Well, about 2 months ago, I lost A/C. (blower stopped) I scrounged up almost $200 and some old independent A/C guy came out and said my transformer blew. He installed a new one and the system worked.

For 3 days

Then the transformer went out again. I researched and found that it was the standard 120V in, 24V out... I called the guy back to find out that he was dead. Obviously he can't help me any more. I don't have the money to call anyone else, so I am attempting this all myself.

I installed a new transformer that I got from a local HVAC place. (I took the old ones to him to make sure I got the right kind.)

The new one worked for 5 days. Then it went out. No circuit breakers. No burned parts. Just no output voltage on the transformer.

I checked the resistance on the 120v input and it was zero. I got a new transformer to check, and it was 1.5 ohms, I believe. The 24v output was about 15 ohms on the good and bad transformers, so I assumed the problem came from a power surge.

I installed a fuse on the input. Installed another transformer. This one worked for about 15 minutes.. then a heard..

... that clicking sound that you always hear when an A/C unit turns on...
But it happened rapidly.. about 20 times...

Then the transformer started smoking and the fuse popped. I realized that the problem was actually coming back from the 24 volt side.

My main question... is that "click" sound a relay of some kind? It it a circuit board of some kind? I know it wasn't open sparks.. it's the obvious "click" sound that you always hear when any home A/C unit/blower comes on. (The problem was that the blower stopped working.)

Please help. I can't afford an A/C tech anymore.

-Frank

Frank:

Sorry for your troubles. You likely have short on the secondary side.

A 3 amp fuse permanently installed on the secondary saves the transformer. Use the secondary rather than the primary in this case. Energy limiting transformers are even better. You can short them and nothing bad happens.

Troubleshooting is tough, but easy if you know how to proceed.

You take two 12 V automotive lamps in series. The current used by the bulb should be somewhere between 30-40 VA or watts. That means the bulb current should be less than 35/24 amps each.

Now instead of the fuse popping, when there is a short, the lamp will glow.

Find out what modes causes the lamp to glow. Say it's in AC, ut it doesn't light when the fan is set to on.

Likely causes are then the wiring from the furnace to outside, the AC coil or even a short from he coil to the case.

Now you have to selectively disconnect stuff until the light goes out. Easier said then done.

Energy limiting transformers are even better. You can short them and nothing bad happens.
I like these but you sell less transformers that way. LOL

How is it going KISS? Most service folks around here are complaining since the weather has been cooler than normal.

It's going in some direction, don't know which one.

I have a barely functioning laptop. There is dirt behind the glass, like the LCD was replaced with a remanufactured one. Hard drive crash during sent away repair for cloning. Don't know what I can recover from backup. They put the wrong screw in and proke the lid. Mix of polycarbonate and ABS. I did manage to glue it, but know with run of the mill glue.

I'm having issues with a delay-on-break timer for a bath fan. I probably need to order another, It's intermittant.

My headache went through the roof yesterday, five 7-5-500 persocets, 30 mg oxycontin, Two Zomigs (Cerebral blood vessel reducer) and about 4 Fiorinal and some ice packs and 2 mg Attivan over 24 hours. Sent medical records to John's Hopkins.

Ordered toner.

Ordered ground bonding kits for the antenna mast and some SS clamps.

And I don't trust people who are supposed to be trusted.

And then there is the AMHD doorbell thread. Getting a chime and a lighted doorbell to get along.

Dang Nabit you are have some problems. Toss the timer away for the bath fan the farts will not know the difference.

How you ever injest that many pills and still walk and talk is a miricle.

And I don't trust people who are supposed to be trusted.

You got that right. Been there done that. People who are supposed to know really do not know anymore. Last trip to the DR was a fun time. The Doc said what I wanted to do was a bad idea. We got on his computer and went to John Hopkins. After he read the article he said lets try it. LOL He is a DR and he does not know it all.

Yes a chime and a lighted doorbell will work together. I have one that does. LOL

The timer is for moisture, not farts. Damn, I didn't remove it to get the model number. It's an SSAC part. You should see how many boxes I had to move just to get to it. It's exposed, though.

That was an extremely bad day. Can't walk and talk wit Ativan. Put's me to La La Land.

The door bell thread - quite interesting

And I don't trust people who are supposed to be trusted. This one is bad, really bad.

Hopkins has a 20 page migraine questionnaire, that I didn't know about until I sent the info off.

https://www.askmehelpdesk.com/home-safety-security/door-bell-374625.html

The door bell was a crazy thread. My light works for my door bell BUT the light goes off until the chime stops then comes back on. Over the years (35) I have had to replace the bulb a few times but found it was easier just to get the small switch with the bulb included.

Thanks for the response. All other responses after the helpful one were a bit confusing, though. Haha

I will try the energy limiting transformer next with the 2-light setup. I know it could take hours to find, but I've got good electricity-protective gloves and a good audio book to listed to on my iPod.

I'll update in a few days when I have more info.

Take a look at this thread for the lamp trick:

https://www.askmehelpdesk.com/heating-air-conditioning/repeated-furnace-transformer-burns-280435.html