how to wire the ignition switch?

[harmony]

I'm about to wire in the ignition switch for my run engine stand. (1946 Chrysler) I have the original start button and ignition switch.  One side of the start button will go to the small post on the starter solenoid.  (The post right above the battery lead terminal) That much I know.  I'll mention the other side of the start button switch at the end.

The ignition switch has 3 posts. ( one long and 2 shorter ones)  The tall one has two markings beside it.  RAD & GA.  One short post has COIL marked beside it and the other short one has AM marked beside it.   I suspect a wire will go from the AM post on the ignition switch to the Ammeter, right?  I also suspect a wire will go from the negative side of the coil to the ignition switch post marked COIL. Right?

So this leaves the long post.  I'm just wiring up the engine, and fluid drive, nothing else.  So that included the generator, starter solenoid, regulator, trans relay, governor, interrupter switch, solenoid (on transmission), kickdown and anti-stall on the carb. 

 

According to the wiring diagram, coming off that long post on the ignition switch is a wire going to back up light (Doesn't apply).  A wire going to the turn signal assembly (doesn't apply).  A wire going to the horn relay ( doesn't apply). A wire going to  the fuel gauge ( doesn't apply).   However when I follow the other wire coming off the start button ( as opposed to the wire I mentioned at the beginning) it goes to the fuel gauge and then back to the ignition switch.  In the diagram it looks like it's going to the long post. 

Since I'm not connecting the fuel gauge to a tank, should I run the wire from the start button directly to the long post on the ignition switch?  I'm using the entire stock gauge cluster on my run engine stand, so I could run wires through the fuel gauge if necessary, but it's not connected to a sender unit, since I'm not using a conventional gas tank, so it seems unnecessary to me. 

Btw, what does RAD & GA mean?

[MarcDeSoto]

I don't know what RAD and GA means either, but if you are just trying to start the engine, why not just hot wire it?  All i did was connect the battery cables.  Connect a remote starter, or your push button from the Neg. battery post to the upper right terminal on the solenoid.  Connect the points terminal outside the dist. to the POS side of the coil with a jumper wire.  Then connect the NEG battery post to the NEG post on the coil with a jumper wire.  Now your ignition is hot.  Then crank it and it should start if everything else is ready, timing, carburetor, etc.  

[harmony]

36 minutes ago, MarcDeSoto said:

I don't know what RAD and GA means either, but if you are just trying to start the engine, why not just hot wire it?  All i did was connect the battery cables.  Connect a remote starter, or your push button from the Neg. battery post to the upper right terminal on the solenoid.  Connect the points terminal outside the dist. to the POS side of the coil with a jumper wire.  Then connect the NEG battery post to the NEG post on the coil with a jumper wire.  Now your ignition is hot.  Then crank it and it should start if everything else is ready, timing, carburetor, etc.  

My objective is to wire it completely as it would be as if it was in a car, and check all the circuits and make sure it's all functional.  I haven't quite figured out how I'll operate the fluid drive and shift the gears, just yet. 

 

Not many people besides the post war Mopar enthusiasts are familiar with the process of all the functions of all the components that make up the entire package that makes the car go down the road.  I think that Chrysler post war technology is pretty complex for its time, the way the Governor, Transmission Solenoid, and Interrupter Switch perform their duties in conjunction with the Trans Relay, and how the electrical side of the Carburetor plays a part in all that.

  

I also have my 1930 Hudson flathead straight eight engine and transmission, that I intend to do the same to.  The run engine stand is built for that and I'm just keeping an eye open for a reasonably priced vintage radiator for it.  That engine was rebuilt in 2004, but hasn't been fired up since then, so that should be an interesting project once I'm done playing with this 251.

 

The  car club that I'm a member of is trying to encourage me to have them both up and running and on display at our annual car show this August.  I guess I'd better line up a couple mufflers as well.  

[MarcDeSoto]

It sure sounds like you are barking up the wrong tree here.  If you want to have everything wired and working like the engine was in the chassis, why not put it in the chassis?  You can't check your trans. controls with the engine outside of the chassis, can you?

[D35 Torpedo]

I'm going to guess radio and gauges

[Sam Buchanan]

6 hours ago, harmony said:

The  car club that I'm a member of is trying to encourage me to have them both up and running and on display at our annual car show this August.  I guess I'd better line up a couple mufflers as well.  

 

Mufflers?! You don't need no stinkin' mufflers....let those flatties bark, the car show crowd will love it.  ?

[desoto1939]

13 hours ago, harmony said:

I'm about to wire in the ignition switch for my run engine stand. (1946 Chrysler) I have the original start button and ignition switch.  One side of the start button will go to the small post on the starter solenoid.  (The post right above the battery lead terminal) That much I know.  I'll mention the other side of the start button switch at the end.

