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How to measure signal for tachometer?

Posted: January 13th, 2015, 12:04 pm
by sishi
Hello,

my tacho stop working (HEI without resistor) so I buy a used one and replace it. Both are same TAA77-A. Unfortunetely new tacho also don't work. Now I would like to measure the tacho signal from distributor and also from dash board connector to find out where is the problem.
How can I measure tacho signal?
Which conector on distrubutor TOT57171 gives tacho signal?
Which pin on dash connector should give tacho signal?

I have 1997, V6 with LPG.

Kind regards from Slovenia

Re: How to measure signal for tachometer?

Posted: January 14th, 2015, 1:41 am
by MX_Sid
Check out the online manual wiring diagram.

http://www.mx-3.com/manuals/showimg.php ... /Z-058.gif

If I'm reading this right, there should be a yellow wire with a blue stripe going from your disty to the gauge cluster. However, I am not an electrician and am prone to being wrong :lol:

On the other side, I was under the impression these cars stopped being made in 96..? and you have LPG as in Liquid Propane Gas? That's an awesome conversion!! Wires should still be the same tho, hopefully. GOOD LUCK!!

Re: How to measure signal for tachometer?

Posted: January 14th, 2015, 4:46 pm
by Daninski
This post is found in the FAQ section. I'm a---uming yours is a V6? viewtopic.php?f=23&t=69006 On the 96/97 two of the 3 wires on the 3 wire disty plug are reversed as you can see. If you don't use the resistor the tach will not work.

Re: How to measure signal for tachometer?

Posted: January 15th, 2015, 1:45 pm
by sishi
So 2C pin on cluster connector should give signal for tacho (it cames from distributor 3pin C).
How this signal can be measured? With Voltmeter? If yes, which voltage is at cca 1000rpm?

@MX_Sid
Mazda produce MX-3 up to 1998. Yes I have LPG (liquid petroleum gas).

@Daninski
Yes I have V6 (I wrote it). I find your link already before but this is wiring for TOT57271. I assume it's same as for my TOT57171.

P.S. I don't know how to paste the picture into post.

Re: How to measure signal for tachometer?

Posted: January 18th, 2015, 6:36 am
by sishi
Hello,
Can anybody tell me how to measure tacho signal?

Re: How to measure signal for tachometer?

Posted: January 18th, 2015, 4:59 pm
by Daninski
Disties are not the same. No cam sensor in yours and like I said the 3 wire plug is wired differently. Can't remember the wire order on the cap.

Re: How to measure signal for tachometer?

Posted: January 19th, 2015, 12:03 pm
by sishi
Hi Daninski,
I'll find it, what would like to know is how can I measure tach signal?

Re: How to measure signal for tachometer?

Posted: January 22nd, 2015, 10:56 am
by crazycanadian
You need a lap scope. I don't have a V6 car with a distributor other wise I would take a picture and show you.