Alternator Issue

GaDawgFan · 08-06-2012, 11:31 AM

Left home last Saturday for a 300 mile trip to the beach. About 50 miles into the trip I noticed that the guage for the alternator was not registering anything, it was like the engine was not even running. I had no check engine light or no check engine warning buzzer at the time. Because we were traveling during the day we continued on our trip but while we were running I kept the auxillary boost swith in the open position to add charge to the chassis batteries from running the generator.

Stayed at the beach for a week and when I left the coach cranked up with no problem and got us home. On the way home I noticed that the alternator guage was working again, but seemed was fluctuating randomely all over the guage. Normally it registers consisitantly in the middle of the normal range. Any ideas?

RickO · 08-06-2012, 01:09 PM

Before replacing the alternator I'd spend an hour or two checking and cleaning all of the electrical connections to/from it. But, sure sounds like the alternator needs to be checked.

Rick

bachler · 08-07-2012, 11:00 AM

As in proir post Check, check ,and then check it again, The most devestating thing is the ground, It is usualy bolted to the frame several places... Remove those steel bolts that like to breed rust and install stainless steel bolts and stainless star washers; 99% of the time it will cure the problem. If you run it with the gages bouncing around, The first thing that will happen is you will blow the DIODES in the alternator, That will cost any where from $150.. to $550.00 depending on which alternator you have. Connections Must be solid.. Life is good

clyon51 · 08-07-2012, 03:33 PM

Agree with previous posts. It sounds like the altermator is fine. It's the wiring to the gauge that sounds like the problem.

RMinflorida · 08-08-2012, 01:03 PM

Had same problem, had alternator checked out twice, it check out fine both times. Cleaned every connection I could find ! But still the voltage would come and go as I was driving.
I installed a new alternator from Power Masters, bumped it up to a 200 amp unit, 40 more amps then stock for under $400. I keep the old one on board for a backup.

Roadking52 · 08-09-2012, 07:10 PM

If you have a Freightliner chassis, check out posts concerning the VDU (a box that sends signals from the engine to the dash). Mine takes spells of different gages deciding to take the day off, then going back to work the next time the engine is started. Usually, it's the voltmeter, and one of the air gages and sometimes the fuel gage. Supposedly there are bad connections in the VDU that come and go. There have been posts on opening it up and resoldering connections. Replacement runs something north of $300. Might be a place to look. Mine is found under the bed just inside the engine compartment hatch.

GaDawgFan · 08-10-2012, 08:29 PM

Quote:

Originally Posted by Roadking52

If you have a Freightliner chassis, check out posts concerning the VDU (a box that sends signals from the engine to the dash). Mine takes spells of different gages deciding to take the day off, then going back to work the next time the engine is started. Usually, it's the voltmeter, and one of the air gages and sometimes the fuel gage. Supposedly there are bad connections in the VDU that come and go. There have been posts on opening it up and resoldering connections. Replacement runs something north of $300. Might be a place to look. Mine is found under the bed just inside the engine compartment hatch.

I appreciate the response. I actually did have some problems with the VDU late last year. I pulled the box and made the repairs to the solder connections as many others here have done. Before the VDU repair, all of the gauges were malfunctioning, since the repair all gauges have been functioning properly.