jerry p, this is larry perkins from louisville ky 15027276903.
would it be possible that you send me any information available on the still 4klb 1989 with diesel mercedes power?
note that the diesel cars are my speciality and i do a complete rebuild on the 4-5-6 clyl diesel,i fi can help just ask.

Hi gert,

I used the wiring diagram from the service manual. Eventually i replaced all elco's from the control circuit board and one cracked resistor. To my surprise the circuit board worked then i found out that the power board was damaged also. All the power transistors were removed and compared. One proofed to be damaged, this one was replace by a equivalent transistor bought at Conrad electronics. This solved the problem.

Send your email address and i will forward the drawings and pictures. By the way if you look carefully at your circuit board you may find components that have changed colour. These parts have been hot for a longer period of time, replace them and you may get lucky. I may take you several hours in the sun before you spot these parts.
Regards,
Gerrit

hi jerry,

do you have found any drawings?
i have the same problem with a diesel truck

Hi gary. The nameplate says TFG 2.5/7019, the service manual says R70-25T. It runs on LPG. You are correct it has a logic and a power board. I have the drawing on the electric wiring from the yellow service manual.
I am looking for the diagrams of the logic and power board and if possible an explanation on the purpose of measuring points on the boards.
Thanks

Hi...I have a bit of experience on these trucks. I take it that it has just 2 PCB,s...a power board & a logic board, also you don,t say if it diesel or gas & what size is IT?

By the way, I do not understand why the manufacturer doesn't release his nearly 20 years old design.

STILL GmbH, come one, put your 20-year-old stuff on the Internet!!