Had to replace my instrument cluster on the 505 SRDT series 2, same old jaeger story with the odometer going ballistic, got lucky at pick a part and got one from a '87 GTD with only 330th showing on the odometer. Should last for a few more years.
The top right hand gauge on the the SRDT showed engine oil temp and was powered by a third sender on the base of the oil filter. On the GTD there was only two senders (no oil temp sender) and the gauge on the instrument cluster now operates more like it indicates oil pressure. I have disconnected the wire to the third sender and the gauge still functions, jumping up to the fourth line on start up.
Did the function of this gauge change between models,