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How to repair a faulty A/C in less than 30 seconds

JohnnyCarcinogen

Active Member
Joined
Aug 3, 2019
Messages
40
Location
Missouri
Occupation
Trash Monkey
Where I work, we have 2 Cat 836 trash compactors. We have a H model that has about 12k hours, and a K model that we're leasing to eventually break enough to buy. As soon as the city told us the K model was "on the books," we started running that. Since the chief complaint about the H from the operators was the A/C wasn't working, I drug it into the shop, found a faulty compressor, and replaced it.

Fast forward a week or so, and I finally had the time to evacuate and recharge the system, but still hadn't reconnected high and low side switch harnesses. The other guy in the shop has been at our dump for 20 some odd years, and even though I have seniority in position, I've deferred to him because he's be mechanicing there off and on his entire career. Sometimes, the old man likes to pull me off of a job he doesn't think is a priority, telling me "You can finish that later, they don't need it."

Yesterday, I swapped the 836K for the H so Cat could come and do their 500 hr service. Immediately, the operator started complaining about the A/C. I told him that I didn't have A/C in Iraq, and he could drink water for two days while the new compactor was down for a service.

Typical rookie mistake, I ordered a low-pressure switch from Cat today, went down to trash with switch and wrench in hand, and opened the engine access panel. Looked down to see two unhooked harnesses. Plugged them back in, walked up to the cab, and within a minute, the vents were chucking ice cubes.

At least I have a spare switch, now. :)
 

mitch504

Senior Member
Joined
Feb 27, 2010
Messages
5,776
Location
Andrews SC
I had an '86 Chevy C30 service truck, with no A/C, about January the fan quit blowing. I just never got in the mood to pull the whole dash out to change it, or, when I was in the mood I was busy, when I wasn't busy, I wasn't in the mood.

It was about the 3rd or 4th coldest winter I remember here, got down to 12f at night a few times, more cold days than normal. I only had heat and defrost at highway speed. I cussed a lot, (I am a tropical / sub-tropical boy, ya know).

About April, I was checking the oil and looked down by my hand, boy, did I ever cuss myself! Right there, under the hood, is the fan motor! 3 screws! 10 minutes to change it out!

I looked more carefully and boy did the fur fly! it was unplugged
 

JohnnyCarcinogen

Active Member
Joined
Aug 3, 2019
Messages
40
Location
Missouri
Occupation
Trash Monkey
Do you have any idea how or why two harnesses were unplugged ?
I certainly do. The other mechanic pulled me off of that to help install new wheels and cleaner bars on the other 836, and by the time we were done with that, another mission critical piece of equipment went down and it just slipped my mind.
 

DIYDAVE

Senior Member
Joined
Feb 18, 2007
Messages
2,419
Location
MD
Fixed the '94 dodge duckodor, yesterday, on the road. Driving down the highway, made a u-turn, to get breakfast, and all of a sudden , lost dash lights, popped a flashlight on, and all the gauges on the left were at minimum, all the gauges on the right, were maxed out, so I figgered the problem was plumb in da midde of the dash cluster. Taking careful aim, while drivin, punched the top of the dash, with me right meat hook, and PRESTO! the dash was workin again!:D
 

JohnnyCarcinogen

Active Member
Joined
Aug 3, 2019
Messages
40
Location
Missouri
Occupation
Trash Monkey
Fixed the '94 dodge duckodor, yesterday, on the road. Driving down the highway, made a u-turn, to get breakfast, and all of a sudden , lost dash lights, popped a flashlight on, and all the gauges on the left were at minimum, all the gauges on the right, were maxed out, so I figgered the problem was plumb in da midde of the dash cluster. Taking careful aim, while drivin, punched the top of the dash, with me right meat hook, and PRESTO! the dash was workin again!:D
That’s the sort of repair that only a master mechanic could muster!
 
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