Technical 1951 Merc 6v-12v conversion

So my wires are falling apart and decided to swap to 12v negative ground - I had the generator converted to 12v - WHAT ELSE DO I NEED to make everything run correct - starter ? Do I need that converted ? Isn’t that wired 6v positive negative? I’m new and looking for help - 12 coil with built in resistor ? I know I need new bulbs and headlights - and resistors on gauges - ANYONE have a list of parts -

 

12 volt regulator.
Starter is OK as is.

 

So wire starter to 12 v regulator then to positive side of battery ?

 

No. He means replace your current 6v regulator (on the firewall usually) with a 12 volt regulator.

 

Replace this with 12v

 

Oh, for the gauges, there’s a few ways to go. A Runtz reducer. A reducer from Dodge or Ford up through the late 70’s (they both used 6 v gauges) or you can search for a voltage regulator circuit and build your own.

 

That’s your solenoid. It should be changed to a 12 volt one as well. I did anyways.

 

Bought this to wire in also !

 

Regulator will be a rectangular box with 3? As I recall wires to it.

 

That’s a voltage regulator

 

Oh. If you have a heater, some have said they run theirs on 12 volts. I’d look for a different blower motor though. Last thing would be (that I can think of) if you have a radio. It won’t take kindly to 12 volts.

 

So the starter is fine - wire the car like I would a 12 volt -

 

One other thing, do you have an overdrive on the transmission? You’ll have to look into what to do about its solenoid if so.

 

Yes but none of that is hooked up -

 

Also remember now that you’re changing to negative ground, the original ground cable and positive cable at the battery will be swapped, you’ll see the ends that bolt on the battery don’t work so well unless you change cables

Also, are you sure you don’t need a ballast resistor for the run side of the key?

 

Yes ones big and ones small

 

Check my last edit. Ie ballast resistor.

 

When I did this on 53. The list-
1. All 6V bulbs. 2. Voltage Regulator 3. Horn Relay 4. Starter Solenoid 5. Radio if equipped.
6. Power to gauges- use a FORD gauge voltage reducer- used by them into the 70s. Only need one to supply all the gauges. Tie in at the gauge supply junction which then "daisy chains" to all appropriate gauges. Make sure the mounting screw is grounded.
7. If you have an ammeter- look at the back of it. Mercury and Ford went to an inductance type sometime in that period. If the back of the gauge has a double hoop with the wire going through it, it is that type. You will have to reverse the wire direction when you change from positive to negative ground.
8. Circuit breakers- not sure about 51, but there should be a couple under the dash. Check to see if they are rated for 12V.
9. As previously stated, the starter and horns should handle 12V just fine. The heater motor should also with limited use. If you plan on winter driving, I would go to a 12V motor.

 

If you had your generator converted to 12 volt that's the wrong regulator, it's for a 60's GM alternator. You probably want a Standard Ignition VR35. Replace the starter solenoid with a SS587.

 

Lot's of good info here. I'm not looking to thread jack but I am in a similar situation and there is no point in starting a new thread. Mine has already been converted to 12v but remains positive ground. Assuming all of the work has been done correctly should it be as simple as swapping the battery cables? The previous owner told tells me he had the generator converted to 12v and that he used a resistor to protect the gauges. I don't think he did much more than that. The heater and horn act like they are getting 12v but should be 6v. The heater fan runs at 900 mph and the horn sounds like a civic on steroids.