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SteveG · 05-02-2012, 02:07 PM

A friend traveling from Florida to Idaho in his 2012 Holiday Rambler Ambassador had an odd problem which he asked me to post for him as it might save someone some grief.

While traveling during a horrific rain storm the high voltage warning lamp turned on; then the ABS warning lamp, then the DPF lamp and none of the computer outputs (miles per gallon, distance etc) worked. The Navstar Maxxforce 10 diesel engine continued to operate. But with the DPF warning lamp basically saying you have to have this serviced he did not know how much engine operation time he had.

He was in La Salle, ILL when this occurred. He pulled into an International Truck place but it is a franchise and they did not do RVs. He coordinated with Alliance in Florida and Monaco in Oregon and they found him an International Truck dealer in Joliet, IL. This required that they back track 42 miles. The dealer said he would fit him in immediately but again they did not do RV work so he will have to pay and then be reimbursed by Monaco. Everyone agreed to this so work immediately proceeded.

After downloading the codes and making some test the mechanic tested the Alternator at both low RPM and a higher RPM. At low RPM the output was normal. At high RPM the output had voltage spikes. The theory is that the spikes blew up some of the electronics. I was not told why the mechanic suspected the alternator. They are trucking in an alternator this afternoon and will replace the “high voltage” warning board under the dash as they believe this board was damaged by a voltage spike; they will reset the DPF system, maybe have to replace the sensor not sure at this point. Tom did not comment on the ABS brake sensor so not sure if it just reset by itself.

The question in Tom’s mind is what caused the alternator at around 9,000 miles to fail. Did traveling through the torrential rain storm somehow force water into the alternator? Or was the failure just coincidence? If anyone else has had this problem Tom would appreciate hearing from you.

They are hoping that sometime tomorrow they will be again heading west. SteveG

Confusion · 05-02-2012, 02:22 PM

Quote:

Originally Posted by SteveG

A friend traveling from Florida to Idaho in his 2012 Holiday Rambler Ambassador had an odd problem which he asked me to post for him as it might save someone some grief.

While traveling during a horrific rain storm the high voltage warning lamp turned on; then the ABS warning lamp, then the DPF lamp and none of the computer outputs (miles per gallon, distance etc) worked. The Navstar Maxxforce 10 diesel engine continued to operate. But with the DPF warning lamp basically saying you have to have this serviced he did not know how much engine operation time he had.

He was in La Salle, ILL when this occurred. He pulled into an International Truck place but it is a franchise and they did not do RVs. He coordinated with Alliance in Florida and Monaco in Oregon and they found him an International Truck dealer in Joliet, IL. This required that they back track 42 miles. The dealer said he would fit him in immediately but again they did not do RV work so he will have to pay and then be reimbursed by Monaco. Everyone agreed to this so work immediately proceeded.

After downloading the codes and making some test the mechanic tested the Alternator at both low RPM and a higher RPM. At low RPM the output was normal. At high RPM the output had voltage spikes. The theory is that the spikes blew up some of the electronics. I was not told why the mechanic suspected the alternator. They are trucking in an alternator this afternoon and will replace the “high voltage” warning board under the dash as they believe this board was damaged by a voltage spike; they will reset the DPF system, maybe have to replace the sensor not sure at this point. Tom did not comment on the ABS brake sensor so not sure if it just reset by itself.

The question in Tom’s mind is what caused the alternator at around 9,000 miles to fail. Did traveling through the torrential rain storm somehow force water into the alternator? Or was the failure just coincidence? If anyone else has had this problem Tom would appreciate hearing from you.

They are hoping that sometime tomorrow they will be again heading west. SteveG

Had the same thing happen last summer on a 2006 Cummins ISC with 20k miles on it. I know, not a Navistar but the voltage regulator fried itself while driving in a heavy rainstorm. ABS light came on, dash lights got REALLY bright, volt meter pegged. It would go back to normal then spike again. Within a few miles I pulled into a truckstop and had the alternator replaced. According to the shop the regulator cannot be replaced separate from the alternator. Total cost was ~$450 in cash. My only casualty was a crappy GPS that the PO had installed.

I've had the same symptoms happen on old vehicles so I recognized the symptoms and knew to stop driving ASAP. Overvoltage is not good for electrical bits.

If I hadn't found a shop that had the appropriate alternator in stock and was able to replace it for a fair price I would have just unhooked the +12v feed to the alternator and run the generator to keep the house and coach batteries charged.

SteveG · 05-03-2012, 04:55 AM

Thanks for the reply. So far Tom has not found any damage of GPS, dash radio etc. I'll remind him to double check.

Doesn't the Alternator typically charge the engine batteries and the house batteries? If so, when a voltage spike hits the system from the alternator can the spike damage the convertor or is it somehow isolated?

Also, when the generator is running while you are driving down the road does the generator thru the converter or the alternator charge the house batteries? I am assuming the transfer switch is set up to make the choice?

I think I am correct when I say that when driving down the road and the inverter is operating the alternator is charging the house batteries? If this is correct then the inverter is potentially subject to damage from an alternator voltage spike? Or does it have some kind of built in protection that would isolate it?

Just not something I have thought about before. Thanks, SteveG

Confusion · 05-03-2012, 06:59 PM

Quote:

Originally Posted by SteveG

Thanks for the reply. So far Tom has not found any damage of GPS, dash radio etc. I'll remind him to double check.

Doesn't the Alternator typically charge the engine batteries and the house batteries? If so, when a voltage spike hits the system from the alternator can the spike damage the convertor or is it somehow isolated?

Also, when the generator is running while you are driving down the road does the generator thru the converter or the alternator charge the house batteries? I am assuming the transfer switch is set up to make the choice?

I think I am correct when I say that when driving down the road and the inverter is operating the alternator is charging the house batteries? If this is correct then the inverter is potentially subject to damage from an alternator voltage spike? Or does it have some kind of built in protection that would isolate it?

Just not something I have thought about before. Thanks, SteveG

Some RVs have what is called a BIRD relay that will allow the alternator to charge the house batteries after the coach batteries are charged. If mine has one it doesn't work so for me to tie the house and coach batteries together I hit the emergency switch and wedge a dime into it so it stays in the activated position.

The transfer switch only switches between generator and shore power so I don't believe it would affect the 12 volt charging system. I believe the inverter would rely on its internal protection circuitry to keep it save during a power surge but I really don't know.