Yesterday's Tractor Co. Fast, Friendly Parts Service
Click Here or call 800-853-2651 
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 
Marketplace
Tractor Manuals
Tractor Parts
Classified Ads
Photo Ads

Community
Discussion Forums
Project Journals
Tractor Town
Your Stories
Show & Pull Guide
Events Calendar
Hauling Schedule

Galleries
Tractor Photos
Implement Photos
Vintage Photos
Help Identify
Parts & Pieces
Stuck & Troubled
Vintage Ads
Community Album
Photo Ad Archives

Research & Info
Articles
Tractor Registry
Tip of the Day
Safety Cartoons
Tractor Values
Serial Numbers
Tune-Up Guide
Paint Codes
List Prices
Production Nbrs
Tune-Up Specs
Torque Values
3-Point Specs
Glossary

Miscellaneous
Tractor Games
Just For Kids
Virtual Show
Museum Guide
Memorial Page
Feedback Form

Yesterday's Tractors Facebook Page

Related Sites
Tractor Shed
TractorLinks.com
Ford 8N/9N Club
Today's Tractors
Garden Tractors
Classic Trucks
Kountry Life
Enter your email address to receive our newsletter!

subscribe
unsubscribe
  
John Deere Tractors Discussion Forum
Show Parts for Model:

4050 analog tach -- testing crankshaft sensor

Author  [Modern View]
cob_crusher

11-28-2009 11:25:32
24.213.205.227



Report to Moderator

deere 4050 with analog tach. prev post said to check for 0.8 volts AC. there are two wires going to and from crankshaft position sensor ( red & blue). when at low idle should one wire show volts coming to the sensor ? which wire red or blue ? should this be DC volts ? other wire (from senor) should show 0.8 volts DC or AC ?




[Reply]   [No Email]
cob_crusher

11-28-2009 14:18:41
24.213.205.227



Report to Moderator
 Re: 4050 analog tach -- testing crankshaft sensor in reply to cob_crusher, 11-28-2009 11:25:32  
sensor read 0.52 vac, then increase rpm giving 0.56, increase giving 0.58. sensor should be aok. does tach end plug have two wires so i can check continuity and vac increase ?



[Reply]  [No Email]
Lee B

11-29-2009 17:31:16
208.123.145.77



Report to Moderator
 Re: 4050 analog tach -- testing crankshaft sensor in reply to cob_crusher, 11-28-2009 14:18:41  
You have a simple magnet and coil generating the AC pulses in the sensor. It would be normal for the voltage to rise when speed increases.

The other end of the wires must complete the circuit in order for it to work so YES, you can check continutiy at the tach end of the wires provided you have access to them.

With voltages these low, wiring problems occur with the slightest leak of either water or oil into connectors or wires themselves. Even when all connections are clean and sealed, signals can get lost when they start out at .52 volts. One tool to use in this event would be Radio Shack's Contact cleaner, it will clean connections and prevent further contamination if used with current weather proof connections likely to be found in your tach sender circuit.

[Reply]  [No Email]
buickanddeere

11-28-2009 14:31:10
216.183.152.179



Report to Moderator
 Re: 4050 analog tach -- testing crankshaft sensor in reply to cob_crusher, 11-28-2009 14:18:41  
It's frequency/pulses, not voltage that is sending the signal to the tach.



[Reply]  [No Email]
Bob

11-28-2009 11:39:21
69.178.228.68



Report to Moderator
 Re: 4050 analog tach -- testing crankshaft sensor in reply to cob_crusher, 11-28-2009 11:25:32  
Check for AC voltage BETWEEN the two leads from the pickup coil.



[Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Add a Reply]

Hop to:
TRACTOR   PARTS TRACTOR   MANUALS
Same-Day Shipping! Most of our stocked parts ship the same day you order (M-F).  Expedited shipping available, just call!  Most prices for parts and manuals are below our competitors.  Compare our super low shipping rates!  We have the parts you need to repair your tractor.  We are a Company you can trust and have generous return policies!   Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ More Info ]

Home  |  Forums


Copyright © 1997-2014 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters