Measuring voltage on tach wire

I am installing a remote starter on a 00 mazda 626 (4 cyl.) The literature says to use a red or green wire on the coil for a tach wire (for a 4 cyl.) I found those wires . My question is can I measure this first using a mutimeter before using? If so what should I get for a reading? I just want to be sure before hooking it up to the remote.

put the multimeter to AC and should be readin from 1-6voltageHouston,TX

"The two most common elements in the universe are H+ and stupidity" (Ellison).

I was afraid someone would say that because it may mean i do not have the right wires. I dont see how they could be the wrong ones since they are the only red or green wires i see going to the coil. I tried AC and got nothing. I only got 12 volts DC. I tried both an anaolog and Digital meter.

You also have to place the RED lead on 12 volts and the BLACK lead to the taregt wire. The voltage should read between 1 - 6 volts.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

Velocity Motors wrote: You also have to place the RED lead on 12 volts and the BLACK lead to the taregt wire. The voltage should read between 1 - 6 volts.

ummm...no.  Being AC voltage, why would you place the red lead on +12V???  Put the black lead on solid chassis ground, and probe with the red lead set to measure AC volts.  THE CAR HAS TO BE RUNNING to see it.  Its the wire that reads AC voltage when running, and goes to zero when not.  Also, voltage will increase with RPM...

Perhaps your method applies to a specific vehicle Velocity?  I've never ever heard of that..

b

i put the neg lead on the positive battery post and probe with the pos lead of the meter on AC.  just grab the non common wire at the injectors if you can get to them.

Here is the method for testing a tach wire that has never ever failed me: 1.Strip back the target wire 2.Set your digital multimeter to AC voltage 3.Take the black lead of your meter and put it to the positive terminal of the battery. 4.Take the red lead of your meter and probe the target wire. 5.Start the engine. Your meter should show anywhere from 1 to 3 volts at idle speed. 6.If your meter leads will reach, take the meter inside the vehicle and rev the engine SLIGHTLY. If not, do it manually at the throttle body under the hood. The voltage should increase, however it should go no higher than 8 volts. If the voltage does not increase when the engine revs or if it goes above 8 volts, find a different wire or run the autostarter tachless. This method may seem a little bit excessive or different than what most people do, but like I said, it has never failed me yet.

"Perhaps your method applies to a specific vehicle Velocity? I've never ever heard of that.." You can see just from the replies in this thread that either method works..I put my black lead to ground as you do and red led to the wire for testing either tach or vss wires. For tach it should sit around 1 - 3 volts and rise as your rev the engine. For VSS is usually sits close to zero and will go up to about a 1 volt + with the car rolling. Mike

Well I will give it a try and post back the results.I have done that polarity reversal (red to 12 volt) and black to target wire on DC to test for negative triggers but this one is new to me.

To test a tach wire the best thing i have found is my tach tester! Snap On makes a probe tester for tachs, abs, that type on things it detects electrical pulses in a wire. cost around $83.00