12v Gauges
 

I'm converting my '47 Coupe to 12 volt. Has anyone else done this? If so, what gauges were used to fit in original dash. I've seen some with gauges replaced, but I couldn't find out any info. Any ideas?

Re: 12v Gauges
 

Can you use a 12 to 6 volt reducer? I believe all ford gauges were 6v all the way up until the 60's, even though the car was 12v. Typical ford, saved money by just using an inexpensive voltage reducer instead of producing 12v gauges.

Re: 12v Gauges
 

Take a look at http://www.how-to-build-hotrods.com/6v-to-12v.html

Re: 12v Gauges
 

I converted my '41 coupe to 12 volt negative ground. Used Runtz converters from Speedway for the instruments. No need to change the gauges themselves. Pretty easy to install, and have been working fine.

The horn is the trickiest. The horn relay must be changed, and that is not a big deal. But I have found no way to reduce voltage to the horn itself for which the horn still works. The horn actually works on +12 volts but sounds more intense. It might burn out if you laid on it too long.

If you stay with the flathead, the -6 volt starter will work on +12 volts, but might not last. There is an easy way to convert the existing starter to 12 volts by using the field coil part (the outside) of the starter from an FE series motor of the early 60's. The new starter donor should cost under $50.

Re: 12v Gauges
 

There are kits to reduce voltage to 6V with resistors to put on between incoming Voltage & gauges / heater blower motor etc... Also includes all the conversion 12V light bulbs in /on vehicle.

Re: 12v Gauges
 

Previous owner converted my '47. Summary: Coil/condensor changed; Rebuilt the starter; Substituted generator with 12v alternator; Put a Runtz volt reducer on each of the 3 dash gauges (no need to do amp gauge), Put ceramic volt reducer on heater motor; Changed all light bulbs to 12v. Kept horn relay and horns as-is based on fact they are rarely used. If you have directional signals change flasher to 12v. Have radio and elec clock (if any) modified by a professional.

Re: 12v Gauges
 

This is great info, my new-to-me 49 F1 has been converted to 12 volts but the wiring is a lost cause and I'll need to start over.

Re: 12v Gauges
 

You could just put normal 2 inch Diameter 12 volt ones where the original gauges are like in the photo or get the whole set from Dakota


http://www.dakotadigital.com/index.c...od/prd1003.htm

Re: 12v Gauges
 

My '52 F1 has been converted to 12V . The heater motor switch gets very hot after a few minutes . Would a "ceramic voltage reducer" take care of that ?
If so , where could I purchase one ? Thanks in advance = F F

Re: 12v Gauges
 

For the gauges use the reducer that is used for the gauges on a Mustang or other Fords into the 70's. It's a small unit that attaches to the dash and has two posts. One for the 12 volt source(ignition) and the other post to the gauges in series. Napa used to carry them or you should be able to get one from a vintage Mustang parts dealer. I recently used one from the back of a junk Mustang dash that I bought at a swap meet for $5.

Re: 12v Gauges
 

ford freak, the ceramic reducer is a ballast reducer used for ignition in chrysler products for many years. 50's thru 70's and more. cheap, any parts store will have one

Re: 12v Gauges
 

I think I would contact Classic Instruments if I were looking for a basic rectangular faced instrument that would be near the right size & shape with 12-volt works. They use them in their retrofit set ups. They claim that can do custom stuff too but I haven't talked to them. http://shop.classicinstruments.com/retrofits

Re: 12v Gauges
 

In reference to TJ's post, the NAPA # is IR1. That's what Ford used on '57 up thru at least the '80's. I also used this on my '48 F-1.

Re: 12v Gauges
 

Randy Rundle has the runtz wire wound dropping resistors for gauges on his fifth avenue internet garage site. I've heard some folks have had problems with the instrument voltage regulators but I don't know what all they were trying to power at the same time either. They may have been overloading them.

Re: 12v Gauges
 

They do custom stuff, but grab onto your wallet. I got a quote from them on a '40 dash insert(original style gauges but modern internals plus a speedo that looked like an original '40 but was electric) and I was quoted over $2000!

Re: 12v Gauges
 

There are a lot of parts on that insert but I don't know about 2 grand worth. The plain individual instruments outside the insert shouldn't be too expensive but you just never know now days. Replacement aircraft instruments are around 1 grand apiece after the aircraft manufacturer marks them up 1000% so I guess I shouldn't be surprised.

I've always known I was in the wrong business!

Re: 12v Gauges
 

I did a recent conversion to my 47 sedan.. I only used a voltage reducer for the fuel gauge.. all the rest I did aftermarket.

WALT

Re: 12v Gauges
 

TJ,
In '64 I built '40 Ford street rod and converted to 12V. I used the gauges and sending units from a ,56 Merc. They were the same as the '40 gauges. Looked stock. I know that would not be possible today but, check out some later Fords and see if the gauges will fit. Don't over look trucks. If you find gauges that fit then you just need the matching sending units.

Re: 12v Gauges
 

There are lots of voltage converters on ebay.

Re: 12v Gauges
 

Like these?
http://www.ebay.com/itm/Car-DC-DC-Co...3D252482388190

Re: 12v Gauges
 

The frequently used Runtz reducers, one each of three gauges, are $3 each at this site:

http://autorewire.ecrater.com/c/1168...ltage-reducers

Re: 12v Gauges
 

Interesting, must be 6 volt zener diodes.

Re: 12v Gauges
 

I've been around dropping and regulating systems for a long time and all of them generate heat. Most are insulated from making contact with flammables. The flea-pay stuff doesn't look like it has any way to get rid of the heat plus it has a two wire input and a two wire output. How are you supposed to insulate your load from ground?

