12V with stock fuel sender and gauge?

Unknown

I have a 12V conversion on my 1949 coupe, and have been running for a long time without a gas gauge. Just curious if the stock gauge and sender will work with 12 volts.



I use the knee against the bumper gaurd, shake and listen method to see how much gasoline I have.



Thanks.

Unknown

An even better way to keep track of how much is in the gas tank is to write down the odometer reading. Figure 16 mpg - so in 160 miles you'll use 10 gallons. At 250 miles, start looking for a gas station!!!!!!!



Have a good one.



Hudsonly,

Alex Burr

HudsonTech

Unknown

It's been awhile since I did this but I seem to remember it this way. The sender will not be a problem since it is a variable resistor. My '54 Hudson used a resistor mounted to the back of the instrument panel (or right in that area) that handles voltage overload to the gauges. It is looks like a small metal box with two terminals. Bottom line is I didn't need to do anything special as far as the gauges go, after all the worrying I did over how to handle the problem it just worked itself out. If you really want to be sure I suppose you could run two of the stock resistors in series in between the hot wire and and the gauges. Mike.

Club Coupe

The resistor metal box did not appear until the 1951 models. It may have been 1950 that had the box but I am positive about the '51s having it. You will most likely need to use reducers. There are some available from JC Whitney (part #WA710376Y at $17.99). All that being said, see how your gas gauge works before adding the reducers. I have heard both opinions as to using reducers or not and as "lookout" said, the problem may not be a problem. One last thing, Ford Truck Gas Tank Sending Unit #01A-9275 will work on a Hudson. Some Ford Dealers still stock them. If not Classic Ford, Dennis Carpenter, etc. have them. They run around $35.00. Also available through Stewart-Warner.

Unknown

Thanks a lot guys.

Park_W

There's a NAPA voltage reducer that works better, no more expensive, and saves you mail ordering from Whitney. It's listed as a replacement for '60s Fords. NAPA/Echlin Part IR-2. Use it to power the two gauges, as was done beginning in '51.

Unknown

Park, I recently had my gauges reworked by D&M Restoration; he recommended a NAPA resistor, # IR-9. Do you know the difference or is it significant enough to worry about?? I purchased both but the car still isn't back together (it's running now and will pull itself in & out of the garage & up/down the driveway, etc., at this time). All comments appreciated.



John

Park_W

John, I'm not familiar with that IR-9 unit, but will check it out at NAPA. The '50 and earlier gauges were actually made to be somewhat insensitive to the voltage supply, but putting 12v on them is almost certain to shorten their life, even if they indicate properly. These critters have bi-metallic strips with contact points on them, in both the sending unit and dash unit (as do the IR-2 and the original '51-'54 Hudson regulator unit). These contacts in the earlier gauges open and close fairly rapidly during normal operation, and they will do so a lot more with higher voltage applied. I must confess I've not experimented with the IR-2 on the pre-1951 gauges, but for the later ones, 12v through the IR-2 produced the exact same readings as 6v through the original regulator. Because of the design of the earlier gauges, I don't believe one actually needs a "regulator" ... a simple resistor should work. I have access to some NOS gauges and a couple of good sending units ... give me a few days to run some tests and see what resistor value works well.

Unknown

yOUR FUEL SENDER WORKS ON A GROUND PRINCIPAL AND IS NOT AFFECTED BY VOLTAGE. THE SENDER WORKS THE SAME ON 6 OR 12 VOLT. NOTHING ELSE NEEDED. HAVE CHANGED DOZENS OF CARS TO 12 VOLT WITHOUT ANY MODIFICATION TO FUEL OR TEMP SENDERS, GOOD LUCK BILL ALBRIGHT

dave s

I agree with Bill. I have been running 12 volts on my 51 Hornet for 15 years with original sending unit and dash gauge. I have put over 30,000 miles on it with no problems.

Unknown

Thats exactly what I was thinking guys.

Dad, and Grandpa say to use a vlotage reducer.

I'll give both ways a shot and see the results.

Park_W

Those who wish to run 6v equipment on 12v are certainly welcome to do so, and certainly some things will work that way, a tribute to the safety factor that Hudson and Auto-Lite built into these components (though in the case of the gauges, my bench test results showed they read somewhat higher than actual when operated on 12v). However, conservative engineer that I am, I prefer to make the appropriate modifications so the various items and systems operate at their designed stress load. Maybe the difference in longevity of the equipment turns out to be inconsequential in some cases, but I prefer this approach and stand by my comments above.