Truck listed above is an 1500 HD.
About 8 weeks ago I started having trouble with my truck starting. The starter wouldn't crank intermittently. I thought it was the key ignition switch, because it is tricky to turn back into axillary. But it turns out it was just the starter. I replaced the starter about 6 weeks ago and around that same time I noticed my A/C wasn't working. The A/C light on the dash is illuminated showing A/C on. If the Freon is low it will just flash a few times and then stay off. But it isn't doing that now it just stays on. But I tried to put more in, but it didn't take very much. I may have over pressured it.. When I depress the A/C button I hear what sounds like a damper changing position, but the blowing air isn't being cooled. I bridged the low pressure switch, but the clutch didn't engage. I checked the coil and it was open. Clutch coil failed. I couldn't find a new coil so I got one from the auto wrecker. I bench tested the clutch and it works. I tested the clutch again after install by applying 12 volts. A/C clutch works great. I bridge the terminals at the A/C relay and clutch engages. Bad thing is I tested the clutch with the engine running and had the clutch engaged for a minute or 2. It still didn't blow cold. I swapped the AC relay with the horn. Both relays good. 10 amp fuse is good and has 12 volts there. I can't find any fuses under the hood nor under the dash in the cab that are blown. I also bridge the high pressure switch, but and I think it is reverse acting. I ordered a scanner of Ebay that is supposed to do all diagnosing for GMC Sierras. Foxwell NT510 Elite Obd2 Car Code Reader Vehicle Diagnostic Scan Tool All Function Scanner for Buick/Chevrolet/Cadillac/GMC Reset with EPB SAS ABS Oil EPB. It is supposed to arrive today. October 8 2020. I can't find a wiring diagram for my vehicle, which makes it difficult to check point to point/ end to end of wires. I unplugged the computer climate control in the dash and plugged it back in again, but no change. My fear is maybe I broke a wire or connection when doing the starter or damaged the A/C system when trying to add Freon.
Please help.
Jeff
About 8 weeks ago I started having trouble with my truck starting. The starter wouldn't crank intermittently. I thought it was the key ignition switch, because it is tricky to turn back into axillary. But it turns out it was just the starter. I replaced the starter about 6 weeks ago and around that same time I noticed my A/C wasn't working. The A/C light on the dash is illuminated showing A/C on. If the Freon is low it will just flash a few times and then stay off. But it isn't doing that now it just stays on. But I tried to put more in, but it didn't take very much. I may have over pressured it.. When I depress the A/C button I hear what sounds like a damper changing position, but the blowing air isn't being cooled. I bridged the low pressure switch, but the clutch didn't engage. I checked the coil and it was open. Clutch coil failed. I couldn't find a new coil so I got one from the auto wrecker. I bench tested the clutch and it works. I tested the clutch again after install by applying 12 volts. A/C clutch works great. I bridge the terminals at the A/C relay and clutch engages. Bad thing is I tested the clutch with the engine running and had the clutch engaged for a minute or 2. It still didn't blow cold. I swapped the AC relay with the horn. Both relays good. 10 amp fuse is good and has 12 volts there. I can't find any fuses under the hood nor under the dash in the cab that are blown. I also bridge the high pressure switch, but and I think it is reverse acting. I ordered a scanner of Ebay that is supposed to do all diagnosing for GMC Sierras. Foxwell NT510 Elite Obd2 Car Code Reader Vehicle Diagnostic Scan Tool All Function Scanner for Buick/Chevrolet/Cadillac/GMC Reset with EPB SAS ABS Oil EPB. It is supposed to arrive today. October 8 2020. I can't find a wiring diagram for my vehicle, which makes it difficult to check point to point/ end to end of wires. I unplugged the computer climate control in the dash and plugged it back in again, but no change. My fear is maybe I broke a wire or connection when doing the starter or damaged the A/C system when trying to add Freon.
Please help.
Jeff
Oct 8, 2020 at 9:13 AM
