I need a new ignition switch for the ol Merc. It's a 51 and dosen't have a start position. I'd like one with off, on, and acc. I'm wiring it with the starter push*****on. Where can I find one. Also, how do ya wire one of these in? Do you just interupt the starter circut? Thanks.
Pushbutton is a grounding point for tghe solenoid on the firewall--it has asingle wire and just grounds that to the dash. If not running the flathead, one of several possible tricks is needed to make the modern stuff work with a pushbutton. What are you putting together here??
I have one in my 54 that I bought from the local parts store that is actually I think for a lawnmower but its a nice looking unit with nurled looking outer ring on it so it doesn't look*****py. Some parts stores sell them as universal ignition switches. The way my switch is wired there is several poles on the back of the switch and they are labeled batt., ign, acc, etc.. I have a hot wire from the battery to the battery side of my switch then a wire from the ign side of the switch that runs to the distributor. I have an hei ignition in my 54 so I don't have a ballast resistor but if your engine has points you'll need to run the ign wire from the switch to one side of the ballast resistor then another wire from the other side of the ballast resistor to the distributor. On a points distributor in a gm engine you also have to run a wire from the non start side of the starter solenoid to the ballast resistor on the side with the wire running to the distributor I think if I remember correctly. That way when you are turning the engine over it has power while it is spinning because if you don't do that they won't start untill you let off of the key if they start at all. Ok next run your hot wires for your radio and all your accesories to the acc side of the switch. Then I lastly ran a wire from the start side of the switch to the start side of the solenoid on my starter. Oh yea if where your switch is isn't grounded like on a wooden dash or fiberglass dash you will need to make a ground wire for it other wise it won't work right. And make sure you unhook the battery before doing all that or you might burn the damn thing up like a friend of mine did a couple of years ago. Clear as Mud? This may not be the route you want to take but I bought my switch for like 10 or 12 bucks I think and it came with two sets of keys so I was happy.
Mine came from a local parts store, and I see that Wal Mart sells thexact same one (Cal Trem brand). It was like six bucks and has an accessory and a start position. It's also easy to wire, as all posts on the back are clearly labeled. Fits perfect and looks great in my 49 Chevy...
Wiring a push*****on is pretty easy. You have two choices - use it as hot, or ground; although I've always wired them hot. Run hot from your ignition switch to the starter*****on. Run a wire from the other terminal of the*****on to the solenoid. If you want to get fancy, you can put in a small fuse panel that is fed from the hot side of the ingition switch. That panel can power up your coil, electric fuel pump (if you have one), start*****on, etc... Make sure to get a "momentary on" switch (usually marked like (on) on the packaging. Tackett
49 - 51 Merc start*****ons had only one wire connection. They work only by going to ground. There are other 2 pole switches available though that are identical in appaerance, Can;t tell ya where to get them though - sorry.
If '49-51 Merc starter*****ons are the same as '49-50 Ford, and I think they are...you can carefully take the bezel off of the original starter*****on. Use a new 12V starter*****on with two posts, put it in the dash, and silicon the old bezel over the retaining nut that came with the new*****on. Most parts houses (O'Reilly's, Napa, etc....mine came from Carquest) carry the*****on in a couple different sizes. Get the one closest to the size of the stock*****on so it will fit through the bezel. It pays to take the old*****on apart and carry it with you to the parts store. Use this with a cheap 3 position ignition switch like the one kustomd described...and there you go, stock looks with modern 12V function.
I'm not familliar with the Buick starter/solenoid system, but if it's like a Chevy, I used a horn relay (small and cheap). The old Ford starter*****on works like a horn*****on to ground the horn relay sending juice through the other 2 terminals down to the chevy solenoid to energize it. You could use a Ford solenoid but they are big and ugly. A horn relay will carry some serious amperage. I didn't want the heavy wire running up to the dash and back down. Just my preference.
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