× Auto Repair Pros Member Benefits TechHelp Knowledge Base Forums Resources My iATN Marketplace Chat Pricing About Us Join Industry Sponsors Video Members Only Repair Shops Auto Pro Careers Auto Pro Reviews
Join Now
International Automotive Technicians Network

Automotive HD/Fleet Forum

Professional automotive forum for discussion of heavy-duty trucks, buses and other on- and off-road equipment, and maintenance of automotive fleet vehicles. Discussion topics include fuels and lubricants, hydraulics, performance, on-board diagnostics, powertrain, power distribution, anti-lock braking and stability control systems, and best practices as they relate to heavy duty and fleet maintenance. This forum is for experienced automotive repair professionals only, membership required.

Continue to the description of our next automotive discussion forum, the HVAC Forum.

Recent Automotive Discussions in the Automotive HD/Fleet Forum

starter engages on it's own
12/04/2025 in the HD/Fleet Forum
[Electrical: 01 GMC C6500 Topkick C6H042 7.2L] Dear sirs, I need your help with sending me a wiring diagram for the starter circuit on this truck. It has a 3116 Cat engine w/a M.T.. Prod.date is 09/00 and I am not sure what mods have been done. The truck...
2013 Ford E450 leaf spring R&R
12/01/2025 in the HD/Fleet Forum
Can't seem to figure out how to reinstall the leaf spring. It has some sort of goofy rear shackle, with a long spring box/bracket that faces forward with a bolt and spacer underneath the spring pack. In the rear, there is some sort of dual rubber blocks t...
K-Line Diag on 24v Modules
11/25/2025 in the HD/Fleet Forum
[Electrical: 14 Kenworth K370 6.7L] Have this K370 Euro 5 vehicle, truck will not start, ground from VIC3-L drops out to start relay when attempting to crank. Try scanning the truck with Davie4 and no come to any K-line modules the cluster and abs module...
No Crank
11/25/2025 in the HD/Fleet Forum
[Electrical: 16 Blue Bird All American FE AAC2810-3006 6.7L] Have this blue bird bus, truck would run and drive by jumping the starter. Ground signal was coming from key switch into the body module but nothing out. Disconnected the module load tested pow...
Rv trans stuck in service mode
11/25/2025 in the HD/Fleet Forum
One of my buddies parked his 1993 turbo diesel RV with an Allison transmission. Apparently there's a button on the shifter that puts the transmission into a diagnostics or service mode. Well after owning it for ten years he decided he wanted to push that ...

Automotive Sponsored Discussion Forums