2008 Chevy Express 3500 Intermittent Charging Warning

[GroupB]

4 hours into a trip stopped for lunch. A short time later started vehicle to continue. A mile later “charge not working” and battery light on. 12.2V on SCANGAGE volt meter. After 15 minutes went up to about 14V. Message went off; shortly after light went out. Continued to our campsite. Have not tried it since. Will be leaving Thursday for home.

2008 Chevy express 3500. 6.0 L 100,000 miles, original alternator and isolator. Disconnected chassis battery when we stopped and it’s sitting at 12.9 V now.

Any similar experience or suggestions?

 

[booster]

4 hours into a trip stopped for lunch. A short time later started vehicle to continue. A mile later “charge not working” and battery light on. 12.2V on SCANGAGE volt meter. After 15 minutes went up to about 14V. Message went off; shortly after light went out. Continued to our campsite. Have not tried it since. Will be leaving Thursday for home.

2008 Chevy express 3500. 6.0 L 100,000 miles, original alternator and isolator. Disconnected chassis battery when we stopped and it’s sitting at 12.9 V now.

Any similar experience or suggestions?

Are you sure it has an isolator which is a diode based unit and not an automatic charge relay/separator. Which it is can make a difference on some models. My guess is that it is the separator type as that should be stock on a 2008 Roadtrek.

Take a look at the firewall just off center to the driver side under the hood and look for a round cylindrical item with a squarish box on it and two heavy cables attached, plus some smaller wires.

With a separator, it would mostly eliminate it as an issue for the Scangauge to see.

It sounds like you may have a loose cable at the battery, alternator or block. Carefully remove and clean all of the contacting areas and make sure the go back together tightly. Hopefully, that will fix it as the next step would be connections from the PCM to alternator as long as it is a 2008 chassis which is the first year for the PCM controlled alternators in the vans.

 

[TX-Trek]

In addition to the advice above, suggest to clean ground points as well. Corroded grounds can cause all sorts of strange issues.
After purchase of our 2010 210P, I went over all pos and neg connections - all grounds, circuit breakers etc. Including the circuit breaker run under the van above the genset. Lots of dirt. I've also replaced the original battery isolator with a Blue Sea auto battery relay. Its a magnetic latching unlike the original heat creating relay that needs constant power to stay latched.

 

[GroupB]

Good suggestions. I was condemning the alternator but couldn’t see how a failure would reverse itself. A bad connection makes sense.

It has an isolator. Red rectangular box with cooling fins. 08 Roadtrek on an 08 chassis. My understanding is RT would use leftover parts on the next model year if it was invisible to the customer. I’ve come across this on several cars over the years.

 

[TX-Trek]

The LS series drivetrain are a bit notorious about grounds. We've got a 2010 Silverado that I added more robust grounding than the factory and I've done the same with our RT. Theres actually kits available but I used my own cables, etc.