Wiring Question

[woodjunky]

Well I installed a whole new Wire Harness in my 49', I purchased from RIW. It was not cheap but is truly a work of art, and very easy to install. I would highly recommend them. New gauges from our friend (Keven) which again was a awesome experience. He even had a Headlight Switch that I needed, as when removing the old harness one of the bullet connectors would not come lose, and the end result was it pulled the whole connector out.

New Tail Lights from Roberts.

 

I do have a question though with regards to the ignition switch. I know that the Brown wire fot the + Ammeter, Blue for Fuel, and Red for coil connect to the switch. But if you are looking at the switch from the key side or left to right where do these three connect ? Coil should not be hot all the time correct ? Switch does just have three posts.

 

Brad

[Merle Coggins]

Are there any markings on the key switch like "BAT", "IGN", and "ACC"? That would be "Battery" connection (from Ammeter), "Ignition" connection (to coil), and "Accessory" connection (for all other key dependant power.

 

Merle

[woodjunky]

No Merle there are not.

[pflaming]

So the back of the switch is a clock, on mine, with the key vertical, AMP (batt/power) is 12:00; COIL is 9:00; ACC is at 3:00. I have three switches but no keys, so I'm running off a toggle switch which I may keep, it's 'farm easy' to get in and go. If so, I will hide a disconnect.

[gramps1951]

can you tell me who riw is. wireing my truck is another thing i have been putting off. it dos'nt sound that easy to me. thanks neil   ps how much does a complet wire setup cost.

Edited April 22, 2013 by gramps1951

[Merle Coggins]

How 'bout that... I found that I had taken a picture of the back of the Ign switch. Not the clearest picture, but you can see the markings on mine. Just like Paul said.

 

RIW is Rhode Island Wiring. http://www.riwire.com/

[pflaming]

Unless you are a purist, I would rewire it myself, I did mine. If you do, get all the correct wire colors. I didn't get all the colors, BIG MISTAKE. 

[Barry Maxwell]

My ignition switch (which I think is original) has three terminals marked AM, Coil, and GA (the longest post). My understanding is the following regarding what's conected to what:

AM - ammeter and light switch (

Coil - Coil

GA - fuel guge, heater switch, wiper switch

When the key is turned to the right: AM connects to GA and Coil

when the key is turned to the left: AM connects to GA only

I also bought a Rhode Island Wiring harness. Many $$$ but outstanding quality. I am a long way from installing it.

Barry

[woodjunky]

Neil, RIW is a super nice company to deal with. Their employees seem to really care about what they do, and that passion shows in the craftmanship of the Harness. I had them include the 7-Wire turn signal switch, which also has the cloth covered, color cordinated wires. I had to solder on the bullet connectors for the turn signal wires, and front bucket turn signal wires. They include very easily read wiring diagraham with each Harness section.

 

It's really not that difficult. Really the hardest part is oil line that connects to the gauge. When you get that lose , and the old wires you can pull the whole gauge cluster out. Then start intsalling the new Harness here, and work into the engine compartment.

 

I paid just over $900 for a complete Harness which consists of:

 

Body Harness

Front Turn Signals Bucket Harness

Front Signal Crossover Wire

Rear Turn Signals Bucket Harness

Rear Signal Crossover Wire

Turn Signal Switch

15 .160 Bullet Connectors

12 .160 Female Connectors

 

Hope this helps.

[pflaming]

My oil line had a coupling inside the engine compartment. That disconnect the line inside is about a foot long and allows for a lot of movement of the cluster. 

[woodjunky]

Well looks like the general opinion is that Batt is at 12:00, Coil at 9:00, and Acc\Ga is at 3:00. Since my switch does appear that it has been replaced at some point, it does not have the markings.

I will try to make the adjustment tonight.

Thank you Paul, Merle, and Barry.

[Barry Maxwell]

 

My oil line had a coupling inside the engine compartment. That disconnect the line inside is about a foot long and allows for a lot of movement of the cluster.

 

As I recall, my oil line has a junction on the outside of the firewall as well, but it is still difficult to connect the oil line to the gage. A long flexible line would be the ideal solution.

Based upon a suggestion by Greybeard (aka Dave Erb), I had RI Wiring extend all the wires behind the dash by 6-8" to allow the cluster, ign. switch, etc. to be connected well in front of the dash. I recall that Dave said that it was so cramped behind the dash he enlisted his 8 year old grandson to do the work because he is "built like a snake". What ever happened to Dave? I learned a lot from all his posting several years.

[1952B3b23]

Well looks like the general opinion is that Batt is at 12:00, Coil at 9:00, and Acc\Ga is at 3:00. Since my switch does appear that it has been replaced at some point, it does not have the markings.

I will try to make the adjustment tonight.

Thank you Paul, Merle, and Barry.

