Help with 12v Conversion

Kaonix

Kaonix

Member
Hi guys/girls,

New member looking for some help. We have a 41 Deluxe with the original flathead. I'm converting it to 12volt and have everything complete but am having trouble with one thing. The starter button. The car has the standard starter relay with three terminals. One large from battery+ one large to starter+ and one small terminal with what I think is the wire from the starter button. If I manually jump 12+ to the small terminal, the starter cranks normally, however I cannot get it to crank with the starter button. I have + to the ignition switch, however the starter button has only one wire going to it and it has no voltage. Where does this button get voltage from to trip the starter relay? Can anyone help me out with this? If you need any further information to help please feel free to respond or pm or email.
 
i used the original 6 volt 3 term solenoid,the starter button just grounds the wire when you push it,check to see if its making a ground
 
Its making ground. Where does this wire get 12+ from tho? I also used the original 3 term solenoid, as well as the original ignition switch but this wire has no voltage and I have no idea where it gets the voltage from to switch the starter relay.
 
The original solenoid worked by grounding the small terminal with the starter button (to the dash).
It sounds like you have replaced the solenoid with a 12V item which requires a live to the small terminal.

I believe you can get a 12V solenoid that uses a grounded pin like the original, but I don't know the part number. It has been mentioned on this forum before though.
Two alternatives:
1, use the 6V solenoid. It will last ok as long as the engine starts pretty readily.
2, rig up a relay to supply 12V to your solenoid when you earth the starter button.

Actually there is another solution. Use a different starter button that has two connections and sends a live signal to the solenoid.

Or another one - use an ignition switch with a keyed start and do away with the starter button.

Mart.
 
maybe the solinoid is not grounded,try a jumper from neg to one bolt holding the solinoid and try it,try grounding the small term on solinoid also the wire to the button is only a ground, you may hve a broken wire between solinoid and button or a bad solinoid
 
Only one of the large terminals is internally connected to the relay coil. The hot side of the battery has to be connected to the correct large terminal for the ground terminal to inergize the coil properly.
 
I haven't changed the solenoid. The car was 6volts when we got it so I should be safe in assuming the solenoid is the 6volt version. The only thing I changed on the car was to change from positive to negative ground. Is there any way without changing the button to make this button work?
 
I think it will start ok but your coil will need to be changed and 12 volt neg grd,and anything you may have trouble with.
 
If you have only changed from 6V to 12V and neg to pos earth, the solenoid should work.

If the solenoid does not pull in when you EARTH the small terminal there is a problem with the solenoid.

UNLESS you have swapped the positions of the starter and battery cables on the solenoid. (as stated above)

Make sure the cables are on the right way round and firstly see of the solenoid will crank the engine if you push the button underneath the solenoid(mechanically activate it).

If it does then check if it pulls in if you earth the small terminal.

If it does then see if it pulls in when you earth it through the starter button.

Just follow a logical process and it should be pretty easy to see what is happening.

Mart.
 
rotorwrench said:
Only one of the large terminals is internally connected to the relay coil. The hot side of the battery has to be connected to the correct large terminal for the ground terminal to inergize the coil properly.
Click to expand...

PROBLEM SOLVED! rotorwrench you were exactly correct. Switched the big terminals and she cranked over just like before but with a helluva lot more 12v punch! Thank you SO MUCH!
 
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If it's the one wire LUNGE button, add an on/off switch between that wire. Real problem solved:D

With a one wire "Lunge" button if the vehicle is left in gear and should that button be pushed, the starter will engage, the engine will turn and that will make the vehicle lunge and start moving:eek:

I only know this due to alot of reading. Bill Sinclair's Thunder Road electrical guide goes into this in detail on pg's 93 & 94, a great reference. Randy Rundle's "the official 12-volt conversion guide" and Jack Sweeden's "how to wire your streetrod" are other good book's. Scott
 
Check continuity between the terminal for the starter wire and the small terminal. If they are connected (there will be resistance) the solenoid is wired backwards. The one wire button provides the ground path. But since you can jump the battery side to the small term and start it. I think you have a different type solenoid. You need a 2 terminal button for it. You will need to run one more wire from the bat term to get it working.

I just re-read post 10. Exactly! Nice easy fix.
 
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When I converted our 47 Merc to 12 v, I had to go from a wire start button,
to a 2 wire. I think I bought it a Bob Drakes.

Bob
 
Those 2 wire bottons are getting hard to find,maybe a tractor place has them.Had a guy looking for one the other day.
What I did was in place of botton put a key start switch,Its a better switch then orginial.
 
I just converted mine to 12 volts and left the old solenoid with the starter button on the dash. I hid a toggle switch under the dash that breaks the wire from the solenoid to the button so that I could disable the button when I'm parked to prevent a dangerous situation. I also wired the ignition wire into the same toggle switch so that is controlled by the switch as well.
 
Randy said:
I just converted mine to 12 volts and left the old solenoid with the starter button on the dash. I hid a toggle switch under the dash that breaks the wire from the solenoid to the button so that I could disable the button when I'm parked to prevent a dangerous situation. I also wired the ignition wire into the same toggle switch so that is controlled by the switch as well.
Click to expand...
That's it Randy:D Hope it spreads like a cold. After all these years people still don't realize this hazzard when they buy an old Ford. Scott
 
39portlander said:
That's it Randy:D Hope it spreads like a cold. After all these years people still don't realize this hazzard when they buy an old Ford. Scott
Click to expand...

This is why I try to read every post, even if the original subject isn't of interest to me. Never thought about the LUNGE factor.
 
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