[rlmentz]

2nd ac clutch coil burned out on 2006 sorento. Is there a diode across the coil that could have gone bad? I have not seen any diode on any wiring diagram. There is power at the coil terminal, and the coils resistance is infinite. This is the second coil to blow out. Bought the vehicle with 80k miles knowing the AC was not working and knowing the coil was burned out. The ac worked great for about 3 weeks after replacing the coil, only to have it burn out again. The connector feels tight so I really dont think that is the problem. Anyone experience this issue?

Thanks.

 

[mattybyzf]

The AC compressor coil is a stand-alone unit. If the coil won't engage even though there is power to it at the connector, it's probably bad. Being able to explain why it went bad so quickly is a different story, but I'd start with a new coil.

 

[DavesSpectra]

If there was a diode across the coil you would have been able to read it at the connector. You might have to turn the leads around (red to black, black to red)
Because you say it reads infinite the coil is probably just another bad one.
Was the first replacement a KIA branded part or an after market one?
Either way 3 weeks is too short a period of time and there should be at least a 30 warranty on the new part. Check your car's voltage at the battery to make sure it's not too high (above 14.3v). Coils don't like higher than "normal" voltages and will usually burn and open shortly thereafter.
Could have been just a bad replacement part...
There is a recent post in the same section you posted in about a clutch failure...I found a replacement kit for him on Ebay for around $100. Look it up.
Dave

 

[rlmentz]

Diodes are placed in parallel with coils because when power is turned off to a coil, the collapsing magnetic field creates an induced voltage. The diode safely directs that momentary current safely to ground. Many other modern cars have this diode in place, and no, if the diode was bad (open), you would not be able to detect it with a multitester. The replacement coil was pulled from a 2006 sorento. I suppose its possible the replacement coil was weak to begin with, but I really doubt the same exact problem existed with 2 different coils. But, who knows.

Voltage while running is just under 14 volts. But maybe the alternator is creating a spike in the voltage every now and then.

 

[DavesSpectra]

Not telling me anything new...I'm an electronic tech with 40years under my belt.
You would be able to "see" it in conduction "if" you use an analog meter and the diode was good..Of course if the diode was open then it couldn't be seen.
Digitals suck when it comes to semiconductors so I keep both handy...

Like I said there is another post on an 06 Sorento with a bad AC clutch coil...That kinda indicates that the original OEM part was probably not of the best quality and failed.

 

[Hi-Scan Pro]

The replacement coil was pulled from a 2006 sorento. I suppose its possible the replacement coil was weak to begin with, but I really doubt the same exact problem existed with 2 different coils. But, who knows.

Quoted for lulz.

Get a NEW part.

 

[spongebob218]

... The replacement coil was pulled from a 2006 sorento...

It was a used coil? I understand your doubts on having 2 bad coils, but if the other one was used then it could have been at the end of its life as well. I'd start with a new factory part. If you tested the wiring and it is good, then you should be safe replacing the coil again.

 

[DavesSpectra]

Agreed with Hi-Scan Pro and SpongeBob218...
You got an old part that failed.
Dave