You are here:

Heating, Air Conditioning, Fridge, HVAC/Coleman 7600 series wont call for ac


QUESTION: Hello, I have a coleman 7600 series presidenatal 2 hvac unit that wont call for ac.

ANSWER: Hi Dakota,

First thing to do is turn off the breakers for the furnace and A/C. Then remove the stat to expose the wiring terminal. Then jumper from "R" to "Y" and to "G". Turn the breakers back on, if the unit runs and starts cooling then your stat is bad. There are some other things we can check, but lets start with this. Also check the disconnect on the outside unit. Some have fuses in them, most of them don't.

Try this and get back to me.

---------- FOLLOW-UP ----------

QUESTION: OK I tried that and it does the same thing. The blower comes on and everything else works its just not sending 24 out. I checked the transformer and relays and switches. And the wire running out is good too. I. Checked for continuity and its good. I am out of ideas that's why I turned to you guys.

ANSWER: Dakota,

When you say everything else works, is your compressor and fan running? When you say " its just not sending 24V out do you mean the module in the furnace? I need more info. Is this a heat pump? Do you have 24v at the contactor?

let me know.

---------- FOLLOW-UP ----------

QUESTION: OK its not a heat pump. When I push the contacter in the. Compresser comes on with the fan. I am not getting 24 volt out side to the contacter. When I turn it on the blower comes on and it just won't send 24 out to the contacter to turn on the condenser.

Hey Dakota,

Well its good news that the compressor and fan will run. That narrows it down the the furnace module, check to see if the module has led lights that are blinking. The codes should be listed on the wiring diagram. Also check the fuse on the module, its usually 3 amps. Then put a meter on the "Y" terminal and the other lead on "common" going out to the outside unit. If you don't have 24V then your module is bad.

Let me know what happens.

Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts


Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

©2017 All rights reserved.