Tach signal problem - Ford Mustang Forums : Corral.net Mustang Forum
 
LinkBack Thread Tools Display Modes
post #1 of 5 Old 06-15-2012, 12:05 AM Thread Starter
Registered User
 
Trader Feedback: (1)
Join Date: Apr 2012
Location: Indianapolis
Posts: 73
Tach signal problem

# #14
apaulk86
Registered User

Trader Feedback: (1)
#
Join Date: Apr 2012
Location: Indianapolis

I'm having a tach signal problem on my 96 gt. My stock tach worked fine for a long time and then it would randomly go out on me and after that happened, it would only work when it rained. Since that happened in assuming that there is a loose ground under the hood somewhere. Anyone have and ideas for me??? I now have an aftermarket I hooked up but no good tach signal. And also, how do I test the wire near the ECM?

apaulk86 is offline  
Sponsored Links
Advertisement
 
post #2 of 5 Old 06-15-2012, 06:34 AM
Registered User
 
wmburns's Avatar
 
Trader Feedback: (0)
Join Date: Apr 2012
Location: Houston
Posts: 272
I would start by confirming ground G203 on cluster pin 7 (BK/W) and ground G103 on cluster pin 9 (BK/Y). Measure back to battery negative. The Ohm reading should be very low.

Ground G203 is located behind the center console. G203 is also shared with many devices including the radio. It's frequently messed up during a radio install.

Next inspect the PCM area and connector for evidence of water or rodent damage.

wmburns is offline  
post #3 of 5 Old 06-16-2012, 05:04 AM Thread Starter
Registered User
 
Trader Feedback: (1)
Join Date: Apr 2012
Location: Indianapolis
Posts: 73
Quote:
Originally Posted by wmburns View Post
I would start by confirming ground G203 on cluster pin 7 (BK/W) and ground G103 on cluster pin 9 (BK/Y). Measure back to battery negative. The Ohm reading should be very low.

Ground G203 is located behind the center console. G203 is also shared with many devices including the radio. It's frequently messed up during a radio install.

Next inspect the PCM area and connector for evidence of water or rodent damage.
I just read this, and I plan to do the checking later this morning. Something strange happened tonight on my way home from work that hasn't happened in a few months. I took a right hand turn into my neighborhood and saw the tach needle go up for about a second and a half and then shot back down to zero.

Until I check out those grounds tomorrow, I have no clue what the hell to think. This car has a mind of it's own, period. But, if the grounds turn out to be good, then the only other thing left is the tach signal wire coming from the ECM right? The reason I say that is because I have an SCT Livewire tuner and it reads the rpms just fine through the OBD port.
apaulk86 is offline  
Sponsored Links
Advertisement
 
post #4 of 5 Old 06-17-2012, 09:45 AM
Registered User
 
wmburns's Avatar
 
Trader Feedback: (0)
Join Date: Apr 2012
Location: Houston
Posts: 272
Congratulations! You get a gold start for using your grey matter! Yes for the 96-04 MY, the tach signal comes from the PCM. So if the PCM has the correct RPM's, then the problem is in the cluster or wiring.

The tach signal is cluster pin #8 (wire color T/Y).

For the 96-04 MY Mustang, the usual method to get an aftermarket tach is to use a tach adapter. Examples include the Autometer 9117. The tach adapter is necessary due to the way the NDIS ignition works.

Here are some examples:
http://www.autometer.com/productPDF/0561B.pdf


Last edited by wmburns; 06-17-2012 at 09:49 AM.
wmburns is offline  
post #5 of 5 Old 06-22-2012, 04:17 PM Thread Starter
Registered User
 
Trader Feedback: (1)
Join Date: Apr 2012
Location: Indianapolis
Posts: 73
Quote:
Originally Posted by wmburns View Post
Congratulations! You get a gold start for using your grey matter! Yes for the 96-04 MY, the tach signal comes from the PCM. So if the PCM has the correct RPM's, then the problem is in the cluster or wiring.

The tach signal is cluster pin #8 (wire color T/Y).

For the 96-04 MY Mustang, the usual method to get an aftermarket tach is to use a tach adapter. Examples include the Autometer 9117. The tach adapter is necessary due to the way the NDIS ignition works.

Here are some examples:
http://www.autometer.com/productPDF/0561B.pdf

Auto Meter 9117 Tach Adapter Install - YouTube
Thanks for the tip but I was able to tap into that wire without spending another 78 dollars on an adapter. The tan yellow wire was just slightly broken at the plug
apaulk86 is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forums : Corral.net Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Stock tach problem ajdiebo Electrical & Wiring 3 05-06-2012 11:10 AM
Random misfire problem? chargedWS6 5.0/5.8 Engine Tech 4 04-16-2012 04:39 AM
Opinions on breaking up problem mw95gt Turbochargers 18 06-13-2011 12:40 PM
starting problem 94whtlite#2669 General Mustang Tech 1 06-12-2011 10:25 PM
Four Cylinder Ignition Problem lmacklem 5.0/5.8 Engine Tech 3 12-17-2001 03:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome