90 century stalls when cooling fan comes on

[sharkie1962]

Hi all I'm a newbie

Any help with this one would be appreciated. Vehicle runs normally on cold start up and idles ok until cooling fan comes on. rpm drops and engine stalls. will restart ok but stalls if fan is still on on its cooling cycle. no check engine light on but has code for "lean exhaust detected" have removed idle control valve and clean it (was not very dirty) cleaned throttle body. checked for vacuum leaks, seems ok. What do you think I should do next?

Thanks sharkie1962

[richtazz]

check system voltage. It sounds like you might have a marginal alternator, and when the fan kicks in, it draws the voltage down and causes the car to stall.

[sharkie1962]

Hi Richtazz
Thanks for the quick response. I thought that could be the problem so I ran the car with another car jumper cabled to it. It still stalls when fan comes on. The battery seems ok as I can leave the lights on for 20 minutes and it will still crank over strong. puzzled by this one.