My tachomiter and spedomiter goes on and off randomly

The speed sensor in the transmission may not work without the computer being connected in the circuit.

ABS light needs new hub bearing ,may need to adj. low idle bring a litle higher .

Hello
The engine and automatic transmission in this vehicles drive train are fully electronically controlled by a computer called the PCM (Power Train Control Module). Whenever a problem like this occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM

either the cable is not hooked up or not hooked up right, or cable is broken.

sounds like vacumm problem,could be bad modulator valve for ******,have control sylinoid for egr checked,is it still showing egr problem?

sound's like a bad speed senser your spedomiter it electricly driving by this senser on the tranny somtime's it;s in the tranny, but i'm not shure?

if you drove it too far too fast in 4 wheel low. you could have done some serious damage to the trani. i have the same truck in a 1998 and the tachomiter goes nuts at 15 mph in 4 low. it was never meant to drive for any distance in 4 low. if your lucky. when your rearend went it didn't take out your drive shaft. if your not lucky. your drive shaft took some punishment and in turn damaged the trani.

dealer only think you may need a new BSI unit ? or a new dash unit ? the later is most likely as its a mini computer behind that dash

what is a "spedomiter", some kind of a dash part?

their is a battery on the back of the insterment cluster that may be bad if not it may need a speed sensor on the tranz.