92 300D diesel tach burned up

[ohiomike]

I posted for help several times and got some good tips. Today I pulled the dashpod and took the tachometer out. The red power wire attached to the board was totally burned off its solder point. There were several components soldered to the board that were aslo burned off completey. The solder had melted and the components were stuck to the magnets of the tachometer. This had to be a very hot situation.

Does anyone know why fuses wouldnt blow or what kind of voltage and from where that would cause such heat? These 124 models for their year do not have fender amplifiers so wherever the voltage came from is what i will be looking for and replacing before replacing the tachometer. Any advice would be appreciated.