OK - probably a really really dumb question I'm still working on this thing but want to get it running enough to drive down to the drags - but have a question about the factory gauges that are in my '50 ford F2 - they're 6V gauges right? It's had a 289 swapped into it and the lights were converted to 12V so everything that's installed in it is 12V and it came that way - the dash was out of it and wondering if it's 6V or 12V.... Also - I heard a roumour that I can use the gauge movements off of a mid 70's pickup and put them behind my gauge "face" and they'll work great in the 12v configuration. Anyone know about this "trick"? If it all goes well I'll have the bearings replaced in the bottom end tonight, ****on 'er up and take it for a test drive - if it has more than the previous 3-5PSI oil pressure I'm driving it down with no backup. So if you see a broken down F2 sitting on the side of the road with 2 guys looking dumbfounded.....
All the Ford gauges are 6V well into the 70s. Go to NAPA and get an instrument regulator (Echlin IR-1, I think it is). Or get a newer cluster and take the regulator off of it. No need to change the gauge movements. Chris
You may have to adapt the original senders to the newer motor. Late model senders won't work with the early dash gauges.
With all due respect to blown49 (he was instrumental in helping me figure this stuff out ) you can use modern senders with early gauges. All the movements function the same from at least '40 through '79. You can swap needles and faces around as needed with a little patience. The thing with the senders is that they need to be the 73-10 Ohm variety. GM, S-W and other non-Ford senders operate over different ranges of resistance. With my '40 Ford gauges, I'm using a repro water temp sender from Mac's (the single post flathead sender), P/N TAN-ORG from Yogi's for fuel level and an oil pressure sender from NAPA for some 60's F150. Probably could have saved some money and got the temp sender from NAPA instead. The instrument regulator brings it all together to run on 12V. You can use your old senders, too, ***uming they worked on 6V. The only thing that doesn't read correctly is the volt meter, but you probably have an ammeter, so no worries there. Hope this helps. Chris
if you want to use the original guages you can use a runtz voltage reducer for fuel water and oil the ampmeter doesnt need one these will safely drop the voltage from 6 to 12 i did a search and someone listed patricks antique parts as a source
Check this thread over on Fordbarn: http://fordbarn.com/earlyv8/forum03/messages2/5125281.html There's some good debate on this thread re: fuel gauges: http://fordbarn.com/earlyv8/forum03/messages2/5124484.html The original Ford gauges used an unusual (by modern standards) setup. The senders can be replaced with modern ones carefully selected for the proper resistance range - good luck. Might be easier to use repro early Ford units & a true 6V constant voltage regulator (CVR) like the one sold by the HAMB's own Mart (see his HAMB-O-Dex entry or send him a PM). I've converted my '40 to 12V using Mart's CVR - quality product at a great price - even if he does wear funny hats from time to time!
Haha - good stuff in that second one, Ernie. Put me down for empirical truth. Just to complete the parts list for my setup, the oil pressure sender is Echlin OP6091 from Napa and the temperature sender was 8A-10884 from Mac's. I think the MPETS6178SB temperature sender from Napa would have worked just as well for $40 less than the Mac's part (which I believe is a reproduction using the King Seeley technology). There is also a OP6091SB for oil pressure that ought to work and is $13 cheaper than the one I used. They're both gauge senders and good to 100 psi - no idea why the price difference. Chris
Yeah, as mentioned, I used to think it wouldn't work based on how the originals work - until I discovered I'd been running one & it worked fine! This epiphany only happened within the last 6 weeks or so too! Had to re-think & then it became obvious...
Last 6 weeks? Really? It hit me about a year and a half ago thanks to something you posted when I was trying to figure out what to do with mine. When I was putting mine together in the winter of ought-six you suggested looking for mid 60's F700 gauges to swap into my '40 cluster. Unfortunately, there aren't a ton of mid 60's heavy trucks in my world. So I started looking around eBay. A lot of people are selling Ford instrument clusters from the 50s-70s and show pictures of the fronts and backs. Based on the similarities, I bought a 58 Ford pickup cluster for $7.00. Got the instrument cluster, light bulb sockets (they were the same most of those years, too), and confirmed the the gauge movement interchangeability. The only functional difference between the '40 cluster and the '58 cluster is the presence of the instrument regulator.
I made that suggestion based on info provided to me by another HAMBer & under the ***umption you'd use modern sending units. "Modern" movements & "modern" sending units seemed like the right combo for a 12V conversion. I honestly still thought the King Seely senders had to be used with the early Ford gauges until I pulled my tank 6 weeks ago & found I'd been using a replacement sending unit! At least I'm still learning things! I think some of the "instrument regulators" might be nothing more than resistors & some are real regulators - I haven't investigated this too much & when I converted my '40 to 12V last spring, I just used one of Mart's 6V CVRs - great piece, great price. My gauges have never been so accurate either! Until I pulled my tank & discovered my modern sending unit in my '40, I would have been arguing right beside JR Junky just as p***ionately! I knew it could be done with variable resistance, but didn't think the typical range for most senders would work, but hadn't investigated any further - I was smugly satisfied I knew what I needed to know. I was wrong!
