MTFCA Forum

I have a 1926 Ford Model T Coupe and have purchased a metal shut-off switch to disconnect all voltage when not in use. I’m not sure where to install it. Was thinking below driver’s side of the seat near and above the starter foot button. Any suggestions as to where, how, and which wires. Many thanks in advance for any input.

That would be a convenient position - best to able to get to it in an emergency also. I utilize the negative battery connection to interrupt the voltage current.

acereske wrote: ↑

Sat Jul 09, 2022 6:06 pm

I have a 1926 Ford Model T Coupe and have purchased a metal shut-off switch to disconnect all voltage when not in use. I’m not sure where to install it. Was thinking below driver’s side of the seat near and above the starter foot button. Any suggestions as to where, how, and which wires. Many thanks in advance for any input.

It all depends on what style cutoff switch you purchased. There are variations of these styles

Probably a good place for it at the edge of the seat. I have in the past used one at the negative battery terminal, but have to remove the floorboard to reach it and also a prime location for corrosion from battery acid.
Norm

Are you considering hiding it? In order to prevent theft or random people playing with it, not to mention keeping a good charge in the battery and preventing any damage from random short circuits, I prefer to hide the switch but keep it in a readily accessible location.

The manufacturers recommend placing the switch in the HOT wire line as opposed to the GROUND wire line. The reason being, doing it this way, there are many fewer places a hot wire can come in contact with a ground. Also, any thief will not be able to jump from the battery ground to the frame and have power to the vehicle. Harder to run a jumper from the battery hot terminal to supply power to the entire vehicle.

This is written in a supportive mode and NOT meant as a "You're doing it wrong" attitude. I respect everyone's perspectives and choices.

I've used the green knob one and do NOT recommend it. In this case, less expensive means wears out faster. I have also used the knife switch type. The bottom connector is plastic and will break if abused. It also has the potential for corrosion. I recommend the closed switch types. Not meaning to bring up ill feelings, Harbor Freight has a nice "keyed" switch. This is just as an example. There are other manufacturers making higher quality switches of this type, still at an affordable price.

Good Luck,

I used this $30 rig I got from Lang's. It's the red flipper on the left of the picture. It's a heavy duty switch, not like cheapo red plastic key stuff.

Wired to the (+) from the battery. When switch Is on, the main harness and the input side of a 6v solenoid are live. The solenoid has a button wired to it, see right side of picture. When button is pushed it allows current thru and out of the other side of the solenoid to the starter.

I did away with the floor mounted starter switch, as I had mine break and weld the starter on!
Had the shutoff not been so handy, I could have had a major setback in a quick minute.

This is one major reason to have quick access to your shutoff switch.....
Starter was stuck on with the engine running. Without the switch I was done.....

On the seat riser is where I installed mine on my 25 coupe.

I'm not been worried with theft more than just a safety item & better within reach of the operator's station. Most of you are familiar with John Regan & being an electrical engineer, advised on mounting any type of electrical interruption switch to be mounted on the negative side.

Yes on the negative side! On 26-27 with the gas tank in the cowl mounting the switch on the seat frame is OK. But on earlier cars I would hate to forget to turn the switch on and have the starter ground threw the gas tank? Even on the ground side arching can occur when disconnecting a load. I install mine as close to the battery as I can so I can hook the ground cable direct to the switch this is not convenient but effective. I installed a continuous duty solenoid on my granddaughters Jeep ( stands for Just Empty Every Pocket) that has body module issues (Very common on Jeeps) It disconnects everything but the switch to turn it on and has been working for a long time. gets driven a lot more than most Ts Again don't switch off with a load on it
Craig.

Again, thanks for all the great support and ideas. Now all I have to do is get it installed as I bought the heavy duty switch from Lange’s last year.

I know it's overkill, but I used a 20 amp pushbutton to activate my 6v three pole solenoid.