Headlight wiring
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=200163
Printed Date: 04 Dec 2024 at 3:31pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Headlight wiring
Posted By: ElementalEarth
Subject: Headlight wiring
Date Posted: 06 Mar 2024 at 7:19pm
 I removed the ammeter and replaced it with a voltmeter according to this diagram. Now what I am wondering, where should I connect the line for the headlights to, to do so safely. I have a 20amp fuse and some 12 gauge wiring laying around that I had planned to use. Can I piggyback off the battery terminal on my keyswitch, put a fuse inline to the headlight switch? My key switch does not have an accessory terminal unfortunately. And theres already too many wires on the hot post of my solenoid. |
Replies:
Posted By: steve(ill)
Date Posted: 06 Mar 2024 at 7:45pm
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coming off the key switch puts more amp draw thru that switch.. How GOOD is that switch ?... Also, do you need the lights to work when the key is OFF ? You can come off the battery terminal to your LIGHT switch ... or the POWER into the key switch..if you want to be able to work the lights with key off. ------------- Like them all, but love the "B"s. |
Posted By: ElementalEarth
Date Posted: 06 Mar 2024 at 8:57pm
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I was hoping to do a Y- spade terminal on the battery post of the key switch. Does that mean the power draw to the lights still goes through the switch? Sorry my knowledge is rather limited. Definitely don't want to overload the keyswitch, looks pretty cheap that thing. How are headlights usually wired in? According to my original schematic in the manual it does look like joined at the battery post of ignition switch, from there on out fuse and then to headlight switch. |
Posted By: steve(ill)
Date Posted: 06 Mar 2024 at 9:01pm
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YES... that would be a good way to do it... Take the power BEFORE it goes thru the ignition switch... Your LIGHT switch can turn lights on and off... Connect to the battery wire going TO the KEY SWITCH. ------------- Like them all, but love the "B"s. |
Posted By: ElementalEarth
Date Posted: 06 Mar 2024 at 9:08pm
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Sounds good, thanks steve. Any objections to using a busbar to run all the hot wires? Seems like a good way to be able to distribute the power to the different lights without a tangled mess of splices or connectors. Im always looking for the cleanest, safest option when it comes to wiring. |
Posted By: steve(ill)
Date Posted: 06 Mar 2024 at 9:32pm
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I have used terminal blocks in many areas. ------------- Like them all, but love the "B"s. |
Posted By: Steve in NJ
Date Posted: 07 Mar 2024 at 8:50am
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One thing to keep in mind. If you wire the Headlight switch hot all the time, unless you have a disconnect switch at the Battery, that circuit will always be hot. If the Tractor sits in a barn or shed where the varmits hide and get into the Tractor, and they decide to have lunch and chew through that hot circuit, the fuse may or may not blow leaving a hot circuit bare possibly causing a short which you will not be aware of unless the Voltmeter picks it up showing an overcharging problem which brings the possible problem to your attention before something happens. Wiring the headlight switch off the accessory or IGN post of the key switch, would be the safer route being that particular circuit will only be hot when the key is ON or the Tractor running. Standard Headlights and a tail light do not put that much load on the key switch, especially if you're running a 3 wire system and the voltage sense circuit is up near the dash where current is high. You can wire it either way as Steve mentioned, but as I said, don't rely totally on the fuse to protect the circuit. If you have additional spot or stadium lights, you should wire a separate circuit with a relay (or two) in that circuit with a seperate push/pull or Headlight switch to handle the higher load that stadium lights or additional spots can put on the system if the Headlights are on as well. The relay(s) will take the load off of the Headlight switch. BTW, if using these types of lighting, never use a toggle switch! Most standard toggle switches are only rated at 10-15 amps. Depending on what type of lighting and how much determines the load put on the switch. A good high amp push/pull switch such as a Cole Hersee 75 amp unit would be more than enough for that particular circuit. Its always better to have "overkill" . Moving up a notch on the gauge wire will help as well when wiring in these types of lights. Length of the circuit is important as well. Terminal blocks are an excellent way to keep wiring neat and clean. Using a junction or terminal block is also a perfect spot to connect the voltage sense circuit from the Alternator. This way the VR can control voltage evenly on board the Tractor and keep voltage "balanced" throughout the system. Add a circuit from the Battery to that junction block, and the VR will also keep the Battery "full".... HTH Steve@B&B
------------- 39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife |