# Blown 5 amp fuse on Carrier System



## hvaclover (Oct 2, 2008)

You are right it is a ahort. If you have an ohm meter than start checking for the short.

Barring that you may have a bad contactor in line to what ever form of heating you are using.


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## chalkstar (Dec 25, 2008)

Thanks for your reply. I am going to get to work with a meter as soon as I can finish all my holiday festivities. What a rotten day to have your heat go out!


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## kbsparky (Sep 11, 2008)

That fuse is for _Control wiring_ only. I would check the condition of that small thermostat wire going to the outside unit. Look for signs of damage that may have been caused by mice chewing, or weed whacking -- things like that.


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## hvaclover (Oct 2, 2008)

agreed.


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## chalkstar (Dec 25, 2008)

I'll look into it and let you know what I find. Thanks!


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## chalkstar (Dec 25, 2008)

After a few days of searching (and not running my outside unit) I haven't found a short yet. We cleaned to contactor on the outside unit and tried to cycle on the heat. Now the thermostat does not go blank, but flashes a message of "HP" on the display. Any ideas? I can't seem to track this one down...


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## chalkstar (Dec 25, 2008)

Turns out the HP message was just a product of having the breakers off outside. We got the unit to kick on for a few seconds, before the fuse blew again. Afterward we found a short to ground associated with the board on the outside unit. Anyone know a good place to get parts?


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## hvaclover (Oct 2, 2008)

chalkstar said:


> Turns out the HP message was just a product of having the breakers off outside. We got the unit to kick on for a few seconds, before the fuse _*blew*_ again. Afterward we found a short to ground associated with the board on the outside unit. Anyone know a good place to get parts?



Dang those Gay electrons:laughing: always blowing something


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## swiftcat (Jul 23, 2014)

Hi Chalkstar,

I am facing the same issue as you for the carrier thermostat with blowing fuses (3 times in 2 weeks when it rained!). Would you describe the short circuit part on the control board in detail? Thank you!


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