I’ve got a restored ‘34 Plymouth gauge cluster that I’m attempting to use in my ‘35 5 window custom project. When the time to hook up the sending unit came, I gave the company that rehabbed the instrument cluster a ring to figure out the sending unit resistance parameters. The guy didn’t know, but promised me he’d look into it and give me a ring. A day later I got a call and was informed that, after extensive research, he was pretty sure that the gauge would require 0 ohms for a full reading and 125 ohms empty. This sounded pretty odd to me, so I figured I’d check it myself. Sure enough, running 12 volts through it with no resistance pegs the needle, running it through 120 ohms on the sender (ground) side shows just above empty, and 130 ohms shows just below empty (I didn’t have any 5 ohm resistors to check the exact recommended 125 ohms). Now I’ve got to come up with a five hole sending unit that meets those resistance needs, and boy am I striking out. Oh, and the tank is 11” deep. Hmmph. I’m hoping there’s an electrical guru somewhere around here that will say “Oh, you need a sending unit from a 1986 XYZ.” Any ideas?!? And here’s an artsy fartsy pic of my current state of assembly (or disassembly):
can't help you with your question but I do dig the artsy fartsy pic I like the plywood paneling, it looks like your shop is in the den
Are you sure that the guage is setup for 12 volts, it could be setup for 6 volts, or it could have it's own voltage regulator. Try here. http://www.stewartwarner.com/Tech/faqSc.html
@Kenneth Thanks. Yeah, that's the first thing I thought of. The instrument restoration service said that everything had been converted to twelve volt, but I questioned that immediately. So, I ran it through a twelve to six volt reducer and at zero ohms, it would only hit 7/8 full. Obviously, I can't go any lower than zero resistance, so they must be right about the voltage and the ohm range. I dunno......Thanks for the help, though.
This is a picture of an NOS factory 35/36 Plymouth tank unit, and it has five holes. I've got one and I will try and check the resistance range and measure the dia. tomorrow.
Turkey, I want to make a point. Although I couldn't help on this question, I do try to answer questions when I can here and on other forums. My biggest pet peeve is people asking questions, then NEVER taking the time to write a simple "thank you" or any type of appreciation. Make me not care when I see questions asked, thinking "why should I go to the effort of typing out a long response, when they can't even say thank you". I just want to thank you for restoring some faith in me wanting to help with tech again.
You can get a brand new one made for your car. The company that made your original sender is still in business, and still makes your sender: Atwater Kent. Go here: http://atwaterkentmfg.com/Fuel%20Senders.htm#21 Also, on my '38 Mopar I used a generic replacement from JC Whitney that isn't exactly the right resistance, but gets the job done and is adjustable for different tank depths and was cheap. When I got it the JCW part number was 12ZX8525U. I don't see that number on their site now though so you may have to call them.
I checked the resistance on my sending unit. It measures .5Ω in the full position, and 133.3Ω in the empty position. The arm and float drop a total of 7¾". The unit measures 2¾" outside diameter, and the circle for the 5 screw holes measures 2 3/16". The P.N. 614463 is an early number for a tank unit (except '34), and listed as a universal unit. The unit with the red MOPAR package is P.N. 648438. It is for a '36 Plymouth and is still available @ http://www.mmpar.com/mmpars/default.aspx I don't know the price. I paid $80.00 for the 614463 at the Springfield, OH swap meet last week. The vendor had a duplicate, and I'm sure he'll be there for the mid-November meet. There have been two on ebay the last year and they have gone for $160.00 to $180.00 as I remember. I hope this has been some help. The old MOPAR stuff was all 6V, but that shouldn't make any difference as the resistance is in the correct range for your gauge, and the float arm could be easily modified for you tank depth.
@ 4Woody and Flatoutflyin, Thanks to your info, I think I've got the mystery solved. BIG help!! @ Prewarcars4me Thank YOU for blowing sunshine up my a**! That always feels good!
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