Need helping selecting an ignition switch (Cole hersee) for my diesel farmall

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I am in need of a better ignition key switch for my Farmall 826 diesel tractor. I have bad experiences with oem key and button ignition switches always breaking. I heard COLE HERSEE is a good brand for heavy duty ign switches for tractors, but there’s a lot of options to choose and I’m not sure which is right when factoring in the various accessories I have on the tractor.

I have (or will have) the following lighting/electrical parts installed on my tractor:

1. 12 Volt Fuse Block Box (100A max for panel, 6x circuits with 30A max each) I will use this to protect lights/accessories. Currently I have inline 20A blade fuses to protect the ignition/ light switches, usb-c charging port, etc. the wiring under the dash isn’t pretty and requires a lot of forceful stuffing of wires whenever I bolt the panels back on and I want to change that
2. 12v USB-C/3.0 power outlet: charging phone
3. 126w Light + 4pcs 18w LED Pods: replacement for nnalert halogen lights on tractor
4. OEM blower motor/fan for the year-a-round cab. Don’t know the specs other than that it is on one of those self resetting 20A circuit breakers that is bolted to the frame
5. Windshield wiper motor. Same as blower motor, but it has its own 20A breaker.
6. Ether solenoid button. Currently using OEM as I’ve never had an issue with it. Unsure of specs/amp usage
7. 12v digital voltmeter
8. Fuel gauge & sending unit (aftermarket from YT); PN: 107954 & PN: 121190
9. Universal aftermarket temperature gauge PN: 186993

Once I have the switch, my plan for wiring the above was something along the lines of:

A) wire in the ignition switch (I am using a 63A internally regulated/one wire alternator)
1a) 10 awg wire from alternator to BAT post on starter
2a) 4/0 awg battery cable from battery positive post to starter’s BAT post
3a) 10 awg wire from starter’s BAT post to ignition switch’s BAT post
4a) 10 awg wire from ignition switch’s START post to the START terminal on the starter solenoid

B) wire in the fuse block for powering accessories & lighting
1b) install fuse block somewhere to tractor’s firewall (probably the empty area under steering wheel)
2b) run 6 awg wire from POS post on battery to the positive on fuse block
3b) 6 awg from NEG battery to negative on fuse block

C) wire in lights
1c) 20A (or 30A?) fuse with 12 awg wire to line on the power on/off switch for lights (all of them are powered by one switch as they are LEDs, unless so should split it between two?)
2c) 12 awg from switch to load to power the lights
3c) 12 ground from switch to neg bus on fuse block
4c) lights grounded to frame, 12 awg

D) ether solenoid/switch
1d) 12 awg from fuse/pos to oem ether switch (20A fuse)
2d) 12 awg from ether switch to solenoid spade terminal #1
3d) ether solenoid spade terminal #2 to ground with 12 awg wire

E) usb charger
1e) 10A fuse, 14 awg wire from positive fuse block to hot spade terminal on charger
1e) 14 awg wire from negative bus to negative spade terminal

F) blower motor/windshield wiper
These already each have their own inline 20A self resetting circuit breaker, could this just be connected to the accessory post on the ignition keyswitch to prevent battery drain vs just connecting directly to the battery?

G) voltmeter
Should this be connected directly to battery or also to the accessory post on ign switch? I’ve read it’s better to go directly to battery sometimes, but then it’s continually draining the battery?

H) fuel gauge/sending unit
Never had a working one of these on any of my older tractors. All I remember is reading about needing to be careful about connecting it to the correct wire (either the light blue, NOT the dark blue, or vice versa, based on OEM wiring scheme) or else it’ll get fried.
So…I don’t have a clue how this would factor into my electrical configuration.

 

[Jim Becker]

Powering all that stuff through the ignition switch? no wonder you have trouble with the switches. Get a heavy duty relay. Let it power your fuse block and use any cheap ignition switch to control the relay.

