Farm Equipment - Broken Tach on 7040

Print Page | Close Window

Broken Tach on 7040

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=26690
Printed Date: 26 Feb 2025 at 10:31pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Broken Tach on 7040

Posted By: NYREDPOWER
Subject: Broken Tach on 7040
Date Posted: 03 Mar 2011 at 9:03pm

Ive been getting to know my 7040. I understand it is common for the tach to be broken what should I do to fix it thanks

Replies:

Posted By: MACK
Date Posted: 03 Mar 2011 at 9:18pm

Is it broken or don't work? MACK

Posted By: NYREDPOWER
Date Posted: 03 Mar 2011 at 9:21pm

it does not work

Posted By: monitordoc
Date Posted: 03 Mar 2011 at 10:59pm

NEIHOFF (SPELLING) ALTERNATORS DID A NUMBER ON MANY 70 AND 80 SERIES TACHS. MOST ARE REPAIRABLE.

PM ME FOR MORE INFO.

-------------
WD,D17-S4,180,D21

Posted By: scott
Date Posted: 04 Mar 2011 at 6:39am

Since the day I got it my 7040 tach has not worked. Hr meter yes, tachometer no. I licked my finger and drew a line on the dash and thats where the throttle lever goes.

Posted By: MACK
Date Posted: 04 Mar 2011 at 7:54am

Don't know which alt. you have, but if it is a delco with the stub plugin on back the connection could be the problem. Could be a set of windings burned up in alt. Should be a small brown wire hooked to alt. check for bad connection in plug in between back of motor and fire wall. MACK

Posted By: jmm
Date Posted: 04 Mar 2011 at 2:32pm

As a matter of interest: I had the same problem and when I replaced the alt I used a cheapy model for a GM (fit perfect) and opened it up and tapped the tach wire before the rectifier. works good!