Mazda 626 RPM Drops from 7500 to 5000 RPM when heat is turned on

[steelhead11]

Mazda 626 RPM Drops from 750 to 500 RPM when heat is turned on

Hi,
Thanks for having me!
I have a 2002 626 4 cylinder and I'm having an issue.
With the car running, I'm reading 14.5 volts across the battery with no load and no issues. When I turn on the heater on, every 5 seconds the car dips to 500 RPM for a split second and jumps back to 750 RPM while the voltage drops to 13.5 and back to 14.5.
I had the charging system checked and it appears to be fine.
Any information would be appreciated.
Thank you

 

[blackedoutFC3S]

Do you mean 500 to 750 RPM's? If it's in the 5000s you have a much bigger problem haha.

It should just be the load on the system. Doesn't seem like much of a problem when it goes back to normal.

Kinda like when you put down your power windows and the lights dim, it's just a load on the electrical system.

 

[steelhead11]

Nice catch. I understand the load, I think now the decrease in RPM has become more pronounced.