DAVEKING40

I Have A 1994 Toyota , Pick Up , 4x4 , 22r , 5 Speed . The Speedometer Will Only Work For A Few Miles When It Is Below 40 Deg. F. As The Truck Warms Up The Speedometer Will Drop Off To " 0 " Mph. If It Is Above 40 Deg. F. The Speedometer Will Saty At " 0 " . I Would Like To Know If Anyone Has Had This Problem , Is The Speedometer Cluster Or The Sensor In The Trans. At Fault ?

Thanks

RedRider

That's weird... I have a 87 4runner that does the complete opposite only in cold weather (sub-40). It will say Im going 40 when im going 20, or 70 when I am going 50. Also, mine is accompanied with a really aggravating buzzing noise. As it warms up, it falls accurate. Dunno, good luck

breknraj

My first guess for both problems would be that your speedometer cables are going out. 4 bangers can usually get replacements at auto parts stores, like NAPA or Autozone, but the V-6 crowd is stuck with dealers or salvage yards.

DAVEKING40

From What I Understand . The 1987 Modles Have A Cable. I Know That My Speeometer Is Electronic. Need To Comferm If It Is A Instrument Cluster Or The Sencer In The Trans. That Has Gone Bad. I Just Dont Want To Change The Wrong Part. Thanks

scope103

I have a 94 4x4 pickup with the 6cyl engine, but it sounds like you have the same transfer case. I had almost the same symptoms (speedo works fine most of the time, then suddenly drops to zero.) In my case it was the sensor bolted into the transfer case; popped it out, put in a new one, and the problem was fixed.

Now for the bad news. The part is $232. (3 yrs ago) (This does not include the drive gear, but the one you have is fine and will easily fit in the new sensor.) No, that's not the bad news. The bad news is that you can't return electrical parts; are you going to take a $232 chance that some stranger diagnosed your problem correctly?

Fortunately (?) the sensor is just an amplified hall-effect sensor, so it has a gnd (grn), +12(blk/grn), and signal(grn/red) connection. The signal connection is just off or on as the gear turns, "about" (but not quite) once per turn of the driveshaft. How do I know this? I have signal generator, and I connected a 12v square-wave into the signal connector, and the speedometer indicated 30mph at 33.7Hz (I could set any speed just by changing the generator frequency.)

If you have a square wave generator (or even an old telephone dial ...) you now have enough information to test. But you probably don't. If I were you, I'd jack up one rear wheel, pull the connector underneath, using the color-codes I gave attach 12v and gnd to the sensor. Then measure the voltage at the signal connector to ground, as someone turns the wheel which turns the driveshaft. (you can do this by yourself; you just need enough wire so you can see the multimeter while you turn the wheel). If you're confident of your connections (the connector is not big, so you'll need tiny alligator clips), and you get no change on the signal wire as you rotate the wheel, you can confidently spend your $232.

Good luck.