| [GMCnet] Furnace from hell returns [message #294342] |
Sun, 24 January 2016 20:52  |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
Lance,
When checking voltage be sure to use the furnace ground. The ground side of a dc circuit is just as important as the plus side. Often you will find good power in when you measure from a plus terminal to a good ground, but inadequate power when measured to a weak ground.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
"...................
Message: 3
Date: Fri, 22 Jan 2016 16:25:37 -0700
From: Lance
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Furnace from hell returns
Message-ID:
Content-Type: text/plain; charset="utf-8"
As I said, I checked the voltage at the furnace and all the connections. All good.
--
1974 Palm Beach
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
| Re: [GMCnet] Furnace from hell returns [message #294353 is a reply to message #294342] |
Mon, 25 January 2016 01:23  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
glwgmc wrote on Sun, 24 January 2016 20:52Lance,
When checking voltage be sure to use the furnace ground. The ground side of a dc circuit is just as important as the plus side. Often you will find good power in when you measure from a plus terminal to a good ground, but inadequate power when measured to a weak ground.
Jerry
Jerry Work
I tried to get him to do just that when it was failing. I got a response back that is was 12 to 13 volts and now failing so he could not measure it.
I guess I explained it wrong. Maybe someone else can try to explain it batter.
I was hoping he would say something like it read 12.8 volts between the furnace ground and +12 connections on the furnace before he tried to start it and maybe 10.2 volts while he tried to start / run the furnace. Taking voltage readings while it is running correctly are not much help. We need the readings while it is failing.
If the readings at those points are good and the furnace is failing, then the problem is inside the furnace or the thermostat circuit. If the readings are bad then the problem is in the plus (or minus) 12 volt feed. Also if he is running on the converter then the readings should be in the 13.5 or so range. If he is running on the batteries only then the readings should be in the 12.5 or slightly less range.
I tried to explain this. Someone else might try to word it differently for me.
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: [GMCnet] Furnace from hell returns [message #294358 is a reply to message #294342] |
Mon, 25 January 2016 08:30 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
My furnace has a reset button... very small - on the side. If it has popped out, the furnace will be dead till it's reset. The descriptions are of an intermittent, finding it can be a fun exercise. Uncover the control board, get a schematic, and follow the voltage till it ain't where it oughta be. back up one step and lookit what's in between volts and no volts. If you want to play the odds, connections are the most often culprits, these include solder joints.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