I would be skeptical about the longevity of those products and whether they are safe to use or not. You certainly don't want your car to catch fire due to a poorly made product. -Caveat Emptor-

Re: 12v Gauges
 

rotorwrench,
I'm with you on the "flea-pay" stuff. I don't understand why everybody wants to complicate things. The NAPA #IR1 is what Ford did when they went to 12v. Works fine and lasts a long time and safe too. This is what I have on the two old Fords I have that are now 12v. Also, my '88 Ranger has this same unit to run the gauges!

Re: 12v Gauges
 

From Ron Francis Wiring: VR1 is a clean easy setup for 12V to 6V conversion. No resistors to heat up. Connect to 12V, clean consistent 6V out the other end will take
care of all you gauges.
Next to what oil to use, the most discussed on this board. OP should take
some time and search for previous posts on 12V conversions.
https://www.ronfrancis.com/prodinfo.asp?number=VR-1 $60.00


https://www.napaonline.com/en/p/ECHIR1

$72.00 from NAPA

Re: 12v Gauges
 

Certainly doing what you know works is a good bet. "switching" power supplies and "buck-boost" converters are much more efficient than a dropping resistor of some kind, and really don't generate hots of heat. They are used in all kinds of electronics.

Re: 12v Gauges
 

I used gauges from 70-80's ford trucks. they are exactly like , in appearance, to 40's stock movements. Also got matching senders. Used a Ron Francis VR-1 voltage reducer.
Newer gauge movements will fit exactly into the stock housings. Reassemble with the stock faces and no one will know the difference. May not match stock readings marked on the glass but once I got used to where they were reading, no problem.

Re: 12v Gauges
 

I found a used Mustang ('66) regulator for $20, so I'll go that route. At least it will look at home. 8^)

Re: 12v Gauges
 

I converted the gauges in my 47 ford coupe to 12 volt. Rodtechhrp.com provided a custom round hole plate that looks just like the original but with round holes for the gauges. I went with vdo Cockpit Royale gauges and they fit perfect and looks great.you will need to file the 90 degree corners of the dash hole just enough so they don't show through the gauge plate, but it was easy to do.

Sent from my SM-T800 using Tapatalk

Re: 12v Gauges
 

Dug these out of the rat's nest. Some heavy ceramic resistors measuring 3.5 ohms each. I assume they were to supply gauge voltage.

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The big resistors are usually for fan motors or accessories with higher amp loading. They have high in-rush current and can damage intricate instruments in some cases. The old King Seeley type systems are pretty heavy duty but no point taking a risk.

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Kind of hard to tell where there were attached...:eek:

Re: 12v Gauges
 

I'm using NOS 46 gauges with a 12 Volt system. I just use a reduce I got from Drake. Its one that takes care of all the gauges. Works fine.

Re: 12v Gauges
 

Even though I'm getting ahead of myself here a bit, I've been playing with gauges. I plan a new thread to share what I learn. My instrument panel is really messed up, while removing all the nasty wire, I noticed that there wasn't anything holding it in so I just removed the whole thing.

Re: 12v Gauges
 

You can, and probably should use the 6V horn relay. It doesn't care about polarity and the 6V units had heavier contacts. The horn will be much louder and 'angrier' (I like it that way), but short blasts are the order of the day. The 12V relays can and often do stick 'on' and you have to pull a wire off the horn or relay to get the horns to stop. Never had that problem with 6V relays.

That's the same kind of unit that Ford used up into the '80s. It's a chopper unit. It basically turns the full 12V on and off over and over again so that the gauges think they're only getting 6V. Works pretty good, but there are better solutions...that are cheaper.

I'm a fan of the fully electronic L7806 CVR. These little gems cost less than $0.10 each and can take anything up to about 19V and always output exactly 6V.

Only a CVR (constant voltage regulator) will produce a constant output of 6V. The choppers and dropping resistors will output some lower amount around 6V based on whatever input voltage it gets. So if your chopper puts out 6V when only the battery is connected at 12V, but your alternator is putting out 14V, the chopper will now put out 7V (or thereabouts). The only gauge that this matters on is the gas gauge. Even the stock systems will show one reading when going down the road at speed, but when you stop and idle and the generator cuts out and voltage drops slightly, the gauge drops too. With a CVR, this is eliminated.

You can get them at any decent electronics store, order online, and even eBay sellers have them. 1 will run the three gauges most of our old cars have, but they're so cheap, I always run one for each gauge. Simple 3-wire hookup - 12V in, ground, 6V out.

Re: 12v Gauges
 

While looking around for info about this, ran across this informational video on using the L7806 for powering gauges. Kind of long and slow but tells you exactly how to make them.https://www.youtube.com/watch?v=1gvQjwMrQ9k

Re: 12v Gauges
 

Wow...he really over-complicated that! :eek:

Re: 12v Gauges
 

TJ.......I live just down the road from Classic and went to their OpenHouse last year. Very nice stuff, but you're right.....very expensive ! They had a '40 Standard unit that included a tach in the lower area of speedometer for $750 at the time. Really kool, but too much $$

Mike

Re: 12v Gauges
 

Estout........how did you hook these up ?

Re: 12v Gauges
 

What you really want for as little heat as possible is a series regulator as in 7806-8.
It just turns out enough for what you need instead of burning of the excessive like in a resistor or dropping diode (what you call runtz).
Next issue with a diode is that you got 2 failuremodes...open gages just stop working...shorting out gages have a chance of burning up...so make sure it´s big enough to cope with the dissipation.
Surrounding temperature is a big factor in how good any solid state dissipating heat works so dont stuff it in to tight.