LITTR

If you are talking about the air solenoid for a Horton fan, it is located on the firewall. You can just follow the air line and it will lead you to it.

Found loose pin going into ACM. It looks like when you plugged harness in the pin was getting pushed back and not making good contact. Repaired pin and the truck has running good. No ACM codes.

Truck has had intermittent loss of directionals over the last few months. Driver states he shuts truck off and then turn back on and the directionals work again. The other day they completely stopped working. I checked power, swapped out directional switch with one I had on the shelf, checked all connections, and still nothing. I did find a drop in voltage (about 1 volt) coming out of electronic flasher. I did not think this would make a difference. What I found to be weird is that with the power disconnected from flasher, if I power the left or the right at the switch harness with my probe the blinker will start working (how is it blinking without the flasher?). Plug the harness back in and nothing. In the end, I reconnected everything with the original switch, sent direct battery power with my probe to the load side of the flasher and everything works. I took my probe off and the blinkers now continue to work, although there is a distinct difference in flash pattern from when I had battery power connected. Can anyone make sense out of this?

Truck is shutting down intermittently. Using tech tool, the truck is coding U010000, U02A200, U114600. Terminals on ACM appear clean. Have not found any break in wiring as of yet. Going to perform a wiggle test. Just wondering if anyone else has experienced something similar.

Update: I replaced the camshaft, bearings, and all hardware for bearing caps and rocker assembly. Noticed a big difference as soon as I started the engine. Just took the truck for a test drive and it is running excellent; no knock! So, the knock that I was hearing was a fuel knock from the #3 injector due to worn cam lobe.

Thanks for the input. I am very familiar with the idler issue on these. I have already had this motor apart and the idler gear has been redone. I am going to replace the cam and bearings. I will post how I make out.

Driver pulled in with a knocking sound coming from engine. Hard to tell if it was lower end or not. Pulled the pan and found metal fragments. Checked #1, #3, #5 rod bearings; all good. Checked main bearing; all good. Looked for any damage to cylinder walls; all good. Pulled P/S pump to check gears and found chipped tooth that matched some of the fragments in pan. Replaced fuel/P/S assembly. Also replaced oil pump while I was there. Moved to the top end and found damaged cam lobe on #3 injector. My question is: can this be the cause of the knock? It sounded to me like a wrist pin or fuel knock. Was wondering if anybody has gone through this before.