RWH was the first company to uncover the issues related to the 400amp quite shortly after ECV trucks were introduced into the market place, since that time, I’ve personally removed 12, I know this because I had 12 spare 200amps and they are now gone.
The 12 removed 400’s are being reused into trucks that have missing Gens or defective gens…that number is dwindling fast.
There are 2 methods that the 400amp got into the truck, either as an MWO at Albany/Yermo or at the factory …the MWO’s are the real culprits, what causes the biggest issue is the rear fan shroud contacting the body harness, it eventually wears away and shorts out whatever it feels like, In one case, it ate up an S3, all 8 glow plugs, shut down the A/C, made the head lights inop….
One issue is the wearing away of the water separator hose, I now replace every water separator hose in ever truck that comes into the shop, as well as reroute so it will never come in contact with any part of the generator.
Being it’s an expensive swap to the 200amp, its best to perform an inspection of the rear fan shroud area for contact of the body harness, if there is in fact contact, inspect the best you can for any damage, attempt to slide a piece of hard rubber in between the shroud and harness To prevent any further contac. The factory and MWO call for a large piece of split loom to cover the body harness to prevent this very thing from happening, unfortunately the split loom was installed incorrectly or is missing all together, again….MWO installs, Reset yards and OEM really dictate the number of trucks that have the issue, if any issue at all.
sooooo, other than just making it a PITA to change your fuel filter or replace a glow plug or even check your oil…the 400 will do what it’s designed to do, it just makes it a bit more time consuming.
Lastly, the smaller fixed pulley will show a higher indicated RPM on the tachometer, if you want to lower the indicated RPM, install the clutch pulley setup and the correct serp belt.
