tach input signal

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=43527
Printed Date: July 15, 2025 at 8:00 AM

Topic: tach input signal

Posted By: gasflame
Subject: tach input signal
Date Posted: November 21, 2004 at 11:08 PM

Im installing a Audiovox 786 unit in a 2005 Chevy Express van with 6L engine. I called tech support at AV and inquired about the input signal. I was told that I could use one of the eight coils. Each coil has 4 wires 3 common to each and one diffrent I tied to the diffrent one at the PCM unit. The unit will not learn the tach rate. Can I use the tach signal from the PCM unit or do I have to use muti coils to get the proper signal. The manual shows that the input should be neg. I placed my Fluke on the coil wire but get very little signal change. Any suggestions?

Replies:

Posted By: jaurora
Date Posted: November 22, 2004 at 7:19 AM

Listen to BOBK, With the meter set to ac volts you should see any wher from 0-5 volst on the meter. As the higher the rpm level the higher the voltage.

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MECP certified (If it really means anything)
Jeremy

Posted By: gasflame
Date Posted: November 22, 2004 at 9:28 AM

I did check it with an AC reading .3 to .9 volts as you increase the throtle

Posted By: gasflame
Date Posted: November 22, 2004 at 9:29 AM

I did check it with an AC reading .3 to .9 volts as you increase the

Posted By: gasflame
Date Posted: November 22, 2004 at 9:29 AM

I did check it with an AC reading .3 to .9 volts as you increase the engine

Posted By: gasflame
Date Posted: November 22, 2004 at 9:30 AM

sorry about the multi posts I dont know what happened

Posted By: jaurora
Date Posted: November 22, 2004 at 9:55 AM

Thats your wire.

With the prestge alarms/ starters when the install is finished you must program the tach rate or it will not work.

-------------
MECP certified (If it really means anything)
Jeremy