- 2,316
- 917
- 113
- Location
- Fargo ND
Hello guys here is what I have today and I have looked through a whole lot of TMs looking for the answer with no good results! I have an M920 and when I got it the tachograph was working but when the truck was sitting not running the mph indicator would cycle up to about 20 mph on the indicator then would drop back to zero it would do this about every 3 seconds, I pulled the power plug in the back of the tachograph to stop this and it did. I called the company who built the tachograph and when I told them the symptoms the first thing the fellow said is that its missing a signal from the trans. when i told him the year and that it had been rebuilt he knew immediately what it was and told me that the Govt. for about a 1 year period had received a fairly large batch of the wiring harnesses that go from the trans to the tachograph and they only had 3 wires on them and they need 4 wires in this instance AND yes they have a kit that replaces the 3 wire I have for the correct 4 wires I need. OK OK I know this is getting very long winded but there is supposed to be an access panel on the floor of the truck that opens directly on top of the trans over the manifold area, THIS what I can find NO INFO ON WHAT SO EVER in the TMs? Is this true? I wanted to ask you guys if it was before I start tearing into the floor insulation and end up finding no access plate/hatch. My hope is that yes this is true and the wiring I need to change out is located directly under this access point? and I know your thoughts on this "GOOD LUCK"! Let me know your thoughts please and thanks in advance!
Karl
Karl