I think you're right in the case of the 'Runtz' voltage drops - I believe they are resistors rather than regulators. The Ford part and NAPA replacement are regulators. You can see this if you hook up a multimeter to the output side. Multimeters are pretty slow as instrumentation goes, but fast enough to get a feel for the pulsed voltage signal that the instrument regulator delivers. You're also right in your last paragraph. Variable resistance works, but not with the more common aftermarket senders because of the resistance range. IIRC you're using a Radio Shack pot for your BATT gauge. Is that right or does the Mart deal take care of that too?
Thanks for all the info - I'm not going to wire up the ammeter as I'm swapping to a 100A alternator and don't want to run a 6ga cable all the way through the dash - I'd prefer to convert it to a voltmeter - guess I'll go looking around the junkyard for voltmeters off of an early ford and probably pick me up a voltage regulator. The origional engine wasn't in the truck when I got it so re-using the senders is out - I'll just be buying replacement units from the parts stores...
The '39 & '40 cars had a "battery meter" - it's more like a voltmeter...but it's not quite a voltmeter... All gauges are really ammeters, but I know what you're saying.
All the gauges could be considered voltmeters too.... given a resistance across the gauge the voltage across the gauge is varied by the variable resistance that is coming from the sender.... it's a simple series resistor circuit.... Well - I think I've got an idea... get a pot and put it between the gauge and ground, and then get a different gauge and run it where the ammeter went - adjust the pot to read just left of center when the engine isn't running (around 12.xv) and then to the right of center when the alternator is charging (around 13.x volts) - should get me the indicator that I want and not have to run a high-current feed through the firewall. Anyone see an issue with that setup?? If I can use the potentiometer to figure out the right resistance I can get a regular old resistor at the electronics store and eliminate the bulky pot under the dash...
F-1 amp gauges, just show what way the power is going. Wire simply runs thru a loop on back of gauge. Run it wrong way will show discharge, but will be charging...........OLDBEET
Right - but I'm thinking pull the AMP gauge and put in a oil pressure or fuel level gauge "movement" in it's place, but use the amp "face" as the background for a "voltmeter" Don't know how sensitive the gauge is or if they'll be enough movement with the varied voltage.
You guys make this sound REAL HARD !!! These old fords were 6v POSITIVE ground, you need to swich ALL gauges to there opposite poles. So they run NEGATIVE GROUND. I have a '55 F~100 that i did and didnt change any gauges that run electric. AMP gauge dont care whats going thru it, Fuel level gauge works, has a mechanical oil press gauge from a '55 F~350, water temp gauge is a stock. ALSO, Stated earlier in this post that all ford movement in gauges was the same from 1940~1979... Why would you even need to switch to the later gauge from a later truck ?? If the movement is the same... then there is no reason to switch, Right ?
I understand on the gauges - simple regulator and voltage swap and I'm done... Maybe I should start a new thread on converting an AMP meter to a VOLT meter and not run the high current charge wire through the vehicle.... ever wonder why the newer vehicles are all running voltmeters??
Because it's cheaper . I believe that Flat Ernie has the answer on getting the Batt gauge to work. I too would like to hear the explanation .... again
The '39-40 Batt gauge needs about 60ohms to function correctly on 12V. It does not need the polarity reversed. None of the early Ford gauges (except ammeters) need the polarity reversed. This is because they are not like modern gauges - all modern gauges ARE ammeters (true, you can figure out the voltage from an ammeter, but that doesn't change the fact it is an ammeter!). The early Ford gauges are different in that they use a bi-metallic strip that bends when it is heated. The heat is supplied by current running through some nichrome wire wrapped around the strip. According to the Service Bulletins, the original circuit has 60ohms of resistance - if you double the voltage to 12V & then double the resistance to 120ohms, you should get the same readings on the Batt gauge. It works. As way of explanation, a bi-metallic strip is nothing more than two strips of dissimilar metal bonded together. These two metals have different rates of expansion, so when heated, the strip bends. Current flow through the gauge generates heat & bends the strip. The strip is connected to a tiny gear train that moves the needle. This geartrain is even adjustable on the early Ford gauges for fine-tuning... For most early Ford gauges, run a 6V CVR to the power side of the gauges & swap the leads or run the wire the other way through the loop for the ammeter. If you have a battery meter, do not hook it up to the CVR, instead hook it up to the 12V source but add a 60ohm resistor to the circuit.
The Jalopy Journal