 

I think if you have an ohmmeter and some extra time you maybe able to figure out which terminals on the switch are what. If the meter is reading "OL" then you know there is an infinite amount of resistance therefore that circuit is not complete between the two terminals you're testing. If the meter reads some value of resistance than you know the circuit between the two are complete. You could just keep trying different key postion/terminal combinations and see if you can verify the location of each one. Hopefully that helps, good luck.

 

-Chris

[woodjunky]

I believe I got this solved, however my Ammeter shows discharge with the Engine running. Also the fuel gauge not registering. I only put in two gallons of gas. I ran a wire from the positive battery post to top of sending unit, but still no change. When I initially turn the ignition switch on the fuel gauge does move slightly. This is a New sending unit also.

Any thoughts ?

[1952B3b23]

I'd try measuring the resistance at the sending unit and see what that reads. My understanding of how the fuel gauge works is it gets a resistance value (ohms) from the sending unit depending on how much gas is in the tank and then "translates" that to either full or empty or something in between depending how full the tank is. If the sending unit itself ouputs a resistance other than its value at empty then you know its working. I would also try to search for info on what resistance value it outputs at full and empty. That way when you measure the value it may actually be able to tell you something if you have data to compare it to. Good Luck.

 

-Chris

[Dave72dt]

Do you have power to the sending unit?  If yes, a simple test is to momentarily ground the sending unit wire.  You should get a reaction on the gauge.   If you get a reaction, the gauge is probably good.  No reaction, the problem is in the sender.

[B1B Keven]

Did you re-polarize the voltage regulator?

With no wires connected to the fuel gauge, it should read between 25 and 30 ohms.

[woodjunky]

Dave, I will try that tonight.

Keven I did not. How does one re-polarize the voltage regulator ?

[TodFitch]

Dave, I will try that tonight.

Keven I did not. How does one re-polarize the voltage regulator ?

Before "polarizing the regulator [sic]", do you have the battery installed correctly? The positive post should be connected to the ground cable which is the reverse of modern cars. . . That would cause your ammeter to read backwards too.

[woodjunky]

Tod, Thank you for the suggestion. Positive is connected to transmission mount.

[woodjunky]

Tried the suggestions lastnight. Touch groundwire to sending unit wire at the tank, gauged junped to full. Used test light on gauge, getting power.

My thought maybe since I re-painted tank, and the frame of the truck has been repainted it's not getting a ground ?

[TodFitch]

 . . since I re-painted tank, and the frame of the truck has been repainted it's not getting a ground ?

 

Definitely possible. Clean off some of that paint or run a ground wire.

[John-T-53]

  

...snip...  Based upon a suggestion by Greybeard (aka Dave Erb), I had RI Wiring extend all the wires behind the dash by 6-8" to allow the cluster, ign. switch, etc. to be connected well in front of the dash. I recall that Dave said that it was so cramped behind the dash he enlisted his 8 year old grandson to do the work because he is "built like a snake". What ever happened to Dave? I learned a lot from all his posting several years.

 

I haven't seen Dave around on the new site yet, wonder if he can find it? I agree, he always had a lot of good wisdom and wit to share with us.

[Merle Coggins]

I haven't seen Dave around on the new site yet, wonder if he can find it? I agree, he always had a lot of good wisdom and wit to share with us.

 

Dave is doing fine, the last time I communicated with him. He had some computer issues that was blocking him from posting to the forum so he kind of dropped out. I let him know about the new forum format hoping he'd come back around, but I guess he's found other interests to keep him occupied.

 

woodjunky,

 

Before you ruin a good paint job trying to get things grounded, run a ground wire to the sender body. I added a ground stud to mine just for thes reason. The threaded stud you see sticking up is actually a machine screw. I drilled a hole in an open area of the plate, next to the sender guts. Then I inserted a machine screw from the bottom with a little sealant under the head. Then tighten a nut down and you now have a grounding stud for the sender. From that I ran a wire over to a transmission cover bolt.

 

Edited April 25, 2013 by Merle Coggins

[JBNeal]

I ran out of gas in the '48 on the back roads while going up a long hill cuz I didn't calibrate the fuel float to read E when I had about 4 gallons left in the tank.  Since these tanks don't have baffles, 2 gallons of gas just barely submerges the fuel draw tube when the tank is level, and when going up an incline, that small amount of fuel sloshes away from the draw tube.  So I bent the float arm so that the gauge would read E when I had about 4 gallons remaining...that way when the gauge said E, I'd have enough fuel to head back to the gas station.  Also, I drilled a hole in the top of the sending unit, put a 10-24 machine screw with an external tooth lock washer & nut to act as a ground stud, then ran a ground wire to the battery to complete the ground circuit.  That settled down the jumpy gauge needle with better ground continuity rather than having ground interruptions at the sending unit lock ring, gas tank mounting bolts, frame rivets, motor mounts and transmission mounting bolts from corrosion.

 

Also, the '48 ammeter would show a small discharge while at idle, but when I'd get RPM up to around 1200, there'd be a clicking noise from the voltage regulator and the ammeter gauge would show charging