On my 25 TT where is a good place to install a battery cut off switch
My dad has a 23 and put his right on the battery post. It should be pretty easy to access right there by the running board. I have a 26 pick up and I put mine on the battery post as well. You can get one from most any auto parts store that is a simple knife switch which clamps to the battery post in place of the battery cable and had a place of the battery cable to hook up to.
YUP.... nothing like an open knife switch by a battery gassing off hydrogen fumes. Whats the switch for? anti theft?
Just to disconnect the battery while it is sitting
Ronnie - the screw/knob disconnect that goes right on the post will fit nicely under the lid of the battery box. All the vendors sell them - about $10. My '24 C-cab had one ("had" only because I no longer own the truck) and it worked well. There is a more expensive master kill switch, also works well but is pricey. I keep disconnects on all my doodlebugs - kids will climb on them at shows and it keeps the drama down when a kid, in his/her excitement, inadvertently steps on a starter button.
Getting really tiresome to note the frequency of how people coming to this Forum looking for help are met with outright snark and derision.
My experience with the battery cutoff which goes at the battery terminal is this: It got corroded and failed me when I was trying to start the car. Fortunately it started on mag with the crank. It is not good for the generator to run with an open circuit to the battery. I was also fortunate that it didn't cause my generator to burn out. Must have been enough high resistance circuit between generator and battery, but too high resistance for the starter to operate.
Now if I want to cut out the battery I just remove the ground strap at the battery post.
I agree with Ron's post about the snide reply's some members leave. Ronnie asked a simple question and was civilly answered by some and not so civilly answered by others. How about we as a group leave the snide comments off when answering questions. As my profile states, "The only pure Model T is Your Model T " Harv
I get a lot of tech calls for electrical problems on T's. The battery cutoff switch is of no real use to solve real problems. It only solves hypothetical problems but it does have a history of causing problems. Most people think that it does the job of a fuse but it does not since a fuse will blow instantly while the disconnect switch must be manually opened I guess while the car is on fire if fire is why it is on there. I strongly suggest you not install a master battery disconnect switch but that you do install a fuse in the heavy yellow wire coming off the foot switch. That works - battery disconnect switch is sold by fear and none of them are made all that well. Since compared to a modern car which has miles of wiring, why do folks assume that a Model T will burst into flames. I have seen some burn but it was because they had no fuse or the owner was careless while working on the car at roadside. Modern cars on the other hand have a history of bursting into flames so why not put one on your modern car if in fact you believe in them? I am not wreckless here but you can inspect all of the T wiring in under 5 minutes so why not do that regularly and let a fuse do the actual protecting since it will blow instantly and permanently if there is a short in your wiring. If you have a small leakage current, why not find it and fix it. If you give me a call I will help you do that. Drop me a PM and I will respond with my phone number.
Here is my response to Ronnie's question and while you may not agree, it is not snide or derisive.
I believe is "NO" useful place for a battery disconnect switch on a Model T. For the most part they are poorly made, nothing but trouble and of little practical use.
If you have a electrical problem with your car that you believe a disconnect switch corrects, find the problem and fix it.
I have worked on many Model T's with electrical problems only to find a disconnect switch the culprit.
The only required safety addition to the Model T electrical system is a 25 amp fuse in the yellow wire near the starter switch. That wire feeds all electrical loads and if these is a problem it will blow.
Ron the Coilman
Ron the Coilman, Your response to Ronnie's question was excellent. I don't mean to imply that a question shouldn't be answered honestly only that it be formatted in a civil and helpful manner. Harv
While his comment might offend those who desire politically correct replies, in this case "Trooper" is exactly correct.
If you have ever witnessed a hydrogen gas explosion of a battery ignited by a spark from connecting battery cables or a disconnect switch you would understand.
Ron the Coilman
Ron Patterson and John Regan are the reasons why people come here looking for help - studied advice and assistance. I always learn something when they post. Pity not everyone on here is like that.
If you have a battery in a pre-starter T, should it have a fuse? If so, how many amps and where?
No one looking for "politically correct" replies here. But a reply that offers pure snark in CAPITAL letters with no solutions or additional advice to the individual who solicited assistance tends to turn even the most calloused of us off after a while.
The bottom line here is that I will be installing a 25 AMP fuse in the yellow wire near the starter switch this morning in my 25 wagon. Thanks, Ron, Ron, And Ronnie - Harv.
Steve - I've read other posts and threads that do recommend the installation of a fuse, as John R describes above, simply to protect the car from any possible problems, with or without a starter. When I replaced all the wiring in my 1919 non-starter (but with generator) speedster, I purchased the kit from Fun Projects. It comes with two 25A fuses. Already replaced one when it blew after I inadvertently shorted the hot wire when installing my voltage regulator. Cheap insurance for your car ($7), especially if you have old or original wiring, IMHO.
Forget the knife switches. They corrode at the pivot point and get hot when using the starter, especially on 6 volt systems.
The collector I worked for several years bought Ronald Reagan's '56 Ford that had a new knife switch on the battery,
The boss thought they were a good idea.
We put disconnect switches on several cars. It was a mistake.
The expensive ones are better, the ones that are enclosed and cost over $20.
Put them at the ground end of the battery cable away from the battery.
Steve - Forgot to mention; I have my fuse located in the positive battery lead just before it reaches the terminal block. IIRC, John recommended to install it as close to the battery as possible.
After reading this thread again I must say that although the cheap ones with the knob on top are pretty fool-proof I have seen a couple fail at the beginning of a parade to the point where the owners had to remove them to get their 6 volt cars started.
I still like the enclosed kind that cost about $20 or more, but disconnects can be a pain in the a$$.
I have only one. It is on my '26 T. The starter button on the floor of a T is asking for trouble when you leave the car where others can climb in.
All my other cars don't need a battery disconnect.
When I worked for the big car collection we had a lot of trouble with burned out headlights before we went with battery disconnects.
We/they were removing the ground cable when finished with the car and nobody would bother to tighten them when they put the cables back on.
While driving the loose cable would break contact momentarily and the generator would go crazy for a moment and burn a light bulb or two out.
When we put disconnects on the cars we had no more bulb trouble.
The boss said he had trouble sleeping with more than five collector cars with their batteries still connected in a building housing over 200 cars.
I hope my replies are not taken as snide.
While it is true that a proper functioning electrical system be it a T or modern car should not need a master cut off, I like and use them for storage purposes---just as the original poster was asking, or when out parked in public to avoid theft or other dangerous acts by others. I have been using the kind with the green knob on top that goes onto the negative battery terminal (they are not designed for the positive terminal, the two terminals are different sizes--in case you did not know).
The only other kind I would use is the more spendy cut off as used by racers. They are usually available in a higher amp rating for heavy duty applications. I would not mess with a cheaper one--period. I had to run one of these under certain rules for NHRA drag racing. Although they wanted it on the positive side which I did not agree with but had to do. This one is rated 175 continuous Amps
I fully believe that these could have the potential to cause issues in vehicles as John and Ron posted above. But I am very particular to running wires and terminals correctly---no butt splices without soldering and no terminals without soldering, and I shrink wrap all of my connections. That being said, I have never had an issue I believe to paying attention to the details and will continue to use disconnect switches for storage only, or if parked out in public. As was also pointed out above, they are not a fuse, nor should they be thought of such--and in case of preventing a fire say while driving, it will not do that either. Once it is one fire, it's on fire. No cut off will stop that.
As far as where to put one, as the OP requested, you can try the green knob type and see if you like it on the battery or use the type like I posted below and sometimes you can fit them on the seat riser (vertical piece behind starter switch on floor). But either way, I personally would run it on the ground side.
(Message edited by Chad Marchees on December 07, 2014)
Conversiont ? OK General Nuisance... I spent 30+ years as a power plant (in the trades we call them generating stations, but didn't want to "offend" anyone) mechanical engineer and managed a fleet on General Electric 20MgW gas turbines. One site was black start (can I say that or will you be offended by that too?) and used a bank of 110 TWO VOLT CELLS to power a UPS unit that provided us with field current to initiate generation. That was in the event that our military failed us and we were hit with an EMP device and lost the field nation wide. Hmmm.
Each cell was 2500 lbs... do the math on the ampacity. YES <<<<<------ EVERYTHING was in sealed explosion proof devices, even the light switch on the wall. You related to that kid that threatened to infect this forum with viruses? The ganglion cyst thumpers beat me up for that one too. Shame you missed the show.
OK Gumpp... go change yer socks and enjoy your holidays. Merry whatever it is that people like you celebrate.
Now that thats' out of the way, Ill go do my penalty tours...
Nothing like a spark next to a gassing battery?
I'm sure that will be a consideration by the mouse that chews through the insulation on a stored car with battery connected.
Ronnie - I disconnect the ground strap on my T if it is going to be stored for any length of time. All of the people talking about troublesome disconnect switches have scared me off from installing one.
Disconnecting the battery is no different of a practice than shutting off the gas.
Re-read my two posts. Nowhere did I say I was "offended." I did say it was tiresome to watch people with legitimate questions come on here and be subjected to snide remarks and flip comments about their question - none of it particularly useful to them in solving their problem. Honestly, how helpful was your initial response to the guy's question about a battery cutoff switch?
I've been involved in this hobby for 40 years now and I have never before seen the likes of some attitudes towards people looking for information that I see with ever-increasing frequency on this Forum. I often wonder how many new Model T enthusiasts have become avid stamp collectors instead after receiving some of the "replies" that are on here at times.
You are so right, Ron. I agree 100%. You won't catch me asking any questions here.
Is it possible, if your T is left unattended in your driveway, grocery parking lot or car show, that a child or adult could move brake lever forward and step or push on starter button and move the car forward?
I let kids get up on my doodlebugs at shows - that is exactly why I have the battery kill switches on all of them.
My apologies for spouting off... been a bad few weeks around here with wifes surgery with several complications from anesthesia and pain meds collapsing her lungs, and with COPD and emphysema and unable to swallow even water it was several trips overnite to the ER. for dehydration etc. Each time was 8-10 1 liter bags of water . Maybe she needed a raw egg for the leaks LOL... etc. Personally Id disconnect the ground from the battery and not have your face over it. Batteries generate fumes when charging, more so that when sitting... Ignorance is bliss, when I was a kid I was checking dads 26 touring car batteries water with a zippo lighter and lucked out. If the clamp is good, 1/2 turn on the nut should loosen it enough to twist it off. Be careful... ws
A single fuse is not a good idea. If the fuse does blow when you are driving at night, you loose all power and all lights. That is why GM and VW have close to 50 fuses, avoids law suits.
I use a screw switch on the 14 with the alternator (which has leakage) and nothing on the coupe with the Ford generator (which has no leakage).
If a 25 amp fuse in the main power feed to the T needs to blow then you will lose more than lights if you don't have the fuse since your harness is cooking and you already don't have lights most likely. The fuse saves the wiring and prevents the car from burning up when there is a catastrophic failure in the cars wiring. I don't see how you could possibly be better off without it. The reason there are more fuses in a modern car is that there are different gauges of wire and lots more wiring. The lightest gauge of wire in a T is 16 and it can blow a 25 amp fuse fast enough unless there is no fuse to blow.
Ronnie, I agree with John F and Ron the Coilman. If you are willing to use a battery key to fix an electrical problem you will need to look and repair the problem before thinking about the key.
The 25amp fuse can be used as a battery key if it is put the right way in the yellow wire going to the battery terminal of the starter switch.
As you set your car for a long time just take out the fuse and you cut of the electricity from the car.
I you really want a battery key, go for one that can stand 1 1/2 times the maximum current. If your starter takes 400amp you will need a key that can stand 600amp. Don't go for the cheap plastic but take a solid more expensive one.
On the tractor rebuilds I am doing since 38 years I use the keys together with a heavy duty relay.
LOL some of the stuff I read on this forum!
If you are worried about a tiny spark igniting off gas on your battery, I suggest you learn about battery maintenance.
No well maintained battery will produce enough hydrogen to do ANYTHING in an open area large enough to house a T...
Tony I agree I have an "Old" knife blade disconnect on 3 of my 6 cars (the other three are not running) these are mounted to the frame and the ground connected to the switch about 3 feet from the battery plenty of room. It doesn't matter if your ground is positive or negative always connect to the ground!
I have a wing nut on the start button which I disconnect on long storage. I don't think this is the best but?
Apparently you have never witnessed a charging automobile battery explode when a careless workman removes the battery charger cables causing a spark? I have several times, it is not a pretty sight and very dangerous.
Ron the Coilman
Id recommend a nice hot lithium ion battery for that dirt bike motor on the bench... make sure you wash it down frequently with some salt water. Gotta keep it sparkling clean. Don't forget to always pile up the oily rags every nite too... right next to the gallon of acetone.
Coal dust explodes as easy as grain dust too.
I worked to recondition batteries and we only had one explode in the time I worked there. And it was because a new kid didn't top it off with acid.
And notice what you said, while charging. The gas is only produced while charging. If someone is hooking up a switch I doubt they are going to use it while the car is running or charging.
And again a well maintained battery in an open air environment does not pose the danger you are describing. But I am assigning a bit of responsibility to the owner YMMV...
Batteries also produce gas when being loaded, like using the starter.
Once you have had one explode in your face you will never let it happen again.
It has nothing to do with being in a tight garage or out in the open air.
You can not blink your eyes fast enough to protect them from a battery explosion.
PUT THE BATTERY SHUT OFF AT THE END OF THE CABLE AWAY FROM THE BATTERY. Put it where you can use it without uncovering the battery.
I wouldn't dare do this without being able to positively kill the starter button.
That's what the battery cut-off switch is for!
Mine is hidden under the driver's seat. -
Yes, they do wear out, so I figure on replacing it every five years or so.