USA Toll Free: 1-866-536-6691

World's Largest Forum Dedicated To Lennox Comfort Products| Over 22,000 Posts!
| Helping Lennox Owners & Servicers Everyday!
Visit Our Lennox Parts Store

Service Forum for Lennox HVAC Owners and Servicers.

Lennox
 All Forums
 Repairing and Servicing Lennox Products
 Repairing / Servicing Lennox Gas Furnaces
 Fan Relay Test Procedure
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

tgrill

3 Posts

Posted - 06/10/2008 :  10:49:42 PM  Show Profile  Reply with Quote
Is there procedure to test a fan relay? I'd like to confirm that my P-8-10283 relay for my G14Q3-60-1 Pulse furnace is bad before replacing it. My P-8-9490 transformer fried when I turned my thermostat to cool. I've checked for shortages in the wiring, but have found none which leads me to believe it could be the relay.

Cozy.Support

5895 Posts

Posted - 06/11/2008 :  07:21:19 AM  Show Profile  Reply with Quote
Just use an ohm meter or continuity tester to test the N.C. connections. Then energize the relay to test the N.O. connections. This is not a 100% indication that the relay is good, because pitted/burned contact point may make connection one time, and not the next.



Cozy.Support does not provide a diagnosis for users of this forum. We do, however, try to provide information that will help servicers arrive at their own diagnosis.

Once you know what part you need, you can contact the Cozy parts department by using the link below
http://www.cozyparts.com/Lennox-Parts/locator_form.aspx

Go to Top of Page

tgrill

3 Posts

Posted - 06/19/2008 :  10:59:16 PM  Show Profile  Reply with Quote
While testing the relay I noticed that there was continuity between the two wires in the AC compressor control cable (i.e. the wire pair connected to the AC compressor contactor). I did this test with the wire ends removed from the low voltage terminal strip in the furnance (i.e. eliminating any furnace connections). Is this normal or could there be a short in this cable that could have caused the transformer to fry?
Go to Top of Page

Cozy.Support

5895 Posts

Posted - 06/20/2008 :  11:48:11 AM  Show Profile  Reply with Quote
If you are sure than you have both ends of the thermostat cable disconnected, you should not measure any continuity between the wires.



Cozy.Support does not provide a diagnosis for users of this forum. We do, however, try to provide information that will help servicers arrive at their own diagnosis.

Once you know what part you need, you can contact the Cozy parts department by using the link below
http://www.cozyparts.com/Lennox-Parts/locator_form.aspx

Go to Top of Page

tgrill

3 Posts

Posted - 06/20/2008 :  4:15:44 PM  Show Profile  Reply with Quote
Just to be clear, the cable I'm testing is a single pair wire that terminates on the same low voltage terminal strip as the thermostat on one end and the AC compressor contactor on the other end. When I disconnect the wire pair from the terminal strip end only(i.e. eliminating any contact with the thermostat, leaving the connection to the AC compressor contatctor in place) there is continuity between the two open wires. Just to confirm, are you saying this should not be the case?
Go to Top of Page

Cozy.Support

5895 Posts

Posted - 06/20/2008 :  4:24:49 PM  Show Profile  Reply with Quote
If you you leave the contactor coil connected at one end, and measure the resistance with a VOM between the two conductors at the other end of the thermostat wire, you will get continuity, but it should not be zero ohms. The contactor coil will have resistance.



Cozy.Support does not provide a diagnosis for users of this forum. We do, however, try to provide information that will help servicers arrive at their own diagnosis.

Once you know what part you need, you can contact the Cozy parts department by using the link below
http://www.cozyparts.com/Lennox-Parts/locator_form.aspx

Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
Lennox HVAC Owners and Servicers Community Forum © 2002-2015 CozyParts.com, Inc Go To Top Of Page
This page was generated in 0.07 seconds. Snitz Forums 2000

Please Choose Your Destination

Never Forget to Change Your Filter Again!
Get Your
FREE
Reminder
Account
We Can Send You an
Email Reminder!
Lennox

CozyParts.com, Inc. is an
Independent Lennox Dealer

Facebook Contact Google+