Tractor Lights - Electrical
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=166294
Printed Date: 18 Aug 2025 at 5:29am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Tractor Lights - Electrical
Posted By: John-Paul
Subject: Tractor Lights - Electrical
Date Posted: 02 Dec 2019 at 2:40pm
| I have a 1964 D15. There are currently 2 headlights and one light facing backwards. They are all connected via 1 wire. I bought some new LED lights (12v, 18W by Ironton) to replace the current ones. The new LED lights have 2 wires coming out of them. The specs said that they are for DC use, like for a tractor. Is it possible to use these new ones or did I purchase the wrong type of light? If I can use them, do you have any tips for making it happen? Thank you! |
Replies:
Posted By: Sugarmaker
Date Posted: 02 Dec 2019 at 2:45pm
|
john, one hot , one ground? regards, chris ------------- D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet. |
Posted By: John-Paul
Date Posted: 02 Dec 2019 at 3:00pm
| No specs came with the lights. However, there is 1 black wire and 1 red wire. I am not sure about the coloring regarding DC wiring. Thanks! |
Posted By: Bear Taylor
Date Posted: 02 Dec 2019 at 3:16pm
| The hot wire (positive) will be the red one and the black wire will be the ground (negative). The black wire can be attached to the metal frame/chassis of the tractor. |
Posted By: Bear Taylor
Date Posted: 02 Dec 2019 at 3:26pm
| We had an old JD-model D that was a positive ground instead of a negative ground. It made us reverse our way of thinking when dealing with wiring issues. |
Posted By: John-Paul
Date Posted: 02 Dec 2019 at 3:32pm
| Ok, so replace the current 1 wire with the new red, and the new black gets grounded - correct? Thanks! |
Posted By: jaybmiller
Date Posted: 02 Dec 2019 at 3:36pm
|
YIKES ! Confirm that the tractor IS negative ground BEFORE wiring up the LEDs !! The package or website should( must ?) have the colour code information as to which wire is +ve and -ve. If it says 'nonpolar' or ' no polarity' or 'universal' then it doesn't matter how you hook them up. The 'universal' LEDs run power through a 10 cent bridge rectifer making them idiot proof to install............ Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: John-Paul
Date Posted: 02 Dec 2019 at 5:36pm
| Will do. Thanks! |
Posted By: MACK
Date Posted: 02 Dec 2019 at 8:02pm
| If they are wired up wrong, they will not light. Just reverse wires. MACK. |
Posted By: John-Paul
Date Posted: 02 Dec 2019 at 10:39pm
| Thank you! |
Posted By: jaybmiller
Date Posted: 03 Dec 2019 at 7:07am
|
You need to be careful about hooking up backwards ! Unless the unit has 'reverse polarity protection' ,anything other than a very,very quick connection can blow the LEDs. Tis the 'nature of the beast'..super bright for a microsecond or two, then poof.. forever darkness. Good LED units will have an internal diode ,so no harm. Great LED units will use a bridge rectifer and be labelled 'universal hookup' or 'idiotproof'. Either only adds maybe 10 cents to the product. Red 'should' be +ve , Black 'should' be -ve but I wouldn't bet my D-14 on it ! Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Flyer
Date Posted: 03 Dec 2019 at 9:05am
|
If hooking up the LED backwards hurts it, something was wrong with it to begin with. Reversing the polarity won't hurt the LED unless the applied voltage is greater than the breakdown voltage for the LED. The breakdown voltage for these should be greater than 50V for a diode in a 12V application. Thing to remember is that a bridge rectifier is just a collection of 4 diodes with 2 of them reverse biased at any given time. ------------- An optimist sees the glass as half full. The pessimist sees the glass as half empty. The engineer sees a glass with double the required capacity. |
Posted By: jaybmiller
Date Posted: 03 Dec 2019 at 9:30am
|
Typical white LED reverse voltage is 5 volts, so applying 12 volts 'backwards will destroy the LED It's one of those 'physics' laws. If done very quickly though, not enough current flows and it might not be destroyed. The problem with '12 volt LED lights' is I (we) can't see what's inside the fancy housing. Cheap(low cost) units could just be a simple one resistor- one LED. Better ones will have 3 LEDS in series with one resistor. Even better ones ,some kind of 'reverse polarity protection'. Best ones will have a voltage to constant current 'module', as LEDs are a current driven device, not voltage. Those units probably have protection builtin. The problem is NOT being able to see 'what's under the hood' and ZERO standards for wire colour codes. The joy of those with bridge rectifires is that it doesn't matter about polarity. They work on +ve grounded vehicles, -ve grounded vehicles and will even operate from AC. Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: John-Paul
Date Posted: 03 Dec 2019 at 10:07am
|
I finally made it out to check the grounding on the tractor. It has a negative ground. The black wire attached to the - (minus sign) terminal on the battery is going to the engine block. I appreciate the warning about a positive ground. I didn't even know such a thing existed. I guess I am ready to install the new lights. I appreciate everyone's help!! |
Posted By: Flyer
Date Posted: 03 Dec 2019 at 1:24pm
There's a lesson in there about getting what you pay for. A buddy of mine got some cheap LED 1157-type replacements he wanted to use for the tail lights on his car. Any time you turned on a turn signal, the opposite park light would flash along with the intended turn signal. I cut one open to discover that they used a dropping resistor inside to dim the bulb for tail light duty. When you lit the bulb through the other contact for the turn signal, the opposing tail light was back-fed through the resistor. ------------- An optimist sees the glass as half full. The pessimist sees the glass as half empty. The engineer sees a glass with double the required capacity. |
jaybmiller wrote:Posted By: jaybmiller
Date Posted: 03 Dec 2019 at 2:11pm
|
neat...a 1 cent diode in series for the tailight LED would have cured that... ...reminds me that NOW 'they' sell CAN rated LED bulbs. They contain power robbing 'bleeder' resistors to make the LED bulb look like a regular incandescent so the 'computer' won't think the bulb's burned out ..... Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |