teamcrossworks

Boy does it take me a long time to do any work on this car...

Brought my car home after having it in storage for the winter and finally looking to fix my speedometer that stopped working after the last time it was stored (about 25miles ago)... pathetic.

Does anyone know how to:

First - test the sending unit
Second - remove it if need of replacing

I was able to get the connector off and the connection points look like they need a cleaning (that would be nice if that was it) but I want to check it if possible before putting the car down.

Thank you.

teamcrossworks

Anybody?

Dan Martinic

When you say "connection points", what are you referring to? One time while working nearby, I accidentally popped the top half of mine off. Didn't look like anything was broken, so I unscrewed the remaining bottom part, cleaned it up, put it back together, and.... ...couldn't get it to work after that. I ended up buying a new one.

The whole thing is supposed to come off as a unit (it unscrews). I do not believe they are meant to be serviceable.

teamcrossworks

Thanks Dan.

I cleaned the connection between the sending unit and the wiring harness (hoping for the easy fix first) but still not working. I wanted to be able to test the unit before purchasing a new one...

Dan Martinic

Oh, I see. Well, you could give it one more try: unscrew the entire unit from the transmission. Be careful, and iirc, there's an obvious flat part to place your tool (I used small sliding pliers). Once in hand, maybe you can spin the inside stick fast enough while watching a connected voltmeter for any sign of life. Perhaps rig a slow drill to turn it?

If you're convinced it's not producing anything of note, carefully separate the top part from the base. You'll see a small circuit board and some contacts. Maybe you'll get lucky and clean those contacts, snap it all back together, and it will work.

Probably not.

If the wiring harness end and wire itself appear good, you can take the plunge and buy a new sending unit. Not the cheapest thing.... I think I paid around $80 USD? When trying to recall actual costs of parts I've replaced, my memory mysteriously fails me lol

931guru

You can bench test the speedo sensor.

You will need 12 vdc, ground, and a means to turning the sender guts (use a drill motor and the white gear under the aluminum bracket). You will also need an oscilloscope to measure the pulsed.

pin 1 - 12vdc
pin 2 - ground
pin 3 - output to speedo

Dan Martinic

In the absence of an oscilloscope, get a little 12v LED from the electronics supply

teamcrossworks

Thank you guys!!!

Really appreciate it. I will let you know how I make out...

teamcrossworks

So I decided to just replace the sending unit and of course it did not fix the problem. Speedometer still does not work.

I had mentioned the boost gauge is not working either and I just thought to try and reset the odometer without success on that...

Could I be missing "power" to the cluster somehow?

Suggestions?

mtnman82

Have you looked at any of Tom M'Guinn's (Amalgamated Tom) speedometer threads/posts? I seem to recall Tom posting some good info. The speedo and boost gauges seem to be related, based on Tom's speedo/boost gauge adjustment box. Maybe Tom will chime in...

teamcrossworks

Tom has chimed in and I certainly appreciate his and all help.

Thx