Originally Posted by mangomike
I took a look at the archives and have not found a clear answer to my question which is.
Do I have to disconnect the positive and negative lead from the engine to my house batteries in order to check to see if there is a charge coming from the engine alternate.
To put this another way if I put a voltmeter on to my house batteries before the engine is started,,, and they are charged,, I believe it should read 12 .7 or something like that. Now my question is,,, if I start the motor will the voltage jump because the engine/alternator is sending (if the system is working properly) juice to the house batteries.
Not that disconnecting the batteries is such a big deal,,, but it would be nice if I could simply put a voltmeter to the batteries and when the engine started I would be able to tell if the system is sending juice.
I hope I made my question clear???
Thanks for any help
You should be able to check the voltage at the coach batteries at any time, engine on or engine off and see what is going on, with nothing disconnected.
12.7v is fine with coach not running, and if it is a post 2003 Roadtrek 210, you would probably see 13.7-14.5v at the coach batteries with engine running.
If you don't see the voltage go up when the engine is on, there are a limited number of things to go wrong so should be relatively easy to find out what is going on.
* Check the voltage the isolator or separator that sends the power to the coach. It is under the hood, probably just to the driver side of center on the firewall. It should have in and out if a separator and one in and two out if it an isolator. You should see charging level voltages on all two or three big connections with the engine running.
* There will also be a single or double auto reset circuit breaker just after the isolator or separator and they are very common failure points. Check voltage in and out.
* There will be another single or double breaker just before the coach batteries on the other end of the cable. Same deal check voltage in and out.
* If you don't find the issue there, start checking for bad connections in all the wiring from wherever you see the voltage drop from charge voltage with the engine running.
Roadtrek changed from isolators to separators in the 2008-2009 range on 210s, so that would determine which you have.
You may want to look at the Roadtrek power simulator that is referenced many places on here, to see how it all works, as it is interactive.