isspro harness 8912-92

[BradG]

hi just bought used 8503 tach and looking at harness, wondering if anyone knew what it contained. don't want to spend 50 dollars if its just wiring with a diode,resistor or something else i could make myself.

 

[Greenleaf]

Sure makes it easy. For 50. 00 I'd get one. Time is money.



The harness contains a diode and several foot of four/five wires w/terminals.



IF youcall ISSPRO, they will be happy to tell you what the diode number is, that way you can get one from Radio Shack and spend 1/3 the money. Not.

 

[Bob Beauchaine]

Try their web site at www.isspro.com if I remember correctly they have a good pic. and description on that web site.



Bob

 

[BPaulsen]

Harness cost $22 bucks from Piers and you NEED the filter mounted in it for the 3" tach and the standard 2-1/16" tach.



You DO NOT NEED it for the EVA series tach, as it won't work with the filter. The harness has basically 5 wires (of which you need only 4), nicely wrapped with gray tubing. Yes, you can make it for $5 yourself, but what's your time worth?

 

[AKimmel]

Harness cost $22 bucks from Piers and you NEED the filter mounted in it for the 3" tach and the standard 2-1/16" tach.



You DO NOT NEED it for the EVA series tach, as it won't work with the filter. The harness has basically 5 wires (of which you need only 4), nicely wrapped with gray tubing. Yes, you can make it for $5 yourself, but what's your time worth?

I have the standard 2 1/16" Tach in my truck and it would not work with the filter hooked up. I wished now I wouldn't have wasted my money on it. I called Isspro when I was having problems, and he's the one that told me to bypass the filter.

 

[Greenleaf]

I have installed several ISSPRO tachs. This is the way it is guys... .



The EV series 5503 tach, for example, will require the 3 3/8 inch gauge instructions. This will by-pass the filter.



Remove the damper from the back of the 5503 tach and connect direct to the back of said gauge.



If your installing the flat face gauge, like the R8503 for example, there is no damper on the back of gauge and you must use the filter.

 

[AKimmel]

My truck must be a freak of nature then, because I have the flat faced R8503, and it didn't work at all with the signal going through the filter. I even sent the guage and harness back to Isspro to have them tested, because I figured something must be defective after reading how everyone else installed theirs on here. They said all was normal, and that it must be my truck. Oh well, it works now, but without the filter.

 

[Greenleaf]

Sometimes you'll find a situation like that. Generally it when a freind asks if I can install a gauge on a Saturday morning... ... ... and I have plans for that afternoon. Come that evening, I'm still working on the install and the guy had to call his wife to pick him up cuz his truck is apart.

 

[BPaulsen]

There you have it. Trucks are people too!



Buy the installation kit. Hook up the white wire (with the filter). If it works, okay, if not hook up the yellow one (without it) and it should work. Any more doubts that spending $22 for the kit makes a lot of sense?

 

[cerberusiam]

My truck must be a freak of nature then, because I have the flat faced R8503, and it didn't work at all with the signal going through the filter. I even sent the guage and harness back to Isspro to have them tested, because I figured something must be defective after reading how everyone else installed theirs on here. They said all was normal, and that it must be my truck. Oh well, it works now, but without the filter.

Went thru the same thing. Didn't work with the filter and the vendor swore it would. Finally called ISSPRO and talked to the tech guys and removed the filter to make it work.



Their response: "The EV series does not generally need the filter as its construction will work quite well without it. No harm to remove the filter and run it that way. "



Depends on how much noise is in the wiring harness and that is probably dependent on how much hacking and accessories have added.

 

[BradG]

thanks i ordered wiring kit and a governor spring from pdr for $15 less than from the isspro sight.

 

[MMeier]

So, on the 4 way connector under the dash, which terminal do I use for the tach signal?

 

[dpuckett]

So, on the 4 way connector under the dash, which terminal do I use for the tach signal?

the grey wire.



Grey: signal from crank sensor

Black (outer): ground

Orange: dimmer circuit

Black (near center): 12V hot (ignition?)



ISSPRO tach wiring (as best I remember, flat faced):

White: Ground

Black: signal

Red: 12V





Hope this clears us some confusion



Daniel

 

[MMeier]

Thanks Daniel!

 

[Leper]

Found the thread I was looking for.