I had my altenator replaced and now my tachometer has stopped working. Instead of having a three wire alt. I now have a two wire alt. Can this be the problem?
I had a mechanic look for the reason and he came up with a blank and could not offer a suggestion.
I am open to suggestions.

Also my speedometer (electronic) stopped working on my last trip . What should I look for in checking that?

Thanks

quote:

Originally posted by Jim & Barb Rustige:
...my tachometer has stopped working. Instead of having a three wire alt. I now have a two wire alt. Can this be the problem?

Yep, that's it! You have the wrong alternator.

Don't worry, all is not lost.

A pulse is taken off of the "tach" output of the alternator on your original three wire alternator.

It's just a wire connected into one of the three stator windings. That sends out an AC sine wave signal that the tach converts into a usable RPM signal.

One of the few variables you can adjust in the field is the pulley size. A smaller pulley will give you higher RPM signal and better lower RPM charge. So, for anyone who has changed the pulley diameter size to get better lower rpm charging then you have also changed your tach readings.

Give your alternator to an automotive electric store and have them add a stator tap or swap out your alternator for the correct one with a tach feed post.

quote:

Originally posted by Jim & Barb Rustige:
Also my speedometer (electronic) stopped working on my last trip . What should I look for in checking that?

This post might shed some light on your Speedo Problem.

Bill N.Y.

Bill, Thanks for the info on the tach & speedomter. I will be looking into this.

My cruise control also stopped about the same time the speedomter starting acting up. I have been told that the two are connected.

Thats again,

Jim

quote:

Originally posted by Jim & Barb Rustige:
My cruise control also stopped about the same time the speedomter starting acting up. I have been told that the two are connected.

The speedometer and the cruise control are both related. If the magnetic pickup to the speedo doesn't send out a pulse then the cruise can't set. It's like trying to engage your cruise control while parked, that's what the cruise control thinks is happening, it doesn't know that your moving.

My tachometer stopped working too and could not figure out why until I found this in the archives. Had my alternator replaced a few months ago and did not know it had anything to do with the tachometer. Previously, the readings always fluctuated a lot and never seemed to be accurate. But now, I get nothing. You would think mechanics would know about this. What to do now?

Update to my post above... I looked up my alternator on line and was able to locate the "R" post on the back of my alternator. The mechanic connected my tact wire to the B+ post which is why it was not working. I placed it on the "R" post and now the tachometer seems to be working fine.... at least in the idle mode. Have not taken out on a road test yet.