Topic: 1937 dash wiring


Junglejim    -- 06-24-2020 @ 8:06 AM
  So, long story short. I bought a 1937 ford when I was 16 back in 1997, since then I have fiddled with it when I could but never with intent. I recently shipped it from my child hood home to my current residence and am finally trying to figure things out. I have a few issues. First its pretty much original, minus an electrical fuel pump and 1940's dristributor. So the head lights are super dim and my brake lights hardly work at all. When I have the head lights on and depress the brakes they dim so much I cant see them and the brake lights dim as well. Under the dash I am trying to understand the "rats nest" of wires. What I would like to know is how does number 1. measure amps? How does #2 measure oil pressure, and what is the purpose of this coil? Does the generator appear OK?
Thanks
Jimmy


Junglejim    -- 06-24-2020 @ 8:17 AM
  Forgot the pictures


MG    -- 06-24-2020 @ 10:10 AM
  As you can see, the amp gauge has a loop around the wire. Induction from the wire is induced into the loop which moves the needle of the gauge.

What you refer to as a "coil" is a resistor wired in series with the ignition coil.

Oil pressure gauge is wired to a sender/sensor which is scr*w*d into the back of the engine block on the drivers side....

What "generator"???

This message was edited by MG on 6-24-20 @ 10:17 AM


Junglejim    -- 06-24-2020 @ 11:01 AM
  Generator


Junglejim    -- 06-24-2020 @ 11:03 AM
  So if the amp gauge does not move at all, do I have an issue? What is the purpose of the resistor?
Thank you
Jim


MG    -- 06-24-2020 @ 11:14 AM
  The amp gauge should move pos. or neg. to show charge + or discharge -. If it does not move at all, yes, you have an "issue". Have you checked the fuse (as seen in the picture you posted) for continuity?

To operate correctly, the ignition coil requires less than 6 volts and therefore the resistor is added to step down the voltage presented to the coil....

The picture of the generator you posted looks to be correct for your car....

This message was edited by MG on 6-24-20 @ 11:43 AM


Junglejim    -- 06-24-2020 @ 12:36 PM
  Thanks MG,
The fuse is intack, still no variability as i run the car, no matter the RPM.
Does any one have a picture of the wiring under their dash of a 1937 car?
Jim


51woodie    -- 06-24-2020 @ 1:25 PM
  Jimmy. Welcome to the EFV8 Club. It looks like you made a good buy when you were younger, congratulations. Hopefully, you are going to keep it stock and enjoy the pleasures of owning an old Ford. The big issues with these old Fords is bad grounds and the plug in connectors. There are all sorts of posts on this site, that addresses these issues, if you do a search.

When I bought my '46 Coupe, if found the lights were dim as well, and it didn't crank over very quick, but I learned from this site. Assuming you are still 6 volt, positive ground, make sure you have the correct gauge of battery cables, from + to ground and - to the solenoid, and from there to the starter. I can't recall the gauge size, but someone will likely post it here. Our 6 volt systems draw more current that 12 volts, and previous owners sometimes replace the cables rated for 12 volt systems that draw less current. The other thing is, the cables need to have proper ends, that are soldered or crimped. All the cable connections need to be taken appart, cleaned of any paint or corrosion and re connected. In the wiring harness, the plug in connectors need to be taken appart, cleaned with small wire brushes and checked for a tight connection when plugged back in. Check the ground connections at the head and tail lights as well. Hope this helps.


40 Coupe    -- 06-24-2020 @ 1:49 PM
  The resistor you show in one photo seems to have a broken mounting board. It should not hang in the air by the wires. It is to reduce the voltage going to the ignition coil. If your vehicle is still 6V the coil runs on about 3V.


MG    -- 06-24-2020 @ 2:31 PM
  The amp gauge may have a stuck meter movement due to the car sitting idle for an extended period of time. Turn on the headlights and then tap on the back side of the gauge ( or even the front side) and see if by doing this the gauge frees up....


