Jump to content

how does this work?


truth
 Share

Recommended Posts

i included photos of the switch in question  it is right beside another switch on my 1918 fiat switch that is a bosch dual coil switch     the bosch dual coil  switch allows you to start on battery then switch to magneto  the switch in question though  is the 5 pictures   as you can see it only has one wire out the back    yet the switch has 2 positions?   i believe the one wire will work only when there is a ground    since it is a wood dash   i think the ground is attached to one of the 3 monting screws[one hole is tapped w threads]  so i understand how one function can occur through this switch.  my confusion is why the 2 different selections and whats it for?  some kid ripped all the wiring out this car and im trying my best to figure it out!  i know there is an answer out there    can anyone help me?   theres a #1in the center   then a # 2 on either side  then a #3 on the handle  in the center above the #1 is stamped "dual"   the very top on the curve is a  riveted plate that says bosch    post-154063-0-28303700-1454989573_thumb.post-154063-0-30000200-1454989607_thumb.post-154063-0-91830100-1454989679_thumb.post-154063-0-47631500-1454989704_thumb.post-154063-0-59165500-1454989728_thumb.

Link to comment
Share on other sites

One thing to do is to check what has continuity and what doesn't for each switch position.  The screws on the back just look like housing retention even though the spacing is odd.  But go ahead and probe those in the different switch positions and not just to the terminal but to each other and the case.

Link to comment
Share on other sites

i will do continuity when i get home tonite ive done it once and all it does is one function    on and off     the #2 positions are the same but i will check some more    i like the idea of magneto cut off cause how else would the car turn off?   i guess you could flip to either of the 2,s to turn off?i think the lights are on push button switches some of the wires are there for some of the lights    the stamp of dual kinda makes me think its related to the ignition system    its new to me though that you can flip 1 switch to 2 different positions and it does the same thing why would fiat do that?  thanks for your comments  ill post definite continuity results

Link to comment
Share on other sites

Put Bosch dual magneto switch in your search engine and some interesting images are available very similar to yours.  It appears the left 2 should be a 0.

 

This is a link to a pdf that came up on the search, which should help you and it does look like the screws are terminals.

restorecarsclassifieds.com/wiki/show_pdf.pdf?n=379

Link to comment
Share on other sites

I had a chance to study the pdf and the top diagram look very appropriate for your switch.  Left is off, center is one set of plugs and right is both sets of plugs.  Looking at the back of your switch there are faint circular marks on the same diameter as the 3 screws.  Missing terminals?  Probably time to ease the cover off the back.

Edited by emjay (see edit history)
Link to comment
Share on other sites

This switch is peculiar to 2 spark dual Bosch magnetos. 2 position ( both left end and right) is for both sets of spark plugs in operation, 1 position is for just one set, use this for starting then switch to 2. Why Bosch made this a 3 position switch is beyond me!

 

 

Link to comment
Share on other sites

wow yall are great! alot of info that ive been starving for   thank you    ive got to digest this  it sounds like both sets of plugs may be used at same time?  i thought one set was for start on battery then switch to magneto[which is done w the bosch dual coil switch not this switch] but im starting to think theres more to it     i took the switch apart and did continuity   all the #2,s do on the switch is interupt    the signal     the signal  goes through switch in # 1 position[the brass button is the wire connection on the back side          you can see where the switch travels by the skidmarks in the bakelite non conductive material] ill post again once i wrap my little brain around all this    and thanks again

post-154063-0-44855300-1455073819_thumb.

post-154063-0-65980100-1455073837_thumb.

post-154063-0-36690900-1455073856_thumb.

Link to comment
Share on other sites

It's hard when someone removes parts that would help you sort the system out. Is there evidence of a glass jar battery mounted on dash or under the passenger seat? That may be independent of the electrical system and the charge maintained by a charging plug connected to a charger in the owner's garage. That would be the power for starting on the coil ignition. Once started the switch would be positioned to turn off the coils and their plugs, then switch to the magneto. I wouldn't expect it to run on the coil and mag concurrently. Sometimes you just have to mount the pieces in place, start with what you do know and build on that.

I am not familiar with the Fiat. Does it use a generator or flywheel mounted dynamo? Is there an oil filled switch with a mushroom foot pedal to start? Two 12V batteries in series?

I am being reminded of a 1913 Rambler that I sorted out electrically about 20 years ago. And wondering if you have taken a look at electrics on some of the early Rolls-Royce small horsepower cars. You might get some answers there.

Bernie

Edited by 60FlatTop (see edit history)
Link to comment
Share on other sites

this 1918 fiat touring has a 6 volt battery on the running board    its housed in what looks like a big tool box    theres 2 holes drilled in running board apron for cables to go through   im thinking[and yall can correct me ] that the switch in question stays in #1 position when car is not running   this grounds out primary circuit to points for the mag    when you start car the bosch dual coil switch is in battery and start selections       once it starts you put those switches into mag and run positions then flip switch in question to one of the 2 positions labeled#2 this stops the primary circuit being grounded and now all 8 spark plugs are firing in all 4 cylinders[ 2 per cyl]  im still not sure how to shut it down cause the battery and coil will still be on after the switch in question goes back to ground[ or position#1]  maybe the off on the other switch is when the selection is in center between batt and mag   if thats true i may have arrived w everyones help    im getting closer thats for sure   and seeing lite    oh this does have a generator  but im thinking of just keeping a small tender on it and not using the generator cause of other issues   and im pretty sure its positive ground   i think once the bosch coil switch is put on mag and run selections that this turns off the coil   so  starting to make some sense of it i think for now

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...