Tachometer wire testing

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=141615
Printed Date: April 25, 2024 at 5:32 PM

Topic: Tachometer wire testing

Posted By: mai42356
Subject: Tachometer wire testing
Date Posted: August 15, 2016 at 6:51 PM

Does anyone know of a good way to test to see if a wire is a valid tach input wire for remote start. I was thinking maybe using an analog meter and using the voltage scale to see if the the needle bounces increasingly as RPMs rise. Anyone have better information of a known good practice?

Replies:

Posted By: lurch228
Date Posted: August 15, 2016 at 6:56 PM

DMM set to ac is the most common way.

Posted By: mai42356
Date Posted: August 15, 2016 at 7:27 PM

Is there a recommended voltage range to use?
Would perhaps an analog meter would be more visually intuitive do you think?

Posted By: lurch228
Date Posted: August 15, 2016 at 7:53 PM

Lowest Ac setting is good enough. No as the frequency will be to high to see the inverse of the AC sine wave only the peak (high).

Posted By: mai42356
Date Posted: August 15, 2016 at 7:58 PM

Thank you.

Posted By: lurch228
Date Posted: August 15, 2016 at 8:17 PM

Your welcome.

Posted By: i am an idiot
Date Posted: August 15, 2016 at 8:19 PM

Depending on the meter you need to try it on AC and DC volts. The correct wire will show an increase in voltage when you rev the engine.

It is actually a pulsating DC voltage. Some meters will read it as AC and others will read it as DC. Once you figure out which one works on your meter it will be the same vehicle to vehicle.

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