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Topic: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS (Read 594 times) previous topic - next topic

HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

WHEN I START MY 2005 U270COACH, THE VOLTAGE READOUT ON THE XANTREX MONITOR NEXT TO THE MICROWAVE QUICKLY CLIMBS TO OVER 16 VOLTS. WHEN I GO TO THE HOUSE BATTERY COMPARTMENT, THE BATTERIES ARE STARTING TO OVERHEAT. BECAUSE I DON'T KNOW HOW TO FIX THIS PROBLEM, WHEN I NEED TO DRIVE, I START THE COACH AND QUICKLY DISCONNECT THE NEGATIVE TERMINALS ON THE HOUSE BATTERIES.
WHEN I ARRIVE AT MY DESTINATION, I SHUT OFF THE COACH, RECONNECT THE BATTERIES, AND PLUG INTO SHORE POWER. EVERYTHING WORKS FINE WHEN PLUGGED INTO SHORE POWER.

I NOW BELIEVE IT IS POSSIBLE IT IS THE VOLTAGE SPIKES THAT CAUSED MY HWH SYSTEM, AND BLAUPUNKT REAR VIEW CAMERA AND TANK MONITOR TO GO OUT.

ANY ADVICE ON HOW I SHOULD TRY TO SOLVE THE HIGH VOLTAGE PROBLEM?

THANK YOU IN ADVANCE
2000 U270 34' WTFE Build 5756 "Ole Red"
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #1 –
You need to look at the sense wire from the alternator all the way to the breaker that the wire goes to.  The wire could be broken or corroded at the terminals.  Your voltage regulator on your alternator needs to be checked as it may have failed. This would be the first two things I would check.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #2 –
Welcome cdminccm to the Forum.  NO NEED TO SHOUT!  We will help you figure it out.

Follow Mike's suggestions - see what you find.  Until you get it sorted, drive as little as possible.  That high voltage isn't doing your start batteries any good, either.

If you DO need to travel before the problem is fixed, suggest disabling the alternator by removing the "excite" wire.  Tape the end of the wire to avoid a short.  Then, run your generator and engage your "BOOST" switch.  The generator will keep both battery sets charged whilst on the road.

Let us know what you find.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #3 –
One other comment

Yes this high voltage (16+) is most likely what killed the electronics that you mentioned.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #4 –
Had a similar problem the isolator was bad
95 U320 SE
07 GMC CANYON

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #5 –
If you are not clear on where to find the "sense wire" and the "excite" wire, try reading the concurrent thread linked below.  It contains a diagram of a 2003 alternator.  Hopefully, the connections are similar to yours.  Diagram reproduced below.  Red arrow points to "sense wire", green arrow points to "excite" wire.

Alternator trouble
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #6 –
@Pamela & Mike

Mike, is that breaker on the sense wire auto reset, or manual reset, or "blow and replace"?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #7 –
The breaker is/should be auto reset.

Seems like we posted a part number for it and the size a while back.  I will post a link as soon as I find it.

Pamela & Mike

On edit: the numbers we posted are for the breakers behind the front kick panel and do not have the mounting tab.
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #8 –
We had this same problem. We
1) replaced the sense wire, didn't fix it
2) checked the voltage regulator, didn't fix it
3) replaced the isolator, problem solved

Good luck
Robert & Linda Garnett
1999 U270 34'  , build 5539
2004 Acura MDX

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #9 –
You could safely disable the alternator by removing the excite wire, which is connected to one of the two small terminals on the alternator (the other small terminal is the sense wire).
Be sure to tape up the excite terminator so it does not touch ground which would be a direct short.
Disconnecting the output wire (heavy gauge ) of the alternator would leave the alternator producing high voltage with no load and I am not sure what that would do.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #10 –
Had the same problem, removed belt that ran alternator,  started generator [make sure inverter/charger is in charge mode] closed boost switch and drove another 500 miles till I found a place to troubleshoot.  Inverter will keep both sets of batteries charged.
Not sure of ISL setup, but make sure belt only drives alternator, or alternator and ac compressor.
Seeing you are running generator anyway, you can use roof ac's if nec.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #11 –
Quote from: P. Wyatt Sabourin –
You could safely disable the alternator by removing the excite wire, which is connected to one of the two small terminals on the alternator (the other small terminal is the sense wire).
Be sure to tape up the excite terminator so it does not touch ground which would be a direct short.
Disconnecting the output wire (heavy gauge ) of the alternator would leave the alternator producing high voltage with no load and I am not sure what that would do.
Excellent idea!  Better, and easier, than my suggestion.  This is why I love this Forum - many brains pondering the problem!

(Edited my earlier post to avoid confusing the OP)
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"
 

Re: HOUSE BATTERIES OVERHEATING. VOLTAGE SPIKES TO OVER 16 VOLTS

Reply #12 –
Any of us that have a problem with over charging need to keep an eye on the water

levels in the batteries. Over charging boils the water out and will burn up a battery

fairly quickly.

Carter-