Nordyne MGBA-070-ABFC-01

[love2huntducks]

I have been having problems with my outside A/C unit not coming on. Called a tech and he had to "rig" it in order to work, He said the transformer keeps blowing. Now the fan stays on constantly and I have to turn on the outside unit and fan via breaker. The gas furnace inside is also not working. Any help would be greatly appreciated.

[Robert]

Hi,

You most likely have a low voltage circuit dead short. Get a reputable hvac tech to find it and repair it, not rigged by a tech wannabe.

What all did he rig ?


Thanks,
Robert

[love2huntducks]

Thank you Robert,

He rigged the fan where it would run constantly and where I could turn the unit on by the breaker. He said he needed to rewire the outside unit, but the wiring diagram on the unit was wore off. He told me he needed the wiring diagram in order to fix it!?!? The tstat does nothing. I did not discover the heater issue until a month later. Could the two be linked?

Thanks again

[Robert]

What breaker are you turning a/c on at ? Inside the home service panel, the power pole or wall disconnect at the a/c condensing unit /


Yes, most likely furnace is not working due to same or not working due to his incompetence .

He needs some schooling if he must have a wiring diagram to wire the condensing unit.


Thanks,
Robert

[love2huntducks]

The breaker inside the home service panel. It was a few young guys but I assumed they had to be certified......evidently they are "in training"

[Robert]

Hi,

The problem with that is they are using your units as the testing equipment and guinea pigs for their training.

He must have jumpered the furnace fan relay and the outside condenser contactor.

You can start at the transformer, place a 3A fuse in load side power wire or install a L'il Popper breaker.

Finger trace ALL low voltage wires or test to ground for voltage and test for continuity.

If all wires are ok:

Then jump one component at a time and turn on unit. Do this for heat, then cooling. If the fuse or breaker pops, replace or reset, jump next component and try again.

When it does not pop, problem is the jumpered component.

It will be a wire or component problem, either shorted to ground or a shorted coil.


There are several ways and several helpful tools of trade to find these.

Some are easy and some are very hard, but all can be located.


The a/c problem is easiest, very little wire and few components.

Probably a chewed into wire to unit or the contactor coil shorted out for most common.



Thanks,
Robert