Years ago I read an interesting article that said Ford (may have said other makes as well) didn't switch to 12 volt gauges until sometime in the 80s I believe. They said Ford switched to 12 volt in the cars but continued 6 volt in the gauges and that on the back of the gauges would be a little reducer. It went on to say that all you needed to do was go to a wrecking yard and find a car that matches the number of gauges you had, with a 1956-early 80s Ford car with the same number of gauges. Then just pull the one out of the junker or go to a parts store and order a new one for the exact same car. Wire it into your gauges and voila, you now have 6v gauges running on 12 volts. Has anyone else heard of this or done this? I did this on my 52 Merc and it seemed to work but maybe I just got lucky. I have never heard anyone else talk of this. If it's true it's super easy and inexpensive.
Yup, it's a very common fix. The gauges in my '50 Ford are done that way, as well as a number of others I've done. Trouble free way of running 6 volt gauges in a 12 volt system.
Here you go.... You'll find one of these on the back of all 12v Ford instrument clusters somewhere up until at least the late '70s, the mounting bracket location may vary. This is a '64 dash. One reducer services all gauges.
I used my last one from a mid ‘70 Dodge van. Some of the later model Ford reducers were a bit different as I recall, I think they plugged in with round studs not spade connectors, or maybe I’m confusing it with the later Dodge ones?
Just seen way to many people fiddling with homemade or store bought reducers that are either ugly or bulky or both. This is the best way to remedy an age old dilemma.
Plus side of using a factory reducer is you just need one for all the gauges. You swap the bulbs out for 12 ones. The aftermarket ones are “per device”.
In 1956 Ford went to 12volt gauges. It was a disaster, so in '57 they went back to the tried and true King Seely 6V units. They used this basic design through the mid 80s. The King Seely Gauges are very accurate. It's best to use genuine, known good senders or NOS units. They can be repaired. (Tubman-Ford Barn)....There has been some bad reports about the repro-senders. When you get into the 60s, use senders designed for sweep gauges. Some senders are for the gauge lights (idiot light) and will not properly run a sweep gauge. They are more or less a simple switch. The reducer is actually more of an interrupter. It actually does not reduce the voltage, it interrupts it. Inside of them is a little switch that trips thousands of times....thus the gauges read this reduced flow as 6V more or less.
Since I didn't have any wiring in my car when I got it I'm having a hard time trying to visualize how this all goes together. Sent from my moto z4 using The H.A.M.B. mobile app
With the exception of voltmeters/ammeters/tachs, almost all electric gauges use a variable ground resistance sending unit to operate. The voltage reducer takes 12v input and 'drops' it to 6v. It doesn't actually reduce the voltage, it simply makes/breaks the circuit rapidly so that the gauge sees an 'average' of 6v. This is a common trick, the '120v' at your wall outlets actually has a peak voltage of about 180 volts, but the RMS (root mean square, and not the same as 'average') voltage is 120. If you look closely at the above pic, the connection with no wire on it is marked 'ign' and is input power and the other terminal is output to the gauges.
Step number 13 here: https://darksidersrealm.forumotion....lt-positive-ground-to-12-volt-negative-ground The original article for this dealt with a 1955 Ford years ago the regulator commonly used was early Mustang units this diagram shows how it is wired in.
Be careful with this trick, though...it works with Ford and Mopar gauges, but not GM gauges. Something about the gauges being either thermal, or magnetic. Thermal gauges have a slow response time, so the "average" voltage regulation works ok with them. But magnetic gauges move fast, so you have to feed them a relatively constant voltage. side note: Hudson used 5 v gauges in the early 50s, and they have a voltage regulator like the Fords...and if you feed it 12v instead of 6v, it still works just fine.
If you need to reduce voltage, you could use an electronic reducer, such as an LM7806. consider the maximum rated current it can handle, though.
There is a real good thread on here from 2010 I think where you use the 7806 and two capacitors and a heat sink. People debate the need for capacitors, but they are cheap and easy so I made mine just like the post. The heat sink is probably debatable depending on where you glue them. If you can glue them. Again, the heat sinks are pennies for how small of a piece that you use, so why not. My gauges worked great. I believe the subject line was "how to build a voltage regulator for $3". The ones I made are likely one of the last follow ups to that post.
What supplier has these now. They appear more robust than a tiny electronic gizmo . We have three 1936 ford gauges we need to run on 6v. We don’t have yards full of 60s and 70s fords here to pick over. Thanks.
12 volt to 6 volt reducer for gauges - Search Amazon.com : 12 volt to 6 volt reducer for gauges They aren't cheap but Merit Automation a seller on Ebay specializes in voltage drop reducers of different ampherages Items for sale by 72tx340 | eBay Now I am going to have to post a new thread with a question that will stir up the spit and whittle club.
Here’s a Google search for 1974 Ford Gauge regulator https://www.google.com/search?q=197...ator&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari Our local auto parts stores carry them as well, but I haven’t looked locally in a few years. Just to show you still source them
There are different types of gauges, and some work with the Ford regulator, some work with the electronic regulator. The difference is whether the gauge is thermal, or magnetic. Fords and Mopars (and Hudsons and a few others) used thermal gauges, and need the thermal regulator like that. GM used magnetic gauges, and needs a constant voltage source like you'll get from the electronic regulator. tell us what you're working on?
Why wouldn't a thermal gauge work with an electronic regulator? A constant voltage would be like running it on a 6 volt battery, wouldn't it?
It might, give it a try. But a magnetic gauge will not work with a thermal regulator. Which is what budget36 was suggesting.
The 78 series of regulators are good, reliable, overcurrent and overheating protected (and have been around at least since the 70s), but you need to know a few things to use them successfully. For starters, they have a minimum voltage drop (called dropout voltage) around 2V, meaning the input voltage HAS to be at least 2V above what you get out. A 7812 12V regulator needs minimum 14V in to give 12v out. Works when the engine is running and you have >14V from the alternator, but not with the engine off and the battery closer to 12V. The voltage drop across the regulator in combination with the current through it heats the regulator. A little heat is fine as is, more heat requires it to be mounted to a cooling fin (and the regulator back is grounded so the cooling fin will be too, without insulation between them). If memory serves me these can handle at most something like 7W with a big cooling fin. The power heating them is (input voltage - output voltage) * current = watts (14V in - 6V out) * 1.5A = 12W Meaning you can't get anywhere near the maximum 1.5A output when regulating 14V to 6V even with loads of cooling. On the other hand, running just 0.1A it would be 0.8W to handle, and that's far easier. I don't know how much current gauges usually need, but it's a thing you want to keep an eye at before choosing a solution.
This is what I used on my '50 Olds. Think it was called a volt-a-drop or something. Ran 12v. to the starter, everything else off this thing.
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