This is my D 90:
It is a 1995 and number 339/500. I love my truck.:)
This week I swapped out the water temperature gauge from the stock I-think-I-might-be-overheating gauge to the a new VDO Vision Series gauge. (BTW, egauges.com rocks!). It also required that replace the water temperature sensor with a VDO 323-417. I ordered several sizes until I finally got the correct one. I found several sizes on threads posted on the D-90 Source forums. My 1995 took an M16x1.5 thread sensor.
It required I pull out the instrument cluster. This was easy, just 4 screws, and it pops right out. Remove the old gauge, replace the electrical connectors with spade connectors that the VDO gauge needs and reassemble the cluster. Be sure the sheathing on your speedometer cable is still slid completely into the back of the speedometer or you will end up with a bouncing speedo! This was a pain to do, but I was able to slide the sheathing toward the speedo while pusing the cluster back in the dash.
Get under the hood and replace the Temperature sensor. It is located just left of the water pump, close to the Thermostat. It has a single green wire running from the stock sensor. Unplug that and get a 19mm deep well socket and loosen it. If you can, park the truck with nose up and this will help alleviate coolant loss. You should take precautions by putting a pan down there to catch the fluid, there will be some loss. Remove the old sensor, and put the new sensor in its place, tighten it down until it is snug. On the wire, replace the spade connector with a ring type connector.
Start up the truck and check for leaks and watch to see that the gauge starts showing temp. Mine runs at right around 180 Degrees F.
The light and readability of this gauge is awesome.
The only drawback is now I am going to have to replace the other gauges.
Difficulty: 1/2 a mantool
