Re: Tech not working
Seeing your problems are all in the Dash area, I too would point to the grounding system.
Is the Dash a single unit or all individual gauges ?
IF, when you're looking for the ground, you find a lot of dirt, corrosion, and just plain bad connections, you might want to consider running new ground wiring. I know you are probably saying NO WAY, but in the long run do a GWRP, "ground wire replacement procedure" (LoL), you will reduce the number of electrical problem you could encounter in the future.
Since you have no info about where you live, or where the Tractor came from, you may, based on weather conditions, run into other electrical problems, so a little proactive electrical work MAY help in the long run, i.e. charging system grounding, and new grounds for the engine, the alternator, and the starter.
Then there is the sending units, are they in good condition, are they rusted, or maybe even have they been replaced and there is too much sealing paste. What condition is the wiring to the sending units ?
OK I'm done, I do things thinking ahead not just in the moment, so take my suggestions with a little more than a grain of salt !