Deere 4020 schematic
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=208564
Printed Date: 19 Oct 2025 at 11:33am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Deere 4020 schematic
Posted By: Mrgoodwrench
Subject: Deere 4020 schematic
Date Posted: 17 Oct 2025 at 7:57pm
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Anyone out there have an actual schematic for a 12v 4020 diesel? I’m doing an injection pump conversion and have lost power. The only thing working is the headlamps. Odd thing is that I have power to 2 of the three circuit breakers but I thought the dead one was the lights….. ------------- There are 3 ways to do job GOOD, FAST, CHEAP. YOU MAY CHOOSE 2. If its FAST & CHEAP it won't be GOOD, if it's GOOD & CHEAP it won't be FAST, and if its GOOD & FAST it won't be CHEAP!!!! |
Replies:
Posted By: pirlbeck
Date Posted: 18 Oct 2025 at 7:42am
| If this is a side console tractor there is an inline fuse under the dash cowl on the LH side. To the left of the PTO lever. If that fuse is bad you will not have any power to the key switch circuit. Also, once again if it is a side console tractor there are 2 heavy wires that connect to the alternator battery terminal, that originally both wires were crimped into one terminal end, check to make sure these 2 wires are connected. |
Posted By: Mrgoodwrench
Date Posted: 18 Oct 2025 at 11:13am
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Thanks I’ll check both of those. I think I may have shorted the fuel cut circuit while I was testing it, so a fuse makes sense. ------------- There are 3 ways to do job GOOD, FAST, CHEAP. YOU MAY CHOOSE 2. If its FAST & CHEAP it won't be GOOD, if it's GOOD & CHEAP it won't be FAST, and if its GOOD & FAST it won't be CHEAP!!!! |
Posted By: pirlbeck
Date Posted: 18 Oct 2025 at 11:14am
Is this a side console tractor?
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Mrgoodwrench wrote:Posted By: Mrgoodwrench
Date Posted: 18 Oct 2025 at 12:14pm
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Yes it is ------------- There are 3 ways to do job GOOD, FAST, CHEAP. YOU MAY CHOOSE 2. If its FAST & CHEAP it won't be GOOD, if it's GOOD & CHEAP it won't be FAST, and if its GOOD & FAST it won't be CHEAP!!!! |
Posted By: pirlbeck
Date Posted: 18 Oct 2025 at 12:37pm
I figured that it must be as prior to 1969 and the introduction of the side console tractors they did not have a 12 volt solenoid shut off on the injection pump, although I have seen some added when a later engine was swapped in. Also, you mention an injection pump changeover which more then likely means you are replacing the CB injection pump with the JDB pump.
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