Help My Thermostats Wont Come On After Surger

[Lhinkle114]

I want to thank everyone that responds to this post ahead of time. We had a huge electrical DC surge that fried almost all 12V items. But I have fixed most and am stuck on my thermostats. We have a 3791RD with Microair theromstats installed. After the electrical surge both thermostats wont come one. I have checked all the fuses in the control center and there are fine. What should I be looking at next?

Thanks Ahead Time
Larry

[jsb5717]

Did you replace the TStats and they won't work or were these installed during the surge? If other components were wrecked these could be as well. You might contact Micro Aire.

You should also look into an EMS system to help prevent this kind of thing.

[Lhinkle114]

We had a Hughes Surge Protector but the surge came from the converter internally and was not detected by the bull dog and I tried new thermostats but still no power on either one. Is there a hidden fuse somewhere?

[jsb5717]

Hmmm...that sucks. How do you get a DC surge? Converter go bad and do damage?

Do you have a volt meter to check the wiring behind the TStat to see if you're getting 12v there? I assume you've checked all of the other fuses? (edit: I see you did that) Do you have any resettable 12v fuses? You might swap those out for standard ones.

[jsb5717]

Sorry, disjointed thoughts.

So I assume you have a new converter and other 12v items are working?

[Lhinkle114]

Tomorrow I will change the standard fuse with a new fuse to see it that fixes it and test the voltage. Is there a control board somewhere that might have a fuse that can be reset up near the air unit

[jsb5717]

One more:

Have you pulled the power center out and checked to see if there are any burns/melted wires on it?

[Lhinkle114]

Yes almost all 12V items were lost hydraulics, slides, converter, pump, Fans and about everything. This is just one step in my repair process. I have repaired all the slide motors and controllers then the hydraulic slides and controllers. If you think of anything to fix this I would greatly appreciate the help.

[Lhinkle114]

Yes we did that and tightened all the connections and grounds

[rohrmann]

You need to verify that the 12 volt auto reset breakers on the wall behind the batteries have power on both sides of the breakers.

[Lhinkle114]

I will do that today

[ChuckS]

I would start my troubleshooting efforts with those thermostats by verifying if there is any 12 VDC to each one..

They are fed their 12 volt power separately via the gateway and roof mounted control module

If you have NO 12 volts DC at either thermostat then you will need to check both gateways to see if they have 12 VDC..

If they dont then most likely neither do each of the control boxes for each roof A/C unit

link to your thermostat manual if you don't have it to help verify power at thermostats..

http://www.micro-air.com/support-doc...Manual_1.5.pdf

With no 12 volt power up on the roof to either A/C unit noting will work till you resolve loss of 12V vdc

[Lhinkle114]

Thank you check, the manual will help. Also, do you happen to know? Is there a fuse on these control boards up on the air conditioner as you called the gateways?

[ChuckS]

I would check first to see if you have 12 volts to the gateways ..if not you will have to locate their feed source and fix first.

Image of typical gateway for your Coleman A/C units

[Lhinkle114]

Thanks for the help I have been trying to find a picture of the dometic blizzard control gateway yet