I post a question on a contact relay switch on my unit on my mobile home. A nice helper answer my question but still looking for answer . If I'm inside the house and turn on the air conditon it blow no cold air my fan does not work on auto or on position . We check outside open it and found this contact relay switch . When press by hand the fan will work and turn on .the helper that answer my question said might have a bug inside but we don't see it or we just don't know how to find it. Question is do we need to buy a new one ?is easy to put it on?or there is something else going on my unit. Trying to save money is so expensive to call professional for something that we can possibly do. Need help thanks a lot

The contact relay is a very common part to go bad. If yours only works when you press on it - you definitely need to replace this part. As far as how easy it is I don't know as I don't do my own a/c repairs - I just troubleshoot the problems and call in the pros to fix for me and properly test the unit. If you turn off all the electric in your home at the main breaker and then take the relay switch out, you should be able to put the new one in following the same procedure you did when taking it out in the first place only reverse the order of everything. Relays need to match exactly so be sure you get the SAME brand, etc as the one that's in your unit.

Your post is very difficult to follow for the following reasons:

There are multiple fans. The outside and inside unit have one.
There are/can be multiple contactors. Outside and inside.
There are heat/cool modes and fan modes of auto/on.

We need to know exactly what's not working.

An outside unit not turning on when the inside unit is, can mean that the low-pressure switch senses that there is too little refrigerent in the system, for instance.

I'll address the relay only. When the fan should be energized, is there voltage to the coil? If so, check the coils continuity. Do this by turning off the power and disconnecting one side of the coil. If you are unable to do this troubleshooting, leave it to someone familiar with HVAC equipment... professionals.

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Originally Posted by twinkiedooter

The contact relay is a very common part to go bad. If yours only works when you press on it - you definitely need to replace this part. As far as how easy it is I don't know as i don't do my own a/c repairs - I just troubleshoot the problems and call in the pros to fix for me and properly test the unit. If you turn off all the electric in your home at the main breaker and then take the relay switch out, you should be able to put the new one in following the same procedure you did when taking it out in the first place only reverse the order of everything. Relays need to match exactly so be sure you get the SAME brand, etc as the one that's in your unit.

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Thank you so much

I have the same problem. After the new contact switch was replaced, it still did not work. When I measured the voltage on either side of the switch, they gave the same reading: 25 volts. Could any one help me solve this problem. I am about to call professional to figure it out.