 

[Janicholson]

Powering all that stuff through the ignition switch? no wonder you have trouble with the switches. Get a heavy duty relay. Let it power your fuse block and use any cheap ignition switch to control the relay.

an example.
Exactly the answer. Any sub system that does or can draw 15 to 20 amps should be relay controlled. Nich plastic boxes (or premade relay panels with covers are good. Jim

 

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an example.
Exactly the answer. Any sub system that does or can draw 15 to 20 amps should be relay controlled. Nich plastic boxes (or premade relay panels with covers are good. Jim

What’s the difference between the fuse block and the relay you linked to? (if you google the first sentence of item #1 the link to a certain Amazonian website should pop up with the exact one I have)

I’ve never really understood how to use or wire in those kind of relays

 

[Janicholson]

What’s the difference between the fuse block and the relay you linked to? (if you google the first sentence of item #1 the link to a certain Amazonian website should pop up with the exact one I have)

I’ve never really understood how to use or wire in those kind of relays

A relay is designed to have a fused input from a direct battery source. It is a remotely operated switch with (usually) 4 terminals. one ground and one activation terminal that operate a magnetic coil. and two terminals that are the switch. One connected to fused constant power, the other connected to the load (lights, AC compressor, or other load. This allows a small electrical current in milliamps to operate a substantial load. Thus freeing the Key switch from heavy current through its contacts. Jim

 

[M-MAN]

I don't understand the overkill on most of the wiring and then put a little 4g automobile battery cable on it? Diesel ought to have a 1/0 minimum battery cable and a 00 would be best. JMO

 

[Fritz Maurer]

I don't understand the overkill on most of the wiring and then put a little 4g automobile battery cable on it? Diesel ought to have a 1/0 minimum battery cable and a 00 would be best. JMO

He said 4/0.... which is enough to start a 16V149 with tandem starters.

 

[BarnyardEngineering]

You've thought about this way more than pretty much anyone would.

Neither the key switch nor the starter button should be carrying any significant current. If they are you have it wired wrong.

What problems are you having with the OEM switches and buttons?

 

[used red MN]

You probably need something more like this. Constant on relay The small terminal would be powered when the key is in the on position. This closes the contacts across the two large terminals. You would run your 6awg from the battery terminal on the starter to one of the large terminals. Then the other side would be your 6awg to the fuse block to power whatever you want to turn on and off with the key. You would jumper between the terminal that you connect your 6awg to and the other fuses you want switched. That all depends if your fuse block has on terminal to feed all the fuses or if they are separated. With this as Jim Becker said the only load on your switch is the small amount of current needed to pull the contactor winding in.

 

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You probably need something more like this. Constant on relay The small terminal would be powered when the key is in the on position. This closes the contacts across the two large terminals. You would run your 6awg from the battery terminal on the starter to one of the large terminals. Then the other side would be your 6awg to the fuse block to power whatever you want to turn on and off with the key. You would jumper between the terminal that you connect your 6awg to and the other fuses you want switched. That all depends if your fuse block has on terminal to feed all the fuses or if they are separated. With this as Jim Becker said the only load on your switch is the small amount of current needed to pull the contactor winding in.

Yeah I think that’s what I want. I have an old research combine that has it set up like that with a solenoid looking type relay that has the main load (which powers the fuse block) opened/closed via the key/ignition switch’s accessory function. My 504’s glow plug relay works the same way (but is an actual glow plug relay not a typical accessory relay).

Would I need a fuse to go between the starter and the relay, or between the relay and the fuse block? Or both? It shows the continuous working amperage for that relay as 125A, and my fuse block is 100A. Would I have a 125A fuse between the starter and relay, and then 100A fuse between relay and fuse block, or just 100A for both since the fuse block caps at 100A anyways?



I was going to ask whether Something like this would work, as my tractor with gps system has one of those which is used to power some part of it (the navcontroller maybe?). I’ll probably end up buying the kind of relay you linked to as I can understand it easier, but out of curiosity would one of those solid state relays work?

 

[used red MN]

The fuse you choose only protects the wire or other items in your circuit. It’s not like the second you connect a 100 amp fuse block that your load is immediately 100 amps. A 6 awg wire is good for 60 amps so that is probably the fuse you want. Even that is probably beefing up the circuits quite a bit from stock. Say you connect the heater blower, wipers and lights each with a 20 amp fuse. None of those items draws 20 amps continuously, only if there was some type of failure (I.e. bad motors) in all 3 simultaneously that increased their load to near 20 amps each would the circuit start to be taxed. This would be a “planet alignment” scenario. The solid state relays in your link would probably work per their specs, I have no personal experience with such items. The ones shown are only 25 amps. I personally would connect any lighting to be powered all the time, not controlled by the key switch. If you’re using a relay like this it doesn’t really matter. Originally it was done to keep the higher amp load off the ignition switch contacts and most things with lights have always been wired that way.

