12 Volt Alternator Conversion

[JSL - D24]

Does anyone have a ballpark range of how much it should cost to have a garage install a 12V alternator in a 1947 Dodge D24?

 

Parts and Labor.

 

Thanks.

[48mirage]

Ballpark $200.00, do it yourself probably less than $100.00.  This is assuming that the rest of the car is already set up for 12 volt.

[JSL - D24]

Thanks 48.

 

Rest of car is not set up for 12.

 

Converting from 6v with bad generator.

 

Any difference?

[DCurrent]

The alternator will probably be somewhere under $100 and labor for installing it probably an additional $150 with some modification to be done. Don't forget all the light bulbs will have to be changed (headlights, taillights, courtesy light, dash, back-up, park lights, hood ornament) along with the battery and sending unit in the gas tank. The solenoid for the starter may get you by for a while, but it is recommended that it's changed also. You will likely want a volt meter installed. Also you will want to disconnect your radio, clock, and heater until they are adapted for 12v by either a reducer, or a 12v compatible electrics.   

[P15-D24]

And don't forget the condition of your wiring. 

[steveplym]

Don't forget to have the runtz voltage reducer for the fuel gauge.  12 volts will damage you gauge. 

[knuckleharley]

 Don't forget all the light bulbs will have to be changed (headlights, taillights, courtesy light, dash, back-up, park lights, hood ornament) along with the battery and sending unit in the gas tank.   

Huh? How does the sending unit know what the voltage is? It's nothing more than a lever that moves up and down.

[james curl]

If still running the wide belt you will need a new wide pulley for the alternator.  Said pulley can be bought from Speedway I believe.

[wayfarer]

If you already have some kind of 'bolt-on' kit then perhaps an hour of shop time ($100) will suffice. However, if you are expecting the shop guy to design and fabricate the mounting hardware you will be spending considerably more, even if the shop rate is less.

An alternator can be had from most pik-a-part yards for $20 or so and you get to choose what will work best for your change.

Also, making the connection to the wiring harness and possibly adding an electronic regulator will add even more even if your wiring is in great condition. If the condition of your wiring is at all suspect then perhaps you need to rethink the project.

[DCurrent]

Huh? How does the sending unit know what the voltage is? It's nothing more than a lever that moves up and down.

I meant the fuel gauge. 

[Scruffy49]

Spend the extra money up front on a new wiring harness if yours is at ALL on the suspect side. You'll get real fused/relayed circuits, brand new modern labelled every 5-6 inches wires, a good installation guide... And everything you need to add a GM alternator from the 1970s. For vehicles like ours, the 12 circuit kit is more than sufficient. You can keep all your old switches, or convert them to GM at the same time (easier to wire in, easier to replace). Change your starter solenoid/ignition relay to a Ford truck unit, 73-86 or so F series work best, but a Ranger unit is easier to hide. A $10 ignition switch from NAPA will bypass the factory push button if your car is so equipped.

 

I've rewired dozens of 30s through early 70s vehicles. It is worth the extra couple hours and couple hundred dollars.

 

You should be able to adapt the alternator bracket off a 292 or 302 GM straight 6 to your engine. Make a tracing of what you have, and hit the local pull your own part junkyard. Bracket should be $5-10 out the door. Or modifying yours is as simple as all thread, a few spacers and bending the tensioner arm (I prefer to replace that with heim joint equipped turnbuckles).