Both the speedometer, odometer and the fuel gage are inop. Regarding the speedometer, is it electronic or old cable drive? Where do I begin the trouble shooting process. Same question for fuel gage, where do I begin?

Submitted by lebrun1@windst… on Wed, 07/10/2013 - 20:36

Just changed both senders in my 87 xj6, very simple. Make sure fuel is under half a tank and then pull out the tail light assy. through the tail light access hole turn the locking collar and pull out the sending unit . There will only be 2 wires pressed on to the cover. You will probably find that the floats on the sending unit are full of fuel keeping them at the bottom of the tank. I purchased new ones for about 45 dollars.

Submitted by dougdwyer1@com… on Sun, 01/13/2013 - 13:54

Electric speedometer. On principle the relevent connectors should be checked, as well as supply voltage at the back of the speedo, but in the majority of cases the transmission mounted "speedometer transducer" is the culprit. About $100 or so, last time I looked.

Fuel gauge: the system is non-exotic. A sending unit in each tank sends a variable ground to the fuel gauge. Wiring from each sender goes thru the dashboard changeover . The easy test to to turn the key on and ground the sending unit wire for the tank selected. The gauge should swing over the "F". If it does, then everything forward of the sending unit is OK. If it doesn't, there are various possibilities.

Repeat for other side.

Failed sending units are the culprit in most cases.

Post back if more details needed.

Cheers
DD