Community Forums

BigDBright · 08-08-2014, 08:43 PM

I have a 2000 Itasca Horizon 36' motorhome that I recently bought. I'm having a problem with the generator powering up the coach on a reliable basis. On shore power, everything works flawlessly every time. The problems start when I go to use the generator for power. 100% of the time, the gen will start right up, go to high idle for a minute or two, drop down to a medium idle for a bit, then drop to a low idle after everything evens out. About 60% of the time, the power display board will come on, showing the amps in, the a.c. draw, power share, etc. just like it should. The remaining 40% of the time absolutely nothing happens at the board. I'm suspecting (with my admittedly limited knowledge) that there must be a power share switch that changes from shore power to gen power.
My question is this; where would I go to look on the coach for this switch, if it exists, and if it's there and bad, where would I go to find a replacement?
It's a darn good thing I got a screaming deal on the coach, because I've sure found out how little I know about a whole lot of things in a very short amount of time!

BFlinn181 · 08-08-2014, 08:58 PM

It's called an Automatic Transfer Switch. Trace your shore cord, it will go to the switch after entering the coach. It's not unusual for the large gauge wires that carry the power, to get loose in the clamps that hook up to the ATS. Turn off power, open the box, and tighten all the clamps holding the wires. The ATS is usually programmed to delay connecting to the generator about 20-30 seconds so the generator has time to stabilize power output.

BigDBright · 08-09-2014, 12:45 PM

Thanks!! I went over to the storage unit and opened the door where the cord is stored. I did exactly as you suggested; followed the shore cord up to the box it disappeared into. Guess what it is called? Automatic Transfer Switch. LOL. Imagine that? Removed the cover and tightened every single set screw. I could get just a little movement from all but one green (earth?) wire. That one I got about 1/2 turn out of. I had my sweetie fire the gen up as I watched/listened, and sure enough, after about 30 seconds there was a semi-loud click and a green light came on on a circuit board inside. I hear an excited "It's on!!" from my wife who was inside watching the display. I had her shut it off, covered the box back up and picked everything up, then went inside to close things up before leaving. Just for grins and giggles, I fired the gen back up, and 30 seconds later it was alive again. I realize it's only 2 for 2, but I'm encouraged, at least. I also took a pic of the box cover so I could show it to a parts guy if needed should I have to buy a replacement down the road. Thanks again for the suggestions.

BFlinn181 · 08-09-2014, 12:56 PM

Thanks for reporting back, I'm glad it was something simple!

Bob

Chaffeekid · 08-11-2014, 05:39 AM

Ok, glad that worked, here's another area to check on your generator. When you are looking at the top front of the Genset, you will note a small metal cover on the left hand side, held on by four screws.

Make sure the unit is unplugged from shore power, and the generator is OFF. Remove the four screws and remove the cover plate. Look down there with a flashlight. You should see a transfer block, where the wires from the generator are connected to the coach wiring.

When I was having the no power to the coach, this transfer block was completely covered in corrosion. If yours was like mine you will probably need to get a new block, mine was so bad that the locking screws for the wires were completely eaten away. Once I reconnected the wires, the generator has ran flawlessly for the past two years. Take a picture of the connectors with your cell phone to insure that you connect the wires correctly on reinstallation.

Hope this helps
Jim

BigDBright · 08-12-2014, 06:20 AM

Thanks, Gunny! I'll definitely take a look at that.
And thank you for your service to our country.

wa8yxm · 08-12-2014, 10:04 AM

I am fond of saying many RVers have a few screws loose.. Glad you tightened up one of yours.. Other Screws I have tightened

Breaker to wire in breaker box.. Bus bar to wire (Same box)
marinco outlet (2 of them, not mine) on shore cord, Marinco inlet (Mine).

Whoever tightens down the electrical screws.. I think my Grandson could do a better job (He is about 40 days old)

BFlinn181 · 08-12-2014, 10:31 AM

Quote:

Originally Posted by wa8yxm

I am fond of saying many RVers have a few screws loose.. Glad you tightened up one of yours.. Other Screws I have tightened

Breaker to wire in breaker box.. Bus bar to wire (Same box)
marinco outlet (2 of them, not mine) on shore cord, Marinco inlet (Mine).

Whoever tightens down the electrical screws.. I think my Grandson could do a better job (He is about 40 days old)

In most cases the wires were tight when the RV left the factory. A stranded wire under constant clamp pressure AND VIBRATION shaking down the highway can allow the strands of copper (soft metal) to shift or flatten allowing the pressure to loosen. Try clamping a 6 gauge wire. Tighten, then wiggle the wire a little and I bet you can tighten it further. Tightening clamped wires should be a part of everyone's maintenance.

HORNETD · 08-13-2014, 09:04 PM

Don't over tighten the terminations or you will break individual strands of the wire. A Harbor Freight torque wrench may be a good idea for checking the connections in order to avoid over tightening.

--
Tom

TwelveVolt · 08-14-2014, 06:39 AM

Quote:

Originally Posted by HORNETD

Don't over tighten the terminations or you will break individual strands of the wire. A Harbor Freight torque wrench may be a good idea for checking the connections in order to avoid over tightening.

--
Tom

Excellent idea. Is there a published list of torque settings?

I am in the process of replacing all the screws on my ground and neutral strips because the heads are breaking apart when I tighten them.

Does anybody use a corrosion blocker product on these components?

HORNETD · 08-14-2014, 06:51 AM

The torque settings are called out in the manufacturers instructions and in the labeling on the device itself if it is UL listed.

BFlinn181 · 08-14-2014, 09:59 AM

You're trying to get a good conductive path for the electricity. It's not like you're tightening a bridge cable. When I suggested you can wiggle the wire and tighten it further I was just illustrating why they come loose over time. Over tightening doesn't mean you've extended interval before checking the next time. I make the terminal clamp firm, not metal distorting, thread stripping, strand breaking tight!