Coach Batteries Charging Solenoid Issue

[rmjhhunter]

My 2000 Rialta has a problem with the charging/auxilary-start solenoid. When I hook up to 120VAC I read 13.5 VDC at the coach batteries. This is correct. However, when I have disconnected from 120 VAC and start the engine, the coach batteries are only registering 12.5 VDC. I expected that the engine would be charging the coach batteries but, if this was happening, the batteries should register 13.5VDC. I spoke with Winnebago Technical Services and they assure me that the charging/auxilary-start solenoid has dual purpose - to allow the coach batteries to be used to start the engine but also to allow the engine to charge the coach batteries. On a recent trip the refrigerator was on "battery" and when we completed that day's trip our coach batteries were dead. A new solenoid purchased from Winnebago did not solve this problem even though they assured me it would solve my problem. Has anyone experienced this? Anyone have a solution?

 

[dhpenfield]

I had a similar problem in my 2005 QD. I bought the new solenoid and it seemed to make things better for a while. But soon the coach batteries wouldn't stay charged. If I accidently left the coach batteries on the coach batteries and the engine battery would be dead. The coach batteries were no good. Not sure if the bad relay killed the batteries or just old age. It sort of sounds like what you're going through, so that may be something to consider.


Something interesting is that the coach battery is connected to the engine battery by the solenoid, so the voltage of the engine battery and the coach battery should be that same when the engine is running. A few things to check since you replaced the solenoid. The AUX Start switch may be giving you some trouble. When you aren't pressing, it sends voltage to the solenoid when the ignition is on. If that switch isn't working, or if the connector is loose, there is your problem.


Hope this is helpful.

 

[ehberkun]

I had a similar problem in my 2005 QD. I bought the new solenoid and it seemed to make things better for a while. But soon the coach batteries wouldn't stay charged. If I accidently left the coach batteries on the coach batteries and the engine battery would be dead. The coach batteries were no good. Not sure if the bad relay killed the batteries or just old age. It sort of sounds like what you're going through, so that may be something to consider.
Something interesting is that the coach battery is connected to the engine battery by the solenoid, so the voltage of the engine battery and the coach battery should be that same when the engine is running. A few things to check since you replaced the solenoid. The AUX Start switch may be giving you some trouble. When you aren't pressing, it sends voltage to the solenoid when the ignition is on. If that switch isn't working, or if the connector is loose, there is your problem.
Hope this is helpful.

 

[sfortney]

I also have the problem of the coach batteries not charging with the engine running but charging on the converter. The batteries are 4 years old. Will that contribute to the problem or is it the selenoid. Is there a way to test the selenoid other than measuring the voltage with the engine running?



Sid Fortney North Carolina

 

[Bblask75]

I have the same problem: running the refrigerator off coach batteries while driving, after 3-4 hours on the road the low voltage alarm goes off. Plugging in to a campground 30 amp 110V charges the coach batteries nicely.


So, the engine alternator is not charging the coach batteries: either the charging/auxilary-start solenoid is bad - and I plan to replace this original 2002 part in any event, the charging circuit from engine to coach batteries is fauty - and I'm asking VW service to test this, or something in the circuitry of the refrigerator is misbehaving and pulling more amps than the alternator can keep up with. I'll look at the Aux switch next.


NB: the batteries are less than a year old, marine deep-cycle heavies.



Bill Blask, South Carolina