Replacing air conditioner capacitors

[makemglow]

had massive white smoke w burn smell coming from reat ac vents. shut power to ac off. went on roof to check ac and capacitors. one capacitor, there are 3, had the top blown off with melted wiring insulation. 2nd one had melted insulation. 3rd one seemed ok visually. Fan mptor worked but obviously no ac cooling. my question should i find replacement capacitors and tape the burn spots on the insulation and pray that works or just replace the ac. 2002 bounder w coleman mach ac

[Oldelevatorman]

I’d replace the unit. Nor would I use anything that had been burned also. Don’t know if it’d be worth re-wiring since it’s so old anyway.

[paddler1954]

It really depends on the state of your wallet and how well the rear AC was working before it blew. If you have the skill set, buying new caps and replacing the burnt wires would be the cheapest option. If you have to pay someone to do the work, you're probably looking at parts plus $200 or so. Replacing the AC unit would obviously be the most expensive option but it would guarantee a good working AC for many years to come. What's in your wallet?

[triplewide]

Three capacitors, sounds like you may have had a "hard start kit" installed on the AC. Check the wiring diagram, if still visible. May only require 2 capacitors. Check to see if there are any "burn" marks on the case or body of the ac where wiring may have rubbed causing a short.

Like Paddler posted, depends on how much you want to spend. You can replace the unit yourself for under a thousand. Or take a chance on repair for around $75 yourself. If you will worry about the repaired AC unit as you use the camper, then replace it like Oldelevatorman suggested. Some times peace of mind is priceless.

[cwit]

I would replace unit.

[timjet]

Repair or replace, it's a tough decision. Here's why I think so. The new AC units aren't made with the same materials as the older ones and seem to fail sooner. So you may spend $1500 to replace it only to have it fail in 2-3 years. Search AC failure or similar on this forum and you'll get the idea.

If you can replace the caps and wiring yourself, that might be a good gamble. You might be throwing away $75 bucks, but I would probably take that gamble. Just make sure you ground the old caps before messing with them.
I've always felt that if it costs half as much or more to repair I would replace. But your AC is 16 yo, probably nearing it's life expectancy.

[Kennzz05]

Originally Posted by triplewide

Three capacitors, sounds like you may have had a "hard start kit" installed on the AC. Check the wiring diagram, if still visible. May only require 2 capacitors. Check to see if there are any "burn" marks on the case or body of the ac where wiring may have rubbed causing a short.

Like Paddler posted, depends on how much you want to spend. You can replace the unit yourself for under a thousand. Or take a chance on repair for around $75 yourself. If you will worry about the repaired AC unit as you use the camper, then replace it like Oldelevatorman suggested. Some times peace of mind is priceless.

Capacitors blow...sometimes for no apparent reason(many times it's a loose connection ...sometimes because the compressor locked up. If your comfortable order the parts splice the wires and let ER rip. Worst case scenario you waste 35 bucks and your time and end up doing the ac anyway

[Big_Tom]

There is a thorough 12 minute YouTube video that outlines the process of changing the AC fan motor as well as the capacitors. This will give you a good idea of the procedure.
"Coleman Motor replacement - Donald McAdams"


My fan motor locked up so I changed both motor and all three caps on my front rooftop AC unit.

There are many capacitors sold online so be sure you get the proper replacements if you tackle this project.

BigTom

[Domo]

Originally Posted by Kennzz05

Capacitors blow...sometimes for no apparent reason(many times it's a loose connection ...sometimes because the compressor locked up. If your comfortable order the parts splice the wires and let ER rip. Worst case scenario you waste 35 bucks and your time and end up doing the ac anyway

+1 - definitely YES capacitors blow out - that's why they're replaceable. They also die in computer monitors, microwaves and every other device.

[Gary RVRoamer]

I'm trying to figure out how blown capacitors caused smoke to come out inside the RV. There is no air path from the exterior (where the capacitors are) to the inside ducting. There is only a heat exchanger. If you had white smoke inside, I'm thinking something more serious than the caps happened. The caps may have failed because of some other problem, e.g. really high voltage (as might happen on 50A power with a open neutral wire).

[makemglow]

Originally Posted by Gary RVRoamer

I'm trying to figure out how blown capacitors caused smoke to come out inside the RV. There is no air path from the exterior (where the capacitors are) to the inside ducting. There is only a heat exchanger. If you had white smoke inside, I'm thinking something more serious than the caps happened. The caps may have failed because of some other problem, e.g. really high voltage (as might happen on 50A power with a open neutral wire).

ac fan blows air from condenser down thru duct under ac to inside. i'm guessing enough smoke was emitted from capacitor to be sucked in by fan and then down to inside. will probably replace entire unit and there won't be any question of what's in my wallet. moths.

[KanzKran]

Originally Posted by Gary RVRoamer

I'm trying to figure out how blown capacitors caused smoke to come out inside the RV. There is no air path from the exterior (where the capacitors are) to the inside ducting.

Is the motor in the air stream? It may have burned a winding when the caps let go.

[makemglow]

Originally Posted by KanzKran

Is the motor in the air stream? It may have burned a winding when the caps let go.

motor has a long shaft with blades in a shroud. has to get air from somewhere to blow inside.

[makemglow]

Originally Posted by KanzKran

Is the motor in the air stream? It may have burned a winding when the caps let go.

fan works. just no ac.