Goodman ARUF - Scratching my head?

[Dr Love]

Ok, never encountered this before. We installed an ARUF Air Handler w/ 10-kw heat strip kit.... Quadruple checked everything, thermostat connections, wiring, etc.......

When the breaker is turned on, blower motor runs continuously..... pulled thermostat, blower still runs.... Pulled "G" wire from board, blower still runs....... I originally thought maybe stuck sequencer, NOPE! Checked for voltage across sequencer and heat strips, nothing..... I could find nothing that's "calling" for the blower to operate......

Here's the strange part.... I pull the purple wire from the normally closed side of blower relay, and the blower stops immediately.........

Maybe a stuck fan relay? ........

[Rubio480]

Possibly fan relay, seen this in a few goodmans and Coleman's


We all make choices, but in the end our choices make us.

[pony]

bad board will be my first guess!

[garyed]

Sounds like it's wired wrong. If you can't find anything wrong with your wiring, don't assume the factory wiring is correct. It could be a bad board or relay but less likely. I'd be looking to see why the purple wire has power on it.
It can even be the wires crossed in the molex plug.

[captaincompressor]

Its either wired wrong or the fan board is holding the fan delay on or the relay is stuck. Pull the green and white wires offthe fan board, turn it on and see if the fan runs. Unplug the heat kit and put the little plug back on the harness that has the two red / black wires and give it 230v. See if it runs.

[Dr Love]

Ok, will do.... I'm starting to lean towards the fan board, because if I pull the purple wire, everything works perfectly....... It's the only way the fan will stop running.

[Dr Love]

It can even be the wires crossed in the molex plug.

I even checked that....LOL!

[Dr Love]

Possibly fan relay, seen this in a few goodmans and Coleman's

Recently? Was it in a new installation?

[garyed]

If I'm understanding this right this is a new install where you pulled the purple wire off the NC point of the relay that is on the board to stop the fan. That means the purple wire should go to the heat relay and should only have power if the heat relay is engaged. That leaves something in the heat strip kit. If the heat relay is not bad then possibly an element got banged up during installation and is grounded.

[Dr Love]

Its either wired wrong or the fan board is holding the fan delay on or the relay is stuck. Pull the green and white wires offthe fan board, turn it on and see if the fan runs. Unplug the heat kit and put the little plug back on the harness that has the two red / black wires and give it 230v. See if it runs.

Did this also..... works perfectly without heat strips with the standard 2-wire molex plug

[Dr Love]

If I'm understanding this right this is a new install where you pulled the purple wire off the NC point of the relay that is on the board to stop the fan. That means the purple wire should go to the heat relay and should only have power if the heat relay is engaged. That leaves something in the heat strip kit. If the heat relay is not bad then possibly an element got banged up during installation and is grounded.

I wondered about that, but there was no voltage going through the heat strips.

[captaincompressor]

Did this also..... works perfectly without heat strips with the standard 2-wire molex plug

the heat kit may be wired wrong. it should have a blue common going to each sequencer. there should be a brown or white going to the sequencer low volt input.
I cant remember on goodmans if the sequencer pulls the fan online or not. look for M1 and M2 on the sequencer and see of it leads to the blower some way.

[Dr Love]

the heat kit may be wired wrong. it should have a blue common going to each sequencer. there should be a brown or white going to the sequencer low volt input.
I cant remember on goodmans if the sequencer pulls the fan online or not. look for M1 and M2 on the sequencer and see of it leads to the blower some way.

Blue on one side, white on the other, for 24 volts....... Sequencer does pull the fan online........ When there's a call for electric heat only, W2 closes at thermostat, but "G" doesn't close, so the purple wire is supposed to provide fan operation whenever the heat strips are engaged. It's supposed to be there as "back-up" so the heat strips never operate without the fan......But......

Even though I measured no voltage across the sequencer, I replaced it out of curiosity......Blower still ran continuously

[garyed]

I wondered about that, but there was no voltage going through the heat strips.

Usually one side of the element is always hot but it wouldn't have to be if it was grounded. The purple wire would act as a neutral if it was grounded and complete 120v. circuit to the fan motor when connected to the board. It would make the fan run slower than normal though. If that were the case then something would blow if the heat strips were engaged so I'd do some more checking to be safe. I would check the purple wire to the other hot leg to see what voltage you're getting. It's even possible that L1 and L2 are mixed up at the heat strips and you're getting 240v. feedback through the strips to your purple wire that's causing your motor to run.
I'd love to see an actual picture of the heat strip wiring.

[Dr Love]

I'd love to see an actual picture of the heat strip wiring.

Am I allowed to upload pictures?

[garyed]

I think so but I forgot we're not in the pro section so responses are limited.

[Dr Love]

Yep, it was the fan relay..... it blew

[JBM1000]

I would immediately see if 20 amps is pulling with the new board at the 60 amp breaker and if so then that will take out the new c/board running both cooling and a sequencer bridged post to purple or (Common Side of the 240 volt eventually burning up wiring etc.) *using purple and red in a dark lit attic is APITA* on ARUF's, see it all the time so you have to stare at it wire by wire three times to catch the FUBAR done at the factory or at the heat pack division. I have found that comparing the online schematic to the sticker in unit can be the culprit so go by the online or call technical and get walked through it wire by wire. "It's just going to be that way from now on with any brand out there due to out sourcing and getting rid of people that have technical intuitive brain cells".

[Dr Love]

I would immediately see if 20 amps is pulling with the new board at the 60 amp breaker and if so then that will take out the new c/board running both cooling and a sequencer bridged post to purple or (Common Side of the 240 volt eventually burning up wiring etc.) *using purple and red in a dark lit attic is APITA* on ARUF's, see it all the time so you have to stare at it wire by wire three times to catch the FUBAR done at the factory or at the heat pack division. I have found that comparing the online schematic to the sticker in unit can be the culprit so go by the online or call technical and get walked through it wire by wire. "It's just going to be that way from now on with any brand out there due to out sourcing and getting rid of people that have technical intuitive brain cells".

That's what happened when the purple wire is connected. If I leave it disconnected, it works beautifully,even in emergency heat.

[garyed]

I apologize if i'm wrong but I'm starting to think this is a DIY job so I'm going to bail out of this thread. This is too simple a problem to need this much attention.