Making and old speedo work in new truck/car

How do you guys do it? I'm swapping an old dash in my car, everything interior wise is going to have the retro / oldschool feel. So what do you guys do to make the old speedometer work with your set up?

id like some info on this as well.... a bunch of the older stuff( depending on how old obviously) are 6volt systems.

For the 6 volt to 12 volt conversion you need to change out the bulbs (an obvious one, I know) and set up resistors for it, but you will also need to know the amperage or wattage of everything you want to use with it. In case you're not electrical savvy (like myself) J.C. Whitney sells a couple types of converters. They don't say what they are, but I'm sure they're just resistors in a case. And even a few gauges have known to not be affected by swapping from 6 to 12V positive ground.

Originally posted by starion88esir



For the 6 volt to 12 volt conversion you need to change out the bulbs (an obvious one, I know) and set up resistors for it, but you will also need to know the amperage or wattage of everything you want to use with it. In case you're not electrical savvy (like myself) J.C. Whitney sells a couple types of converters. They don't say what they are, but I'm sure they're just resistors in a case. And even a few gauges have known to not be affected by swapping from 6 to 12V positive ground.

yeah the bulbs will just burn twice as bright. I dont think that is their concern. I think they are asking how to get a mechanical speedometer (spinning cable driven) to work on a car that has no speedo cable, instead it has a sensor in the trans or diff that works on an electric speedometer.

there are a couple ways, you could build a digital circuit that drives an electric motor at varying speeds and use the existing signal as input.

or more likely it would be easier to take apart your old speedo and install the guts behind an old speedo face. This would probably be the easiest.

I know of a lot of cable to digital convertors, but none to put a cable speedo in an electric speedo car.

i wonder if the cable to digital would hook up in reverse? use a gps and dont worry about the speedo workin lol. as for the gauges, they do require a 6 volt pressence to actually work(if they were 6 volt gauges) all you need is a resistor to go from 12 volts to 6 for power to the gauges itself

Originally posted by Russ-D

yeah the bulbs will just burn twice as bright. I dont think that is their concern. I think they are asking how to get a mechanical speedometer (spinning cable driven) to work on a car that has no speedo cable, instead it has a sensor in the trans or diff that works on an electric speedometer.

there are a couple ways, you could build a digital circuit that drives an electric motor at varying speeds and use the existing signal as input.

or more likely it would be easier to take apart your old speedo and install the guts behind an old speedo face. This would probably be the easiest.

I know of a lot of cable to digital convertors, but none to put a cable speedo in an electric speedo car.



Nope, the 6V to 12V wasn't my concern, just the speedo issue, but I figured I would field it before the thread became about that vs. how to get the cable driven speedometer to work with an electic speedometer sensor.

As far as I'm concerned, it not working is not an option, I don't like stuff half assed. If it's not going to function, you won't see it in my car in the end. But I know it can be made to work.

I might check in to swapping the guts, but I'm not sure if the face and such will allow that to work, not to mention, you then need the circuit board behind the dash, and that will just be another headache in itself. I plan to have the brake master cylinder behind there as well as brake plumbing and several other things to pull them out of the engine bay.

Do you have any referances for information on how to build a digital circuit to drive and electrical motor? I'm not an electrical person, I can wire up a radio or stereo, relocate some wires by lengthening them and set up door poppers, but that's about it.

bump..........I would like more info also

http://www.dicksspeedotach.com/

guess these guys do this?

Im in the same boat. I have a 55 dash I want to put into my toyota which is an electric speedo year. I had my girl call the local hot rod shops and they reffered her to a company back east. (Ill try to come back with the name.) Anyways they will take any mechanical speedo and completlty refurbishi it and convert it over to electric. They quoted me $3k to do the job but said mine was much more difficult because the speedo is a half moon sweep, standard sweeps are much cheaper. So there is a was if you have a little coin to spend.