The ignition switch has 3 posts. ( one long and 2 shorter ones)  The tall one has two markings beside it.  RAD & GA.  One short post has COIL marked beside it and the other short one has AM marked beside it.   I suspect a wire will go from the AM post on the ignition switch to the Ammeter, right?  I also suspect a wire will go from the negative side of the coil to the ignition switch post marked COIL. Right?

So this leaves the long post.  I'm just wiring up the engine, and fluid drive, nothing else.  So that included the generator, starter solenoid, regulator, trans relay, governor, interrupter switch, solenoid (on transmission), kickdown and anti-stall on the carb. 

 

According to the wiring diagram, coming off that long post on the ignition switch is a wire going to back up light (Doesn't apply).  A wire going to the turn signal assembly (doesn't apply).  A wire going to the horn relay ( doesn't apply). A wire going to  the fuel gauge ( doesn't apply).   However when I follow the other wire coming off the start button ( as opposed to the wire I mentioned at the beginning) it goes to the fuel gauge and then back to the ignition switch.  In the diagram it looks like it's going to the long post. 

Since I'm not connecting the fuel gauge to a tank, should I run the wire from the start button directly to the long post on the ignition switch?  I'm using the entire stock gauge cluster on my run engine stand, so I could run wires through the fuel gauge if necessary, but it's not connected to a sender unit, since I'm not using a conventional gas tank, so it seems unnecessary to me. 

Btw, what does RAD & GA mean?

Harmoney: If you have a service manual for your car, and you should, then go to the page inthe manual that shows the wire harness and the routing of the wires. Then you will know what the RAD and GA posts are used ofr and the wire that connects to these to posts.

 

Agin get a service manual, part of the basic manuals that should should always have on your car or truck.  These tell you alot about your vehicle.  I am not trying to be a wise guy, but people ask alot of questions that can be answered just by taking sometime to look in the service manual.

 

Rich

[harmony]

41 minutes ago, desoto1939 said:

Harmoney: If you have a service manual for your car, and you should, then go to the page inthe manual that shows the wire harness and the routing of the wires. Then you will know what the RAD and GA posts are used ofr and the wire that connects to these to posts.

 

Agin get a service manual, part of the basic manuals that should should always have on your car or truck.  These tell you alot about your vehicle.  I am not trying to be a wise guy, but people ask alot of questions that can be answered just by taking sometime to look in the service manual.

 

Rich

In my second paragraph, I've mentioned the wiring coming off the ignition switch in the wiring diagram.  Which is in the service manual, which is well used as the dirty pages will indicate.  There is no mention in the manual as to the actual ignition switch, and no mention of which post is which on that switch.  The posts do form a pattern of a triangle when illustrated, that "could" match the orientation of the actual switch.   When operating the key and using a multi-meter, I do get continuity that supports the flow of current to indicate that the wires would be going to the switch such as I indicated in the first paragraph. 

I'm hoping to get confirmation on that ( i.e. my thoughts on bypassing the fuel gauge)  as well as learn what RAD and GA mean, which is not mentioned in the service manual. 

Edited March 12, 2023 by harmony

[Tom Skinner]

I'm with D35Torpedo GA I think stand for Fuel Gauge. Rad is most probably Radio. I am refering to a colored 1946,1947,1948 Chrysler C-38 and C-39 Plastic Laminated Wiring Diagram By John Anastasio that was popular off of ebay 10 years ago. Basically its the same as our Service Manual Page 102. No other mention of RAD in adjacent Diagrams for C-37, or C-40 in our Service Manual. Makes sense to me that it is most likely Radio. Caveat Emptor: I am not a good Electrician. LOL

Good Luck!

[Dave72dt]

If your "other wire " from the starter button goes to the same terminal on the fuel gauge, then yes, you can run it directly to the key switch.

 

 

Wiring diagram I found does show that "other wire" on the same terminal on the fuel gauge.   

Edited March 12, 2023 by Dave72dt
added info

[keithb7]

I suggest hooking up a digital multimeter. Set to continuity. One end at main input power lug. Then check continuity at each of the output lugs. Begin with the key in the fully off position. See if any output lugs are getting power full time. Maybe glove box light, depending how the car is wired.  Cycle the key to the power-on auxiliary position. Now what lugs are getting power? Usually the radio and gauges in this position. Turn the key to the engine run mode, the position where the starter is engaged. Now the lug that goes to the starter relay is likely powered. Create an illustration. Label what lugs get power when. Compare it to the shop manual schematic. You'll have a full understanding by now and likely it'll all easily make sense.

Edited March 12, 2023 by keithb7

[MarcDeSoto]

I looked at a 49 DeSoto wiring diagram, and it shows the radio in the schematic, and the ignition switch does have a wire going to the radio.  So RAD does mean radio and GA does mean fuel gauge.  If you are wiring the car just the way it is when the engine is in the car, it's a bit tricky as the starter wire goes to the from the ign. switch to the horn relay, and the horn relay has a wire going to the starter.