starting rig with generator running

[cosmic]

last year i blew my alternator when I started the rig while still hooked to shore power.

My question is what will happen if the genny is running and i start the rig. will this also blow the alternator? as it would be just like being hooked to shore power. no? i??

[ibdilbert01]

Yikes    I think first we need to find out why plugging into shore power while running the RV blew the alternator in the first place.    I've started mine plenty of times while plugged into shore power, no issues yet.   I also run my generator while driving too.

[moonlitcoyote]

I have also started mine many times while plugged into shore power, it never crossed my mind not to. It will be interesting to find out what happened to yours and if there is something we should all be keeping an eye on.

[Oz]

Same here as the last 2 replies on starting the RV while plugged into shore power but, let's get the original question: should the RV be able to be started while the generator is running (?) answered and then take a look at the other if it's still a problem. 

One thing about the shorepower problem.  You said that happened last year... have you started it on shore power since?  And, if so, it didn't happen again?

[cosmic]

The last alternator cost to much to try it again.

[JDxeper]

My understanding is that if the MOM switch is in the dual position, and either the gen or shore power are feeding the converter it will damage the alternater when the engine is running.   A battery isolater is supposed to not allow this to take place.   Just what I can remember from some where!  Could be a bad battery isolator. i??

[cosmic]

sounds like that could be the possibility. thanks JDxeper

[JDxeper]

OK just found the reference in my 78 owners manual, page 22, under dual battery switch.

WARNING  

Do not turn on the optional 110 V generator with both batteries connected while driving.  This can cause damage to the automotive alternator.

I assume the same would be true if you started the engine when connected to shore power. The system can not tell the difference, at least on mine 78, no auto switch  just plug into the outlet for the genset or shore power.

[cosmic]

BINGO
Thank you for clarifying this for us. This more then likely is what happened to me on shore power. And could do the same thing with the genny.
I don't want tell you guys what this mistake cost.  So listen up.

thanks again JDxeper

[cosmic]

As a fallow up to what happened to me. I do run my generator while driving down the road, and have not had any problems with the alternator ever since. Having said that. I also never have the generator running when my dash switch is on dual or mom. ( obviously I would have to hold the mom as its a spring switch.)
I believe what happened to me was the dash switch was on dual and the land line plugged in and I started the rig. (boom) alternator fried.