about 11 intermittently when the A/C is on.I haven't put a meter on it to get the exact numbers but you get the picture.I can't tell if it is when the compressor kicks on,but probably. Ya'll think it is just the main ground on the block or is there another likely culprit? Thanks for the help,I plan on keeping this truck a long time and I'm learning a lot reading this forum everyday......Thanks again

[Eagle]

More likely your alternator just can't keep up with the extra load of the a/c. However, you need to check it at the battery with a multi-meter, not rely on the factory gauge in the dashboard.

[gogmorgo]

The electrical components of the a/c system are the blower motor, the compressor clutch, and the auxiliary rad fan. Because of higher engine load, the rad fan would kick on/off to take care of extra heat. Combined that's a fair load on the alternator, but I think you'd be noticing the issue in other situations, such as turning on the headlights, if it really were an issue with the charging system.

You can get your charging system tested at most parts stores, probably for free.

[cruiser54]

Start with verifying the actual voltage. 

 

Doing the ground refreshing is ALWAYS a good idea.

 

See Post 1 in the link below.

[Hillcountrymac]

Thanks everyone for the feedback