Why would the engine want to stall out while using the microwave while driving?
This is a new development, if we start the generator everything is fine.
Voltage from the alternator (measured at the isolator) 14v
Both battery banks fully charged.
Boost switch off.
Ideas?
Thanks
Frank
Frank,
Now that is a first for me but here is a couple of thoughts. It could be caused by a voltage drop below about 9 volts DC (as that is about the lowest voltage the ECM will function) on the engine batteries momentarily. Now the big question is why would the voltage on the crank batteries drop when the micro is on the coach batteries? It could be a bad isolator or voltage sensing relay (if the isolator has been changed out) or the boost relay causing the hole system to be one battery. Really this area is the only place the 2 battery systems come in contact with each other. If this is the case look at the battery cables for a good connection. Check the sense wire for the alternator along with the breaker for good connection. Check boost relay, isolator (or VSR), battery connections. I am verry interested in finding out the root cause as I ain't got much hair left to pull out.
Mike
If voltage drop is not the issue (unlikely, as chassis battery does not power the inverter), MAY BE (ya, capital MAY BE) Electromagnetic waves affecting ECU.
Can you duplicate the error while sitting still with engine on and microwave on?
Mike, I'll check the isolator by disconnecting the house batteries from it and try again.
Brett, that's way over my head... LOL
Jerre, yes, that's how I'm T/S it in the driveway.
I'll be back!
Removed the house batteries from the isolator and that isolated the problem down to the...isolator.
Ran the microwave several times, 30 seconds each, no issues.
Had one fail before on our other coach and it just stopped working, this was strange for sure.
Thanks guys
Decision time now.
If that was the case, the microwave is operating way, WAY out of spec. That's a huge distance for them to travel unless someone had seriously borked with the Faraday cage.
Problem is NOT there when generator is running per Phranko.
So could be inverter screwing with chassis voltage. Maybe bad grounds somewhere. Or boost switch stuck on.
If the OP has an M11 in his U320, I can not see how an overloaded alternator could stall an Engine with that much torque. 🤷♂️
Doesn't sound logical.
Does your battery voltage drop when the microwave kicks in? I don't think it's putting too much of a load on the engine, but I bet the voltage is dropping.
Victron Energy Argofet Battery... Amazon.com: Victron Energy Argofet Battery Isolators 200-2AC (2 Batteries... (https://www.amazon.com/dp/B00NT9MTMQ?ref=ppx_pop_mob_ap_share)
I put one of these in and it's working great.
After some guidance from the forum the house batteries were disconnected from the isolator, problem cleared.
Several options at this point and seeing what others have done is food for thought.
The Victron ArgoFET isolator (Reply #9 above) is a excellent unit. I used one for a while...until I decided I could get along fine without any isolator. See post linked below.
Just another path for your consideration.
Delco Remy 28SI Alternator Installation (https://www.foreforums.com/index.php?topic=40778.msg405081#msg405081)
This is what I use for an isolator now. Another option.
Amazon.com: Blue Sea Systems 7700 SOLENOID ML 12V RBS : Industrial & Scientific (https://www.amazon.com/Blue-Sea-Systems-7700-Battery/dp/B0016HRUPE/ref=sr_1_1_sspa?crid=2PJQT4C6UQYOG&keywords=blue%2Bsea%2Bsystems&qid=1698418422&sprefix=%2Caps%2C197&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1)
If you had revved up the engine the alternator should have kept up with the microwave consumption, but
you wouldn't have known you had a bad isolator.
[An unhelpful, off-topic response has been deleted. moderator Michelle