Air Cond. problems in my truck
Printed From: Unofficial Allis
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Forum Name: Shops, Barns, Varmints, and Trucks
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=150203
Printed Date: 15 Nov 2024 at 3:56pm
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Topic: Air Cond. problems in my truck
Posted By: JW in MO
Subject: Air Cond. problems in my truck
Date Posted: 06 May 2018 at 8:15pm
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05 Silverado 3500, ran the a/c last weekend and worked just fine, today not so much. Compressor won't kick on, system has plenty of pressure, fuses good, if I manually make the relay contacts the compressor runs. I have 12v to the relay coil but not a ground. I have swapped relays with a known working one and nothing. I have manually jumpered the low and high pressure switch individually but nothing. I noticed a check engine light, diagnostic said low voltage circuit B, cleared the fault, nothing. Is there another pressure switch besides the one on the accumulator tank and on the discharge line? ------------- Maximum use of available resources! |
Replies:
Posted By: Clay
Date Posted: 06 May 2018 at 10:06pm
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Have you put a code reader on the truck? |
Posted By: JW in MO
Date Posted: 07 May 2018 at 7:31pm
That's how I got "I noticed a check engine light, diagnostic said low http://i.viglink.com/?key=d7d7aa5ced1ebc0821effbccab897fa0&insertId=9c17918c70278d0340082a880ede4605&type=H&mid=undefined&exp=60%3ACI1C55A%3A4&libId=jgwxtuid010009ks000DA3bys6mec&loc=http%3A%2F%2Fallischalmers.com%2Fforum%2Fair-cond-problems-in-my-truck_topic150203.html&v=1&out=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000Y2LPAI&ref=http%3A%2F%2Fallischalmers.com%2Fforum%2Fshops-barns-varmints-and-trucks_forum4%26SID%3D110743-b95a3557f8d1ffa4afea8112384259.html&title=Air%20Cond.%20problems%20in%20my%20truck%20-%20AllisChalmers%20Forum&txt=%3Cspan%3Evoltage%20%3C%2Fspan%3E%3Cspan%3Ecircuit%20%3C%2Fspan%3E%3Cspan%3EB%3C%2Fspan%3E" rel="nofollow - ------------- Maximum use of available resources! |
Clay wrote:Posted By: steve(ill)
Date Posted: 07 May 2018 at 7:39pm
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Wendell, I don't claim to know anything about that truck... but on many FORDS there is power to the switch / blower / fan etc... and the dash knob when rotated completes the GROUND CIRCUIT..... Many times people are looking for the switch to supply POWER to a component, when actually it forms the GROUND.......... bad switch or ground wire ?? ------------- Like them all, but love the "B"s. |
Posted By: JW in MO
Date Posted: 07 May 2018 at 8:36pm
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Yeah, that's kinda where I'm at, after rechecking the pressure switches with a test light they don't have voltage so I'm just guessing that they are on the ground circuit since I have 12 volts to the relay coil. ------------- Maximum use of available resources! |
Posted By: Tbone95
Date Posted: 08 May 2018 at 7:55am
| Is the blower working? |
Posted By: JW in MO
Date Posted: 08 May 2018 at 8:05am
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Yes, blower works, snowflake appears when I turn it on. ------------- Maximum use of available resources! |
Posted By: Brian Jasper co. Ia
Date Posted: 08 May 2018 at 8:10am
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It has a trinary switch on the high side. You need to look at the data for the system. Sounds like you have a malfunction like the 5v ref side down or shorted to ground and the ECM is withholding compressor operation. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: JW in MO
Date Posted: 08 May 2018 at 8:37pm
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Well I went out tonight armed with a wiring diagram and a meter, started the truck and the A/C worked just fine. I never moved it or anything since the last episode. Now I know it aint like a sore thumb and just up and healed itself but I am going to be prepared. Only sure way I know to make it happen again is. . . . Hey Maddux, want to go on a road trip? ------------- Maximum use of available resources! |
Posted By: john(MI)
Date Posted: 09 May 2018 at 9:05am
We used to roll down the windows for the AC! ------------- D14, D17, 5020, 612H, CASE 446 |
Posted By: shameless dude
Date Posted: 09 May 2018 at 11:54am
| lol....I was in town the other day and stopped at the gas station, a dude asked me why I had my windows rolled up on such a hot day? told him so the ac cool won't get out! he said (with a funny look on his face) that old truck has a working ac???? told him..yeah don't yers? (he had a pretty new truck) he said his quit the year before and figgered it was done. said he might see if he can gits it fixed. yeah Les and Joe...it was a newer ferd pickup! |