alternator hot

[beenthere]

when parked and hooked to shore power my alternator fan that the pully is on is very warm.....so I shut off the inv-conv and the in use botton and the switch on the conv panel and its still stays very warm ...this is probably why my chassis starting batteries go dead after a day or two....is there a test I can do or has anybody experienced this? my son said the diodes for current going back and forth are bad.....jeff

[Skip426]

There are many places to have an alternator bench tested if you remove it, or you can drive it to a facility for testing on the rig.
You say the chassis batteries go dead in a few days; is that a few days parked & plugged into shore power ? or a few days of driving ?
Have the batteries ever been load tested ? Bad batteries can lead to all sorts of issues with both the chassis charging circuits and the convertor charger.
Is this a new problem on a coach you've had for a while ? Or a new to you coach?

[camperkids]

Jeff, your son is correct the diodes are bad and it will cause your batteries to go dead. It's back feeding that's why it's hot to touch. Take and have it bench tested . Jim

[beenthere]

thanks Jim ...My son did go to elel engineer school for a yr but he made so much money writhing Linux clusters that he said it was waste of money....and that would explain why it happens pugged in or not...looks easy enough to take off...jeff

[beenthere]

got my alternator back today...cost $160for rewind and regulator and diodes bearings,,brushes ect...and midway diesel always does better than new performance...no cheap electronics...now to put it in and hook batteries{which after a charge are holding 12.8} ,,,jeff