Chassis Condenser fans Tripping Breaker

tim myers · 08-15-2022, 05:34 PM

Not sure if this is the correct place to post this or not, if not Mods feel free to move it.

Me and Cummins are going nuts working on the chassis air on my Journey. We have replaced the Expansion Valve, Filter Drier, Condenser Fan pressure switch, and the compressor hi/lo switch. the AC runs great then all of a sudden the condenser fan CB trips. The fans were amped out and are running at their specified amperage, the fans were even disconnected from the circuit and the breaker still tripped. this tells us something in the wiring.

My thought is to just install new wiring front to back. Has anyone else experienced this issue and if so what did you do to correct things.

Morich · 08-15-2022, 07:11 PM

It may be a missed point but has a weak breaker been considered?
As a very cheap and easy to replace item, I would look at it as a good try.

But then any good tech would know that so is it something that you've missed telling us?
I would want to know what the amp load looks like at the time the breaker trips?
That would be a way to tell if there is too much power being drawn or if the breaker is tripping too easily! A graphing amp meter that one could hook to the breaker load and let it print out a trace of the load up to the point the breaker trips would be a good item.
Think of it as a meter which gives not only a number but also draws a trace of the level at any given time. A graphing thermometer is likely a more well known item?

This is one which does way more than likely ever needed on auto/ RV repair but easy enough to find:
https://www.walmart.com/ip/Siglent-T...-RMS/922719877

I had this discussion with several Ford garages on an intermitant problem and I did not want to accept "something" in the wiring as a logical reason for not finding the problem!

There are actually very few "somethings" to check. They are called shorts, grounds, opens, and crosses! But one has to use a meter to test the wiring as it does not show up when just looking at things.

But there are even fewer mechanical techs who want to know much about electrical testing!

tim myers · 08-15-2022, 07:26 PM

short answer is yes a weak breaker was discussed, but in my mind with no load even a weak breaker shouldn't trip.

Good news is that when I told them I had wiring diagrams they asked me to send them over so they could go over them, that's a start.

Morich · 08-15-2022, 07:35 PM

Quote:

Originally Posted by tim myers

short answer is yes a weak breaker was discussed, but in my mind with no load even a weak breaker shouldn't trip.

Good news is that when I told them I had wiring diagrams they asked me to send them over so they could go over them, that's a start.

Sounds right if you've got them thinking out of the normal things they change.

Small point they might look for is a cracked breaker can do weird things.

tim myers · 08-15-2022, 08:35 PM

wish me luck, we had to use the coach AC and Generator on this trip, will give them another chance next week

tim myers · 08-25-2022, 03:14 PM

The issue is resolved. Cummins gave everything a good looking over and discovered burnt wires back near the condenser fans. Looks like at some point the Adel Clamp let go and the harness (6 wires) fell close to the exhaust. Someone used zip ties to pull the harness back up but the damage had already been done. Fast forward to us putting about 9000 miles on our new to us DP and the scorched insulation starts falling off exposing bare wire. Three of the six wires had bare wire. Cummins cut out the bad section and re-wired, provided some heat shielding and reattached the harness up out of harms way. Now the condenser fans work with no issues.

I also had a thread from awhile back regarding a breaker feeding my Compartment lights that keep tripping. I am hopeful that this wire also ran in this harness and that this issue is also resolved now.

I tried to get the Winnebago wire identifiers off of the wire but they were too badly burnt. Will post a picture of them here.

Morich · 08-25-2022, 04:02 PM

Argh!
And all that trouble could have been prevented with doing the work right when they had the first problem!

All's well that ends well, they say, but the trip can kill you !!

tim myers · 08-25-2022, 06:31 PM

I will report back to the other thread about the Compartment lights if this inf act fixes them. I should know by the time I get back from the UP. May give some others things to look for. Really wish I could see the identification codes on the wires. If the Compartment lights are fixed that would be two of the wires, no idea what the third bare wife goes to.

Morich · 08-25-2022, 08:44 PM

Just for those who wonder while they wander?

Any chance that you could spot the wire bundle by location of where they were found and compare it to the "12 Volt installation drawings"?
It would have to be somebody who knows your Rv much better than I ever will as I do not know where the even condenser fans would show up!

Something like this info to locate/ID the burned wires?

Click image for larger version

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Combined with this drawing set?

https://www.winnebago.com/Files/File...ire_157290.pdf

tim myers · 08-26-2022, 01:29 PM

I crawled under the Journey this morning, and I think I found where the repair was made. Good on the technician to find this, I am not sure I would have ever noticed it.

In the attached picture you can see the large under bed access and what appears to be new wire conduit, nice and shiny black. This runs above what looks like a semi flexible exhaust pipe of some sort, kinda looks like a bellows. I think this is where harness fell and was damaged.

Cummins is supposed to send me pictures of the damaged wire, but they have not yet forwarded it.

Morich · 08-26-2022, 02:18 PM

Finding it is a major plusand it may have been really good timing as the other wires in the bundle may have been far more trouble than compartment lights, if this wild guess is right?

If this is where your bed is and the correct group of wires, there are some others that seem in the same bundle which might have been more awkward to deal with them going out?
This is far from the best drawing to make sense of but it looks like the water heater and furnace may have been close to failing , too??

tim myers · 08-27-2022, 06:43 AM

Funny you mentioned that, WH gave me some issues a year ago that resolved itself, or did it. Definitely 3 bare wires. The other three were intact just crispy.

Morich · 08-27-2022, 08:48 AM

That's a pretty crude drawing and not at all sure it fits but it does show there are other wires in the same run which may have hurt far worse if they failed while on a trip.

My thought is that if one had near that same model RV, I might favor looking at the location for those wires and see if there was something I could do like add a strap or cover to keep those wires off the hot stuff!

Being aware is often the first part of avoiding disasters! Most of us tie our shoe laces so why not check the wires before they let you down?

tim myers · 08-27-2022, 10:13 AM

Very True, and these wires are very easily accessed if you pull the large engine cover that is under the bed. My technician did this work from the floor of the shop bu sitting up in some free space. The four corner lifts were broken at this Cummins service center. So all in the repair of the AC system consisted of a new TXV, Filter/Drier, Condenser fan pressure switch, two evacuations and re-charges of the system, and the wiring repair.

I still need to replace the Binary pressure switch that protects the compressor, switch coming Monday.

Plus the departure of around $2000.
I agree that I may have dodged a bigger bullet with the wiring issue. Plus I am going to go out and double check a few systems in the Journey, sometimes repairs can cause issues just as well as fix them.