Electronics are not my forte. My speedometer has quit working. I have swapped the speed sensor with two other known good speedo sensors, and tested them all, and they all check out as working.

I'm looking at the FSM (page EL-78 for the 95 max) but reading electrical diagrams is not my thing. I need help. What are M58, M50, F105, F102, etc? What is the next step in troubleshooting this?

 

Did you check the little connector that's by the starter, it might just be unplugged?

 

it's plugged in.

 

maybe somthing is busted in the gauge mechanics

 

have you checked your grounds?

 

the ground for the speedo is shared by the fuel gauge, and the fuel gauge works fine, so it's good. it must just be a wiring discontinuity problem. time to start tracing those two wires. i realized after I posted this that the Ms and Fs are male and female connectors.

 

i had the same thing and had to replace the speedo cluster but before that it seemed like there was a lose wire and i would tap on the cluster and fixed it for the moment.

 

Sometimes tightening the screws on the back of the cluster helps. If not, you probably need a new cluster (or speedo).

 

I tap my dash top to get it going again. It seems to rejuvenate above 40mph. So usually, I don't think about it till I get into 5th gear, then I start tapping the dash top if it hasn't already woken up.

I've replaced my sensors, did the continuity check, but nothing. I'm thinking it's the guage, but there's not much I can do besides replace it. If you could take it apart, you could easily roll back the odo, and I'm sure they wouldn't like it if you did that. Good luck and keep posting updates.

Dr J

 

Pull the cluster and redo all the connections on the back,especially the one to the speedo.

 

I know you just had your cluster out to install your I-MFD wideband and SM-Fluid Temp so you might have knocked something loose in the cluster somewhere. Just an idea.

 

I tried the "take out the cluster and tighten every screw" and that worked for several months. I haven't gone back to try it again, I didn't enjoy taking it out. But I think you're onto something here.

Nealoc187: how many miles you got?

Dr J

 

makesure everything is plugged in.Make Sure!!!!

 

Was just a wiring problem - had to be a break/short in the wire somewhere. I ran a new set of wires to it and it works fine now.

 

yeah neal same thing happened to my cluster so i replaced it with another one just to find that it was just the speed sensor unplugged....

 

M denotes connectors belonging to the main (dash) harness and F denotes connectors belonging to the engine control harness. [for future reference]


Good that you got it figured out though.

 

You just ran some continuity checks and found it? Last time I did that, everything was continuous.
Dr J

 

yes. i put the front up on jack stands and started the car and put it in gear. unplugged the harness from the sensor and checked the voltage just to make sure the sensor was outputting the correct voltage, it was. then I checked the same wires behind my gauge cluster and there was no voltage, so I knew it had to just be a break in the circuit somewhere. I just ran two new wires to the speedo from the sensor and problem was solved.