 

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The fuse you choose only protects the wire or other items in your circuit. It’s not like the second you connect a 100 amp fuse block that your load is immediately 100 amps. A 6 awg wire is good for 60 amps so that is probably the fuse you want. Even that is probably beefing up the circuits quite a bit from stock. Say you connect the heater blower, wipers and lights each with a 20 amp fuse. None of those items draws 20 amps continuously, only if there was some type of failure (I.e. bad motors) in all 3 simultaneously that increased their load to near 20 amps each would the circuit start to be taxed. This would be a “planet alignment” scenario. The solid state relays in your link would probably work per their specs, I have no personal experience with such items. The ones shown are only 25 amps. I personally would connect any lighting to be powered all the time, not controlled by the key switch. If you’re using a relay like this it doesn’t really matter. Originally it was done to keep the higher amp load off the ignition switch contacts and most things with lights have always been wired that way.

How’s this look so far? Waiting on a new relay as the one I managed to break the positive switch wire post that activates the relay solenoid from the ignition switch’s acc post.

The other end of the large red wire will attach to the starter’s battery post along with where the alternator & BAT wire that feeds to the ignition switch are (or directly to battery?). and the large black wire I will attach direct to battery negative for best grounding connection.

Incase it’s hard to tell, I’m using that plate right under the steering wheel where the voltage regulator/resistor used to be before I swapped for a better internally/self reg alternator. Lot of empty space there and it’s a convenient location to feed wires from that I can access by just removing 2 bolts

I will then have a wire go from the buses to my
1) 20a fuse to light switch (1, possibly 2, idk)
2) 20a fuse to solenoid switch
3) 20a fuse blower motor & windshield wiper (can I double tap these two to a single screw?)
4) 5 or 10a fuse to USBA/C charger

Then the remaining 2 screws I haven’t decided on anything yet/spare room for any expansion

 

[used red MN]

Looks good, probably 100 times better than the stock setup. I see a square hole in the constant-on relay at the top. What kind of connection powers it’s pull in coil?

 

[Fixingfarmer]

Looks good, probably 100 times better than the stock setup. I see a square hole in the constant-on relay at the top. What kind of connection powers it’s pull in coil?

It does look good!! reminds me of a lot of heavy equipment setups in the battery box. You could open a modern terragator cover and have essentially the same setup. Probably what we all should be doing really.

that is likely where the post was he broke. Might need a bit more robust solenoid agco and caterpillar had some called a trombetta solenoid with some heavier terminals. space is probably limited in there though.

 

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Looks good, probably 100 times better than the stock setup. I see a square hole in the constant-on relay at the top. What kind of connection powers its pull in coil?

It does look good!! reminds me of a lot of heavy equipment setups in the battery box. You could open a modern terragator cover and have essentially the same setup. Probably what we all should be doing really.

that is likely where the post was he broke. Might need a bit more robust solenoid agco and caterpillar had some called a trombetta solenoid with some heavier terminals. space is probably limited in there though.

Yeah that’s where it broke. I lost the original nut and the one I tried to use as a replacement wasn’t a fit (must be metric or something), and ended up crossthreading the post and breaking it loose. Then I just tore it off out of curiosity to look inside

 

[DeltaRed]

You are running way too much stuff off a simple switch. The light switch,the glow plugs;cab and other accessories ,each have a seperate circult,independant of the key switch.

 

[used red MN]

You are running way too much stuff off a simple switch. The light switch,the glow plugs;cab and other accessories ,each have a seperate circult,independant of the key switch.

DR, The solenoid is not for the starter. It is a constant-hold unit, it is going to be used as a relay or a contactor as would be in a AC system like for a HVAC compressor. The only power through his switch will be to operate the coil in the solenoid. He posted what he wanted to do, I gave him directions how to do it.

 

[560Dennis]

 

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You are running way too much stuff off a simple switch. The light switch,the glow plugs;cab and other accessories ,each have a seperate circult,independant of the key switch.

They do, that’s what the 6 circuit fuse block is for