I put a complete new wiring harness on an 856 I restored a year ago, and remember the air restriction indicator wiring well. Assuming an 856 and 1566 use the same system, this is how the 856 system works. The green / red gauge defaults to the red zone when no power flows through the gauge. The restriction gauge takes power from the ignition switch to one gauge terminal and grounds the other gauge terminal through the sender at the air cleaner. The sender at the air cleaner has two terminals, one is connected to ground near the sender and the other terminal connects to the gauge terminal. The sending uniot at the air cleaner is just an on / off vacuum switch so normally it grounds the gauge which puts the needle in the green zone. When restriction vacuum gets high enough, it opens the sender switch, which opens the gauge circuit to ground and allows the needle to swing to the red zone.
If yours remains in the red zone, look for no power to the gauge, or an open circuit in the ground circuit, through the sender switch to ground on the engine. If the gauge is known to be good, your problem has to be in the 12V supply circuit to the gauge, or in the ground circuit that goes through the sender switch to ground on the engine.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Antique Tractor Wiring Basics - by Curtis von Fange. One of the most neglected parts of old tractors is the wiring. After sitting in the elements for half a century or more much equipment wiring has deteriorated to sparsely covered strands of copper or other metal. Plastic insulation has cracked, mice have eaten through the older clothed style coverings and the exposed wires have reacted to winter moisture and salts by turning blue and powdery. Terminal ends have corroded, rusted or just plain evaporated away. Aged wires not only keep an engin
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
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.
