1955 Battery for 12v Conversion

[66ford]

What size battery would be best for a12 volt conversion in the Midwest. Car is basically only driven in the summer

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[83ragtop50]

I have a '55 that has been converted to 12v. It appears that it has the original 6v style battery tray and hold down clamp. A group 55 battery fits just fine. In fact I just purchased a group 51 from Walmart for $159.99 with a 3 year warranty. The group 51R batteries are the same size but the locations of the positive and negative posts are swapped end-for-end from that of the group 51 style. Group 51R batteries are sold by more places. I hope that this helps.

 

[SHA BOP]

I have a 55 6 volt and I do not understand the logic to change to 12 volt. I use the Optima 6 volt 800 CCA (same as many 12 volt batts) and fits in the old facade black battery case to look original.
In addition, I installed a 6 volt alternate that has the same appearance as the old generator. It charges 7 volts at idle as well as cruise. I made this upgrade about 5 years ago. In addition, I changed tail lights, turn signals, etc bulbs to LED. I bought the car in 1987 as second owner. I feel strongly about keeping it original as I can.

 

[Boah1959]

1955 T Bird

Not sure if I should be posting this in this thread, but I’ve completed a full 6V to 12V conversion using parts(Kit) from Vintage Auto Garage. Everything was set up and running fine until the key tumbler broke, so I had to replace it. (4 times it started while on lift)

I removed the switch mechanism and replaced the tumbler, then reassembled everything. Now the car won’t start. It cranks, and it seems like there’s voltage coming from the coil.

I believe is the correct hookup at the ignition switch (excluding accessories). Can someone confirm if this wiring is correct?

A side note , In respect to 6 V versus 12 V I was a strong believer of staying stock. I have been struggling for three years going to various specialty shops, I upgraded wiring system new battery etc and none of them could actually get this thing to turn over consistently, My wife is tired of pushing the car to the side of the road.😜 so it’s was time to make the change.
Marty

 

[Tom Alpers]

Since all was good till the ignition switch/tumbler caused a problem I would buy a new ignitions switch. You can put the new tumbler into the new switch.

 

[Boah1959]

Since all was good till the ignition switch/tumbler caused a problem I would buy a new ignitions switch. You can put the new tumbler into the new switch.

I thought of that as well. I will purchase one tomorrow. Does the wiring diagram look correct (simple as it is) less accessories.
Thank you for your quick response as well.

 

[Tom Alpers]

I thought of that as well. I will purchase one tomorrow. Does the wiring diagram look correct (simple as it is) less accessories.
Thank you for your quick response as well.

To be honest, that is the worst wiring diagram I've ever seen. Since you have switched from the 55 6 volt to 12 volt it's difficult to give advise on the wiring because we have no idea how whoever supplied the kit set it up and what parts they used. Was it also changed to negative ground? The 55 didn't use a balast resistor and the 12 volt setups do. Does your new setup have the ballast resistor along with the proper solenoid to apply full 12v during crank?

 

[Boah1959]

To be honest, that is the worst wiring diagram I've ever seen. Since you have switched from the 55 6 volt to 12 volt it's difficult to give advise on the wiring because we have no idea how whoever supplied the kit set it up and what parts they used. Was it also changed to negative ground? The 55 didn't use a balast resistor and the 12 volt setups do. Does your new setup have the ballast resistor along with the proper solenoid to apply full 12v during crank?

 

[Boah1959]

Thank you for your help
Yes I agree on the drawing I am no engineer that is for sure. I have a detailed cad overall wire diagram, but I was trying to simplify it for a quick fix and comparison. Before I tock the switch off it worked then when I put it back it turned but no ignition, so I thought maybe I wired incorrectly.
Vintage Auto Garage 12V conversion kit for the 1955 Ford Thunderbird does not require a ballast resistor

• SW3-RL03-is a matching 12 Volt solenoid

The other components

• CE-1500 12V Ignition Coil → this has an internal resistor
• MGR1 voltage reducer → drops voltage for factory gauges (fuel, temp, oil)
• alternator (82155-2) → has a internally regulated
Marty

 

[SHA BOP]

1955 T Bird

Not sure if I should be posting this in this thread, but I’ve completed a full 6V to 12V conversion using parts(Kit) from Vintage Auto Garage. Everything was set up and running fine until the key tumbler broke, so I had to replace it. (4 times it started while on lift)

I removed the switch mechanism and replaced the tumbler, then reassembled everything. Now the car won’t start. It cranks, and it seems like there’s voltage coming from the coil.

I believe is the correct hookup at the ignition switch (excluding accessories). Can someone confirm if this wiring is correct?

A side note , In respect to 6 V versus 12 V I was a strong believer of staying stock. I have been struggling for three years going to various specialty shops, I upgraded wiring system new battery etc and none of them could actually get this thing to turn over consistently, My wife is tired of pushing the car to the side of the road.😜 so it’s was time to make the change.
Marty

1955 T Bird

Not sure if I should be posting this in this thread, but I’ve completed a full 6V to 12V conversion using parts(Kit) from Vintage Auto Garage. Everything was set up and running fine until the key tumbler broke, so I had to replace it. (4 times it started while on lift)

I removed the switch mechanism and replaced the tumbler, then reassembled everything. Now the car won’t start. It cranks, and it seems like there’s voltage coming from the coil.

I believe is the correct hookup at the ignition switch (excluding accessories). Can someone confirm if this wiring is correct?

A side note , In respect to 6 V versus 12 V I was a strong believer of staying stock. I have been struggling for three years going to various specialty shops, I upgraded wiring system new battery etc and none of them could actually get this thing to turn over consistently, My wife is tired of pushing the car to the side of the road.😜 so it’s was time to make the change.
Marty

To make sure the battery stays topped up, keep it on a trickle charger while in the garage and don't forget to add a battery cut off switch at the battery. This will eliminate many problems

 

[Tom Alpers]

Do you know how to "hot wire" a car? I would "hot wire" it and see if it runs. That would eliminate the ignition switch from the circuit. Be sure it's in PARK or if a manual in neutral with parking brake on.
I looked at the kit you installed and don't see any ballast resistor listed. I'd have to assume they picked a coil that doesn't need the ballast. Does the coil they supplied have a brand and part number on it?

 

[SHA BOP]

It is very simple to bypass the ignition switch without any "hot wiring". I bought a simple switch with two alligator clamps and start button from Casco. Connects to start solenoid. You can start engine or bump the start button to slowly rotate the engine for static timing or valve adjustments. My bird is still 6 volt and not sure what happened to your key switch when changed to 12V.

 

[Tom Alpers]

It is very simple to bypass the ignition switch without any "hot wiring". I bought a simple switch with two alligator clamps and start button from Casco. Connects to start solenoid. You can start engine or bump the start button to slowly rotate the engine for static timing or valve adjustments. My bird is still 6 volt and not sure what happened to your key switch when changed to 12V.

What you just described is half of what is colloquially called "hot wiring". Hot wiring includes a wire from the battery to the coil so that when you push the 'button' and crank it the engine will start and run.