alternator tach install

[bgilbert]

Bought an Isspro 3 3/8" alt tach. My question is to calibrate this tach it says I need to know the alternator poles and pulley ratio's??? I do not know what those are or how to find them. It gives a chart says 'calibration of this alt tach requires that the alternator poles and pulley ratio's be within the ratio's in the chart. '

# of alternator field poles/pulley ratio

8 -- 2. 5 to 5. 4

12 -- 1. 7 to 3. 1

14 -- 1. 5 to 3. 1

16 -- 1. 3 to 2. 7



I hope this chart came out right. The tach has a calibration adjustment on back of tach. 4 wires, one to ignition switched power, got that. one to ground, ok. dash lamp power, ok. Then one to alternator tap (stator). Don't know what this one is??

I should get this part figured out before I get to calibrating the tach to the correct rpm. Thats another story. Thanks Bill

 

[The patriot]

I got the same tach.

You dont have a plug on the alternator for a tach, so you'll have to call Isspro and get the magnetic pickup for the vibration damper.

When I called, the guy on the phone knew exactly what I needed.

I think it was $20. 00 or $30. 00.

I still have to get the time to install mine on the ol 1st gen.

Eric

 

["Mad Max"]

Bill -

My Autometer tach (#2888) also uses the alternator tap and has a small dial-adjuster on the back. I went to a KW service shop and the guys there hooked a neato little hand-held tach that attached to the balancer. FIred up the truck, read the hand-held rpm-o-meter, and set my tach to match. Was pretty cool. At lower rpm's (idle, etc) the rpm sometimes twitches a few rpm, but once on the gas it evens out nice and smooth. I need to get one of those palm tachs.

Anyway, FWIW.

- S

 

[JLEONARD]

Then one to alternator tap (stator). Don't know what this one is??

Bill, I have an Isspro alt tach as well. You will have to remove the alternator from the truck to hook a wire to one of the rectifiers.

Remove the rear cover and you will see several screw terminals. Hook wire with a ring eye or horseshoe terminal to one of these.

This will give the tach a signal. I don't recall where to set the switch, but once it's hooked up, turn the switch while at idle and one should be close.

Then you'll need a hand held optical tach to verify it. I would check it at around 2000 rpm (block of wood,or whatever in the linkage) with the hand held... ... . then make sure the Isspro is there... if not make an adjustment.



Good luck... e-mail me here -- email address removed -- if you have more questions or get stuck.



Jay