Message: Check charging system on 96 Diamond edition


So I put a meter on the battery and at 1200 rpm the Fluke meter reads 18.5 vdc. Can hear a whirring sound under the hood and the airshock pump revs up with engine RPM.

Any ideas?



El Presidente
Staff member
The "Check Charging System" warning message is displayed on the message center when the battery voltage is too low (not charging) or too high (overcharging). 18.5 vdc is overcharging, so there is definitely a voltage regulator problem. Time to have the alternator rebuilt or replaced.


Lincoln Evangelist
Staff member
Paid Member
Yup. These alternators are internally regulated.

I've kept one of my old ones on-hand so I could rebuild it with new bearings and regulator, but I've been sitting on it for years now, and still haven't done it. :)