The AC in my sons 2004 Eclipse was just not reliable. Came on, wouldn't come on. Gases perfect. Compressor clutch fine. Relays good. What the $#@ was wrong with it?
Turns out this car has an extra controller module inside, on top of the fan box system, called a "compressor clutch controller" Black, about 4 inches square, it determines IF the compressor clutch is allowed to engage. It has a flying 2 lead thermistor that snakes its way to just under the AC evaporator at the center of the dash at the very bottom where the water collects from the evaporator then spills inside the car (another story) The value of this thermistor at normal temps is documented NOWHERE. It should be about 1K+. Mine was 44K which told the module that the vent system was so cold, why bother turning on the clutch?
New (ok old one from ebay) module $20 came with thermistor & long lead. Easy to install. Fixed it right up. This solution was not mentioned on the web so perhaps it is rare. Just recently, this has been my luck.
Thursday, August 15, 2019
Tuesday, August 13, 2019
How to find buried Sprinkler Valves when you have no clue.
Our grass was dying. Something had happened to the lawn sprinkler system - nothing coming out at all.
What to do? Call someone to come fix it = $100-$400. Unlikely for this engineer.
From the main panel, I energized each "zone" of the pop-up sprinklers. Nothing. I was getting the 24V AC on the lines going out and each valve measured about 47ohms so I knew they were at least there.
As an idiot, I did NOT make a system map of the valves and lines when they were installing this irrigation system, something which now came back to bite me.
The panel had wires going to all the zones including one labelled "MV" I guessed that was a "Master Valve" and sure enough, it came on at the same time as each individual zone. Since no zones at all worked - I focused on the Main Valve. OK, WHERE IS IT? No idea at all.
I tried a wire finder to track the underground wires. Too deep.
I saw a product on the internet that turned the valves on & off rapidly making a noise you could hear...bingo! Did I want to wait until I could get one sent to me? No!
How hard would it be to cycle an AC valve 10 times a second? I grabbed a solid state relay that was lying about and connected it to my frequency generator. Connecting this setup in series with my master valve and sure enough, we found it.
The valve wasn't making much noise but when manually opened, all the zones started to work.
Changing a valve is not hard. Backbreaking yes (Texas soil is like concrete where I am)
So $15 later I am ready to re-install. Wish me luck.
What to do? Call someone to come fix it = $100-$400. Unlikely for this engineer.
From the main panel, I energized each "zone" of the pop-up sprinklers. Nothing. I was getting the 24V AC on the lines going out and each valve measured about 47ohms so I knew they were at least there.
As an idiot, I did NOT make a system map of the valves and lines when they were installing this irrigation system, something which now came back to bite me.
The panel had wires going to all the zones including one labelled "MV" I guessed that was a "Master Valve" and sure enough, it came on at the same time as each individual zone. Since no zones at all worked - I focused on the Main Valve. OK, WHERE IS IT? No idea at all.
I tried a wire finder to track the underground wires. Too deep.
I saw a product on the internet that turned the valves on & off rapidly making a noise you could hear...bingo! Did I want to wait until I could get one sent to me? No!
How hard would it be to cycle an AC valve 10 times a second? I grabbed a solid state relay that was lying about and connected it to my frequency generator. Connecting this setup in series with my master valve and sure enough, we found it.
The valve wasn't making much noise but when manually opened, all the zones started to work.
Changing a valve is not hard. Backbreaking yes (Texas soil is like concrete where I am)
So $15 later I am ready to re-install. Wish me luck.
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