No gauges or panel instruments with Engine and Generator running simultaneously : new behavior

[BlueSteele]

Perhaps timing has something to do with this, I don't know, but driving in the Texas heat without generator-powered house AC has been no picnic! Two days ago, on the way to DeGray Lake ACE park in the Arkansas heat and humidity, I decided to fire up the genny and run the rooftop AC. From the console, the switch for the remote start did not light and all instruments and gauges went dead for the time that the start switch was pushed. Upon release, the console controls resumed their normal function. The generator did not crank or start. We suffered and sweat for the remaining 20 miles to the campground.

When we departed the campground a few days later, I started the generator and the AC. I turned on the engine, and it started, but I lost all electrical power to my dash panel and leveler system.  No tachometer, no oil pressure, water temp, trans temp, etc. But the engine was running and providing throttle response. I had no shift selector lights, either. Just a "LowAir" light, even though I was fully aired up. of course, I shut everything down.

I started the engine, and everything seemed normal, till I started the generator - then every panel instrument went dead.

I am stumped. This is the first behavior like this, and I am not sure where to start.

Any help would be appreciated. This Texas heat is tough. Luckily, I am sitting still with shore power for the next few days, but, I'd like to get a handle on this.

Thanks.

[Tom Cherry]

Just now, BlueSteele said:

Perhaps timing has something to do with this, I don't know, but driving in the Texas heat without generator-powered house AC has been no picnic! Two days ago, on the way to DeGray Lake ACE park in the Arkansas heat and humidity, I decided to fire up the genny and run the rooftop AC. From the console, the switch for the remote start did not light and all instruments and gauges went dead for the time that the start switch was pushed. Upon release, the console controls resumed their normal function. The generator did not crank or start. We suffered and sweat for the remaining 20 miles to the campground.

When we departed the campground a few days later, I started the generator and the AC. I turned on the engine, and it started, but I lost all electrical power to my dash panel and leveler system.  No tachometer, no oil pressure, water temp, trans temp, etc. But the engine was running and providing throttle response. I had no shift selector lights, either. Just a "LowAir" light, even though I was fully aired up. of course, I shut everything down.

I started the engine, and everything seemed normal, till I started the generator - then every panel instrument went dead.

I am stumped. This is the first behavior like this, and I am not sure where to start.

Any help would be appreciated. This Texas heat is tough. Luckily, I am sitting still with shore power for the next few days, but, I'd like to get a handle on this.

Thanks.

All I can offer is this.  There is, I believe a BAD GROUND up front.  The Generator's ground (and I say TYPICAL...as not any two Monaco's were ever built the same) runs from the Genny via a cable to the front (inside the Generator bay...  That chassis stud (or maybe a bolt, also has a cable or ground running to the Dash.  IF that connection is bad...as in it has corroded or such, then when you put a HIGH load, as in the starting current....remember the GROUND carries the SAME current at the Positive....then there is a HIGH resistance connection and the GROUND for the DASH comes up short.

Before I spent any major amount of time and trouble and hair pulling.  Follow the Dash Ground Cable to the front.  Follow the Generator Ground cable.  IF it is like it is on mine...and older coaches were all basically the same...  Generators were used on your...mine and dashes...and ALL need a GROUND cable.  So, if that connection point is bad....clean it up.  Take off the connections.  Use a wire brush to bare metal.  clean the terminals.  THEN put it back together.  BUT...only snug down the nut unil you can barely move the cables from side to side...then rotate them about 90 degrees....do each one.  That will then polish or burnish the mating surfaces so you have much better contact.  THEN tighten...  I would ALSO look at the Genny terminals.  NOW...beware, these are (Typically) bronze or copper or brass.  SO, do NOT just tighten and say....THAT'll FIX 'ER.  Some have got a little too frisky and sheared off the bolts.  SO, remove and clean each.  Clean the battery cables.  Reassemble...and do, if you can the polishing...Then tighten securely, but DO NOT put as much torque on the nuts.  Finally....follow the Dash Gauge Cable inside.  There is a Buss Bar there where there may be several smaller grounds.  Unscrew and clean the all.  

THEN....some folks have had to ADD a supplemental ground to the system.  or TWO cables.  It is best to use a GROUND WELED STUD....and run a SECOND Cable, same size as the original to the dash...  That is called "Bi-Wiring" and is an old trick for running speakers where the runs are long.  Even in short runs, it improves the fidelity....

That's my take....High Resistance ground.  While you are in a FIXING mood.  Shinny under the battery boxes.  Look for the TWO (House and Chassis) black cable(s) going to the two ground studs.  Be proactive and clean the studs and such.  That way you have a MUCH better circuit....I had issues with Genny cranking.  BAD (looked FINE) connection on the battery box grounds.  Actually just loosened and then rotated and let that work.  That was 8 or so year, maybe longer, ago....NO ISSUES since then.

 

[BlueSteele]

Thank you, Tom. Your sage advice is appreciated. I firmly believe in starting with simple solutions and graduating to the difficult. These older rigs are simpler, and I appreciate them. It's sometimes difficult to find advice that doesn't include all the fancy electronics the "newer" coaches have.

[Tom Cherry]

34 minutes ago, BlueSteele said:

Thank you, Tom. Your sage advice is appreciated. I firmly believe in starting with simple solutions and graduating to the difficult. These older rigs are simpler, and I appreciate them. It's sometimes difficult to find advice that doesn't include all the fancy electronics the "newer" coaches have.

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