RV A/C

[adamcf]

When I got back to the rv today after work I smelled something similar to burnt electronics and the source seems to be my back AC vent.

The AC was still running and blowing air but it smelled rather bad

I shut it off and removed the shroud.

No obvious burned components but also no idea what I'm looking for.

The unit still kicks on and off.

It's a coleman mach, 7000 or 8000 series.

Called AC repair guy and said he can come out for quite a bit of money so I'm wonder if there is anything I can look at or investigate before resorting to repair costs.

[Xmcdog]

Originally Posted by adamcf

When I got back to the rv today after work I smelled something similar to burnt electronics and the source seems to be my back AC vent.

The AC was still running and blowing air but it smelled rather bad

I shut it off and removed the shroud.

No obvious burned components but also no idea what I'm looking for.

The unit still kicks on and off.

It's a coleman mach, 7000 or 8000 series.

Called AC repair guy and said he can come out for quite a bit of money so I'm wonder if there is anything I can look at or investigate before resorting to repair costs.

Usually the electrical stuff is isolated from the inside airflow. Having said that it is possible the capacitor or fan motor is on the way out.

More likely is the PC board inside under the grill. It may or may not have one.

Also are you sure it is coming from the A/C itself? Years ago I chased a burnt electrical smell that appeared to be A/C related. This was in a bank with a ducted system. After several hours we found a burnt out computer located near the return air intake.

[adamcf]

I am not positive it is the ac but I don't smell it with that ac off.

When I turn that ac on the smell comes through the rear vents pretty heavily.

[96 Wideglide]

Roof A/C capacitors often die a smelly death.

[adamcf]

Where would I find the part number for that and maybe a tutorial on how to replace?

[hypoxia]

A common thing to go bad and smell bad is the PTCR. http://www.tiffinrvnetwork.com/crusingator/P/P-090.pdf In theory you shouldn't be able to smell it but RV's are not sealed the best. Run the unit while on the roof with the cover off & see if you smell it. There are other boards that can have a bad part on them, it's just not as common.

The capacitor values will be stamped on them. It's a good idea to write them down and get spares as they are the #1 thing to cause failure. https://www.marsdelivers.com/wps/wcm...e-ca911432dc10

[adamcf]

Did a bit more digging and found the source of the smell.

So now it's time to replace the obvious and go from there.

I found some documentation from the previous owner and I found an air conditioner packet that says it's a model: 8632-8764

The smell is definitely coming from the capacitor bank and starting circuit mentioned above and is blatantly obvious from the pictures attached.

Now, does anyone have a resource for good parts, I assume this isn't something ace or big box stores carry.

Granted this charred part could have caused problems further down the line ie compressor.

Thanks for any additional help

[adamcf]

https://pdxrvwholesale.com/products/...-capacitor-kit

I found this kit online

[iowaone]

This is a helpful store.

[ArtJoyce]

Originally Posted by 96 Wideglide

Roof A/C capacitors often die a smelly death.

But when they die, the fan or compressor will not run?

[adamcf]

To me it looks like whatever the top piece of that capacitor is was the failure point so maybe its not all the way dead yet?

Can anyone verify that the kit I linked would work?

I am finding 30 and 45 uf caps but the part was so rusted that i can barely see any numbers on it.

I think the other two are equivalent part numbers so im pretty sure that kit or equivalent would work for at least a part swap

Amazon seemed to have the same parts sold separately for roughly the same price.

[adamcf]

What's left of the lettering

[hypoxia]

The PTCR is the obvious problem. The capacitors according to PDX are 30 uf for the compressor and 7.5 uf for the fan. My RV lives in the desert so I advocate 440 volt capacitors instead of 370 volts. If you replace just the PTCR it will probably cure your problem. Your capacitors may be OK. I would want spares regardless. You can opt to replace the PTCR with a Supco SPP6 https://www.supco.com/web/supco_live/products/SPP6.html which takes up more space. You can also replace the capacitors with a 30/7.5 uf capacitor which will give you more space.

Personally, I recommend getting a multimeter which measures capacitance as well as DC amps. Unless you want to fund vacations for repair shops, knowing how to use that meter will save you a lot of grief and moola.

Do NOT get made in China capacitors. They will fail prematurely.

[96 Wideglide]

Originally Posted by ArtJoyce

But when they die, the fan or compressor will not run?

When my PTCR and start capacitor failed, the fan would still run, and you could hear the compressor trying to run about every minute.