Inside Blower motor keeps running

crawlerchris · 12-05-2009, 08:39 PM

Ok,
I have been digging at this problem for a little while on the unit. The inside (evaporator) fan is running all the time. A background of the trouble started a few months ago when the blower motor wiring shorted via rubbing against a lug on a "starting aid" coil. The short caused the blower motor to melt the coil insulation off and go to a dead grounded state. Replaced the blower motor with a new unit and repaired damage from shorting lug (replaced wire terminal that was arc damaged). After firing up the unit post repair, the blower motor turned on and has yet to shut down. I figured perhaps the blower motor relay had fused the contacts and replaced it. That did not solve the trouble so I tested the 24v transformer and one leg seems to be weak so I tossed a transformer at it, figuring I'd waste my money doing so. Well, that did not work so today I started testing again and found one wire energized that should not be.

The unit is a package unit, Goodman PHJ036-18 (which is hard to find info for) but I do have the internal wiring diagram but it is on little use. The blower relay has 5 lugs on it, two are for the 24v coil that actuates the relay. The others are labeled 1,2,and 3. Part number for the relay is B13707-38 . Lug #1 goes to the blower motor, lug #3 is on of the lines/legs of the 240v service, lug #2 heads off to unknown land inside the package unit. #2 is where my troubles are as it is staying hot. When #2 is removed from the relay, the fan operates as it should with it staying off unless you turn the thermostat from "auto" to "on".

My trouble is the wiring diagram does not show where the #2 wire heads to/what it runs off of and or runs. I'm assuming it is possibly hooked to the heater coils and commands the fan to run when the heater electric coils are on. Now, these coils were never wired in on the unit because it's florida and the unit is a heat pump (never needed the electric heater coils to run). The diagram shows the #2 (red) wire going to a 6 pin plug which I can see inside the panel but the diagram does not show what the other side of the 6 pin plug connects with. I don't know if there is a seperate wiring diagram that I have not seen.

If anyone knows what the wire that is hooked to #2 (red wire) runs/connects to, it would be a great help. I plan on popping the top off in the next couple days to see where it's connected at. I assume somewhere there is a relay that fused shut during the short.

crawlerchris · 12-19-2009, 09:01 PM

Ok,
For future info for other with possibly the same problem.
I did some troubleshooting and found the wire in question hooked to another blower relay that was down inside the unit. The unit had a seperate box that contains the electric heating elements for emergency heat. It contained another blower motor relay that had shorted closed, causing the fan to run all the time. I simply disconnected the feed wire to the relay and covered it with heat shrink tubing. My emergency heat is not connected, it needs wires from the contactor to the breaker in the electric heat strip box to function. So, instead of buying another new relay, I just disconnected the only hot wire that was running to the "box". Funny enough, the hot wire was on a double spade that attaches to the blower relay that I had replaced.
Removed the wire from the relay terminal and slipped heatshrink over the connector, problem fixed. I spent $35 buying parts I did not need so it does not hurt too bad, though I'm 99% sure the blower relay I replaced had failed after post removal testing showed it had issues.