Alternator Tach.. again

[bgilbert]

Ok bought an isspro alternator tach, couldnt get it to work with the wire/eyelet attached to any of the bolts/nuts on the back of the alternator. As directions indicated, the tach reseted to zero once power was sent to it. But no movement at idle or wot. So I took it back to where I bought it, and they sent it to isspro, AND now I have a replacement, but of course, I don't have the wire hooked up correctly cause this tach doesnt work either.



Anyone have a diagram or 'bigger' picture of where they have there alt tach hooked up? Am I missing something a sensor or do I just run the stator wire with eyelet end to a bolt and tighten down ? Thanks, Bill

 

[JLEONARD]

If it a tach that runs off an alternator pulse, then you need to attach the wire to any one of the rectifyer leads that can be found INSIDE the rear cover of the alternator.

That is the kind of Isspro tach that I have. (R85220)

You can call me if you'd like and I will attempt to talk you thru it.

You can use the toll free number 1-800-775-2690 ext 5456 at the prompt. I am here from 6 am to 4 pm eastern time... but the best time to call is before 8 or between 12 and 1.

Jay

 

[REakin]

I tried that when I was installing my tach. My alternator stopped working. Then when I took it off it will try to overcharge when running down the highway, and hardly maintain 10 volts at idle. I allready tried a new voltage regulator.



Sorry to hijack the thread, but it seemed like a good place to ask!

 

[JLEONARD]

REakin, Can't help you on that one. I didn't run into any problems.

Jay

 

[bgilbert]

Update

Thanks alot Jay, I tried calling a few times today but you were busy, went to voicemail. But I tried to remove the damn alternator from the truck, the bottom bolt hole there was like an extension that I couldnt get out, anyways it doesnt matter now, nevermind. I took the black plastic cover off of the back of the alt, down about 8 oclock, there was a white porceln looking thing with two bolts holding it to the alt, and maybe 3 small screws/bolts coming out of it, facing the block. Positioned my tach so I could see it from the engine, and touched my wire eyelet to the top screw/bolt facing the block and I could see the tach was idling near 5-600 rpm, woo hoo. . Bolt everything back up, road test, Only reads up to 2000 rpm WOT???!!! Whats the deal?



Heres some pics, if ya look close down the center, you might see the screw I used ... BTW Thanks again Jay, looks like this can be down with the alternator still on the truck. . Bill

 

[bgilbert]

another

btw ; still a work in progress, need a plastic pillar cover... anybody got one?

 

[JLEONARD]

Bill,

Too bad we didn't connect.

My back alt cover is steel. I found the job very easy by removing the alt and doing the rest on the bench... . I hate working upside down.

You might try adjusting the tach via the little screws in back. I adjusted mine till it read what the engine sounded like..... then checked it with an optical tach.

Hope this helps.

Jay

 

[bgilbert]

It seems to be on the money at idle, but WOT is only showing 2000 rpm? Will adjusting the calibration screw get this corrected? Thanks Bill

 

[dpuckett]

while on the subject of gauge malfunctions

bgilbert-

Have you had any problems with your EV pyro acting up? Mine has something in the lead wire ground, it will jump around over some bumps. I was in a HORRIBLE mood today, and it started acting up, and I just ripped it all out- have to solder the leadwire back together tomorrow. Maybe now I'll get it fixed.



Daniel

 

[bgilbert]

Daniel, nope no problems so far. Maybe since its only been in the truck for about 50 miles it hasnt had the chance to vibrate and rattle all around and get messed up. Works great, (pre-turbo of course) responds like I never wouldnt have believed. Looks like I should have bought a bigger boost gauge, stock engine, and I'm getting 22psi of boost on a 30 psi guage. POD's and pump tweaks will probly warrant a new boost guage purchase. Bill

 

[JLEONARD]

It seems to be on the money at idle, but WOT is only showing 2000 rpm? Will adjusting the calibration screw get this corrected?

It might just correct things.



By the way, once you get it solved, and you have the chance to calibrate it with an optical tachometer, do so at an rpm range of 2000 plus or minus. It's more important to be accurate at normal driving speeds than at idle.



What the marine guys do is calibrate the tach at WOT in neutral... . or "high idle" as it's often called. They say this will stay consistant (unlkess you play with the gov setting) thuout the life of the engine... . will always repeat unless something major os wrong.

That's what the Cummins tech did to my marine Cummins..... engine had barely enough time on it to bleed the air out of the coolant system and make about 150 deg F... then it was time to bury the throttle. Yikes!!

 

[bgilbert]

[It might just correct things. ] Yep, I might have things figured out. Idle was reading like 500 rpm which is way to low, and WOT was only 2000rpm. I started playing with the adjusting screw on the back of the tach and it registered the idle up to about 700, WOT like 3K, so I figured my top end was about 2600, so I held the throttle wide open and set it to 2600. Idle shows about 600 rpm. Now I just need to get somewhere with a optical tach or something and get it dialed in correctly. Cant find my dyno readout, but I remember WOT at 90 mph was around 2600-2700, so I'll leave it at 2600 til I can get to a optical tach. Thanks again Jay and all who have helped. Anyone have any ?'s, I'll be happy to help if I can. Bill

 

[JLEONARD]

Bill,

Glad it worked out... we like happy endings!!

Jay