Community Forums

KTMONE · 09-05-2010, 08:12 AM

Help, looking for any suggestions on troubleshooting a DC charging problem. I have a 2005 Phaeton 38 the problem is the batteries do not charge while the engine is running. Charges ok on shore power and Generator but not while driving. I have determined this as the DC voltage at the battery remains the same when engine is off or running. The DC voltage increases at the batteries when on AC or Gen power. On a previous coach I had a similar problem and replaced a solenoid but that was a much simpler coach. Near the batteries there is a bank of heavy duty solenoids but can’t tell which one would manage the charging circuit. Suggestions?
Thanks

OneRVer · 09-06-2010, 03:57 PM

Well, when your generator is running or you are on shore-power your batteries are being charged from your converter. While your engine is running your batteries are being charged from your alternator. I would first make sure your alternator is working properly. Is it possible to trace the heavy duty wire from the alternator to the battery compartment? This should take you to the right solenoid. Check all connections for corrosion or loose terminals. Good luck.

wa8yxm · 09-06-2010, 06:44 PM

On a motor home there is a device called an Isolator, this may be a long box with fins and 3 big wires on it (optionally a 4th smaller wire) or it may be something that looks for all the world like a Ford starter solenoid (They are NOT interchangable)

I have a friend with a diode isolator that has an open diode.. Same symptoms you have

If you have a solenoid isolator it might be the solenoid or it might be the control board.

Personally.. I prefer the solenoid type.. And bi-directional as well.

(A bi directional solenoid will charge the chassis battery off the house converter, as well as the house battery off the engine alternator)

doublej1808 · 10-16-2010, 08:01 PM

On my coach, 2010 qrp, there is a large fuse (100 amp) in the engine compartment that was blown. you may check there.

Keith & Sharon · 10-16-2010, 10:28 PM

If it is only the house batteries that are not charging, check the charge solenoid in the electrical bay as these some times stick. you can go to the A Part of the TiffinRVNetwork • Index page web site and ask as there are many knowledgeable people there that have your model coach.