Basement A/C Relay wire melted/open

[Rcdukes]

Fired up the genny and A/C to test before taking a trip this weekend and found that compressor #2 would not start. Stress level increased! Started diagnosing and after several checks found a wire had overheated to the point of melting causing an open. The wire was a simple loop wire on the relay for compressor #2.

I have posted pics to identify the affected part. I have two reasons for posting this. One: In the off chance that someone else might find the same problem on their unit. Two: Can anyone give me a reason this wire might overheat to the point of melting and causing an open? Low voltage? Poor wire/connector manufacturing? Any input is welcome.

I ran the A/C for awhile after making the repair without any problems.

Thanks,
Craig

[grtharris]

Rcdukes looks like a spade connector they will get loose sometimes over time. Once they are loose they will start heating up.

[dstinch]

Originally Posted by grtharris

Rcdukes looks like a spade connector they will get loose sometimes over time. Once they are loose they will start heating up.

That's it! tighten all the screws while your in there.

Don

[Arizona]

Yep, must have been the weakest point in the circuit. These units are so easy to get to, I look everything over one a year. The first time I did it I found the same wire off the relay burned back about an inch. I took the unit out of the Moho last year and oiled the motors and shaft bearing. It slides out with wires still connected so you can run it with the top off and check amperages.
We had to stay in Tucson last summer and our a/c worked great.

[Andrew Smith]

Where is the basement a/c heatproof
Pump relays located ? Is it in the outside access panel pass the battery / hot water heat compartment

[Andrew Smith]

2004 journey 36g Question on basement A/C Heatpump. When a/c running sometime I will be outside under the awning and here the fan/compressor kick off and on periodically. Would this be the second compressor kick off,and the first compressor running by it self?

[UFO Pilot]

Originally Posted by Andrew Smith

Where is the basement a/c heatproof
Pump relays located ? Is it in the outside access panel pass the battery / hot water heat compartment

You should start a new thread if you want the best response to your questions. A lot of people have already looked at this post and won't return to find your question hidden in the middle.

[AFChap]

Originally Posted by Andrew Smith

2004 journey 36g Question on basement A/C Heatpump. When a/c running sometime I will be outside under the awning and here the fan/compressor kick off and on periodically. Would this be the second compressor kick off,and the first compressor running by it self?

When the unit starts up it runs compressor #1 for apx 2 min. IF the temp differential is enough that compressor #2 is required the outside blower will shut down briefly while #2 kicks in.

[mcpo]

FWIW: Had the same problem except it was the No. 1 relay wire. Also found that my start caps were burning up and i replaced both of them.

[Keith K]

In my case it was the fan capacitor that shorted and burned the wiring. It managed to take out the relays and the circuit board also. At the time, I was able to order the parts direct from Airxcell - now I don't seem to be able to get past the automated menu.

[Rcdukes]

Thanks for the responses! For those that found bad start caps, was the damage obvious? Leaking? Charred? Mine looked ok.

Craig

[UFO Pilot]

Originally Posted by Rcdukes

Thanks for the responses! For those that found bad start caps, was the damage obvious? Leaking? Charred? Mine looked ok.

Craig

Both of mine were obvious. Had lightning hit right on top of us twice and then AC wouldn't start.

[DAN L]

my relay jumper wire burned up also. the relay itself was toast.
IMHO this was likely caused by running Ac with low voltage in a cg, 102v with just #1 compressor running.
I turned off the #2 system with the cb. to keep it from starting.
when the relay burned up, I switched the wiring so the #1 system actually operated the #2 compressor until I could find the parts. this was in reno, nv and the temp was over 100 deg.

[mcpo]

Originally Posted by Rcdukes

Thanks for the responses! For those that found bad start caps, was the damage obvious? Leaking? Charred? Mine looked ok.

Craig

One had the starter motor (that little thing connected to the top of the cap) burnt. Found that out because the A/C started pulling 40-58 amps on the display and started smoke checking the other start cap/motor combo. the relay was not affected.

[Duner]

I think DAN L is right on regarding low voltage and these failures.

I have the 50 amp Hughes Autoformer to boost low voltage. I hate hauling that giant boat anchor around. But in nearly 12 yrs of ownership, I still have the original starting capacitors and relays and compressors (which includes 5 yrs of fulltiming).

I also have the Progressive Industries Model EMS-HW50C Electrical Management System. Besides suppressing power surges, it will cut off the power if it gets too low or high. Several times I've had it trigger on low voltage because the 30 amp socket in the rv park was worn out, dropping voltage and creating a lot of heat and melting my 30-to-50 amp cord adapter.

In the long run, the money you invest in protection will pay for itself and you won't get stuck in your coach when it's 90+ deg outside.

Good luck,
Bill

[Rcdukes]

Thanks again for the responses. I have a progressive industries on my wish list. May need to bump it up in priority.

Take care,
Craig



Sent from my iPad using iRV2 - RV Forum

[NeilV]

Low voltage kills more breakers, motors, start caps, etc than most people realize.

In the ten years since I got my Hughes Autoformer I have not had to replace any more electrical gear in my coach. Before that blowers, switches and hard starts along with their related wiring would repeatably fail and have to be replaced. The East Coast brown outs of 2005 were especially brutal. Now the boost light comes on and everything works as it should without overheating and burning out.