L70F Volvo loader. Started going crazy with engine RPMs. Screams wide open then idle then up and down, non stop. The Volvo guy, been doing stuff for us for years. Checked the codes, replaced the peddle. No change. They have been frigging with it for 2 weeks off and on. Only does it cold. Like the cab, not the engine. If the machine is parked inside a warm shop overnight, works fine. First time it happened, he put the new part on, worked fine. They put it outside, it sat for a couple days. I went to go plow snow with it, and it went crazy again.
So there's the fix, park it in the shop beside a cosy fire. It'll show it's gratitude the next day. But how will it deal with a very hot summer? Maybe you'll need a fridge full of cold beers.
Does the machine have 3rd function with hold function and hand throttle ? If not, I would pull the RS glove box and floor covering. Trace the harness from the back panel along the floor towards the dash. The harness is not properly insulated , water from the air conditioner puddles and invades splices. This can result in shorts , opens heavy corrosion and worse corrupt 5v reference feeds.
It has the 3rd valve, but no hand throttle. Was at the shop this morning. They are waiting on a new harness. I guess it was ordered on Tuesday. It looks ok, but he stripped off a section, and it was pretty green. Not sure how much it is, the peddle was almost 2 grand.
The harness mentioned?
Yes, I assume so. They had ordered it before I had posted the question, but I think so. He was not there, but one of our own mechanics was telling me