3w2    -- 06-24-2020 @ 3:49 PM
  Your owners manual will have a wiring diagram in it, if you have one. If not, they show up with some frequency on ebay, Amazon, and on this site.Another worthwhile investment is the Club's '37-'38 book available on the online store in this website. It is loaded with lots of accurate information about '37s (and '38s) based primarily on Ford's archives. Two other worthwhile investments would be the '37 edition of the chassis parts and body parts catalogs. While not reprinted, originals show up frequently as with the owners manual.


TomO    -- 06-25-2020 @ 8:52 AM
  Here is a link to the wiring arrangement on a 1937 Ford

http://vanpeltsales.com/FH_web/FH_images/FH_electrical-pics/Flathead_Electrical_wirediagram1937car.jpg

Here is a link to the wiring schematic for the 1937 Ford

http://vanpeltsales.com/FH_web/FH_images/FH_electrical-pics/Flathead_Electrical_wiring1937.jpg

Your lights need at least 5.8 volts to be bright enough to see. They should have 7.2-7.4 volts when the engine is doing 20 mph.

You will need to know how to use and understand a volt meter to find the problem.

If you don't have one or are not sure what it is telling you, you can try the following:
Make a jumper wire from 12 gauge wire and long enough to reach from the battery to the head light bucket wiring. You will also need a thin probe to get into the connectors.

Run the jumper from the battery to the connectors on the drivers side of the car and insert the probe in each connection and observe the lights with each insertion. If the lights are normal brightness, the sockets and wiring is good, if they are dim, the bullet connectors have corroded and need to be cleaned.

If you want the voltmeter procedure, I will post it.

Tom


ford38v8    -- 06-25-2020 @ 11:41 AM
  Jimmy, What the others have said here is good, but I have a couple more things to add: The picture of your generator shows an original cutout switch. Modern solid state replacements include a voltage regulator in the unit, and are quite reliable. These are available at:

http://www.funprojects.com/products/10505v.aspx

Also from that picture and from your comments, your generator may be in need of adjustment, as it appears to have been untouched for quite some time. Being a three brush generator, the third brush is adjusted up or down to provide the proper charge rate.

Lastly, also from that picture, in the lower right corner there appears to be a cylindrical coil mounted. If this coil is internally resisted, you will need to bypass the under dash resistor. An analog voltmeter is an invaluable tool for use in all these questions.

Alan


Junglejim    -- 06-25-2020 @ 8:59 PM
  Thank you for the feed back
Tom, please post how to test my generator, I have a voltmeter, I used it to check my ignition coil. I am trying to understand my wiring, so I can get it the best it can be.
Alan, I do have a new ignition coil, how do I test if I need to use that resistor? How do I adjust the third brush? And check the output?
Do you guys use LED lights in your car?

1937 Ford model 78 fordor


ford38v8    -- 06-25-2020 @ 10:10 PM
  Jimmy, I think TomO is able to give you better instructions on those procedures than I would be able to. You'll find that he is one of our most valuable resources on technical questions.

Regarding LEDs, I think TomO runs them in his tail lights, so again, Tom's your man!

Alan


TomO    -- 06-26-2020 @ 8:05 AM
  Jim,

Alan gave you great advice about the solid state voltage regulator from Fun Projects. If you install one of those, you will not need to adjust the 3rd brush.

To check the output of the generator, connect you volt meter between the B or BAT terminal on the cutout and ground. With the engine stopped it will read battery voltage. Start the engine and increase the rpm to above 1,000 rpm. The volt meter should now read above 7 volts. If it does not, the cutout could be bad. If the generator doesn't give you more than battery voltage, jumper around the cutout long enough to read the voltage. If you get the 7 volts the generator is good and the cutout is bad. If you get more than battery voltage but not 7 volts, the generator may need repair.

I have led's in my tail lights and they work great, they are at least 2 times brighter than the bulbs. I check my lighting system every year to make sure that I get good voltage readings at the light sockets. I get 6.0 volts at all of my sockets with the engine off.

The Ford coil that uses an external resister has 0.6 ohms primary resistance, the one that doesn't need an external resister has 1.2 ohms primary resistance. You do need a coil that is rated for POS ground and the - terminal goes to the ignition switch and the + terminal goes to the distributor.

Tom


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