hi, I need a wiring diagram complete for a 49 Ford f1 ,it's been changed to 12v and has an alt. one wire.,the wiring now is all messed up. I don't claim to be a wiz w/ wires but if I could get a diagram to follow, I'm sure it'll be fine. I was just going thru the electical links and I read an answer from Docvette, he told the guy to post the info and he could help him out, so could you please help me? thanks for any help,JoJo

Doc here,

I Don't have any Ford diagrams for that Vintage, But I'll help you If I can..

First tell me what system you have? A kit newly Installed? or 57 year old cotton clad wiring adapted to 12 volts? Or a a split buss, 1/2 6 volt , 1/2 12 volt Via Dropping resistor? What changes have been done..?

Next, Tell me your problem with as much relative detail you can think of..

Maybe we can figure it out..

Doc

__________________
Aftermarket Solutions
Electronic & Electrical
Innovations

doc, my 49 was rewired by the prev. owner, all the same color, taped together in a harness type, it has a one wire alt. 12v. bat.,it looks like a resistor w/ power I think coming from coil in w/ two wires coming out to an elec. fuel pump, and 1 wire to the dist. It's all confusing I want to change everything to 12v coil,solenoid, the wiring is in great shape, not a harness, but new wire just the same. I bought a new i2v guage set up for the dash, gas gauge,sending unit. I want to do away w/ all the 6v stuff and I was hoping you could shed some light on how to go at this correctly, cause the truck is in real nice shape and it runs strong for a stock 239. any help will be greatfully appreciated thanks JoJo

Doc here,

I can't really tell you what you have, as it has been modified by others..That resistor could be a dropping resistor for 6 volt stuff Or it could be a Ballast resistor for the coil.. It's hard to tell..I suggest you remove the 12 volts from it, and see what quits functioning..that will give you some incite on what it does.

Changing the gauges is simple, just physically mount them where you want them, Traditionally the back of the gauge will have 3 terminals marked "S" , "G" , and "I".

The "I" terminals of all gauges will wire to a single fuse point (about an amp) and into a switched 12 volt source.

The "G" side will do the same EXCEPT , no fuse is required , and the tie point goes to a properly bonded (burnished paint, star and lock washers) central ground point.

The "S" terminals are the sender wires..these are run to the sender..a Sender is NOT voltage dependent..it operates on resistance referenced to ground..

You need to ORDER the proper sender resistance value for your gauges when you buy them for your engine application..and Fuel tank app.

The ones you have now may be fine, or may not work , you need to measure the resistance value for those (throughout the range) to be sure, or just order the right ones...

Are you planning a Voltmeter?

I advocate using them, Amp gauges are plain hazzardous..they can short or can BE shorted with tools, under the dash and place the full wrath of the battery to ground under the dash, melting metal and starting fires..With a Volt gauge all you need is a fused (like an amp), switched 12 volt source and ground, and they operate every bit as good as an amp meter..

I know you say the wire is new, and very good, but now is the time to make some hard decisions..since your going a full 12 volt upgrade (which is a good thing)..

Some things to think about AND plan for.., Is the heater motor, and speed control ,12 volts or 6 running on a resistor?

What about wipers? electric or Vacuum? do you need to upgrade?

What is the operating voltage of the Coil?

How about the Horn and Horn relay?

Are ALL the lamps 12 volts? or some 6 some 12 (including instrument dimmers)

As you plan for that, consider this..your wires are new and look good..may work good too..BUT.. do you know what they do? Where they go to , and come from? If not consider a harness kit, and do it all at the same time..If not..in the future..when you need to trouble shoot, or add circuits..you have a bundle of 25 "nice new Blue wires" ..But where do they go? ..what wire is the one I need? I advocate a Kit in this case..

At the very least go to the hardware store get a "Wire numbers " kit, and some clear plastic tubing..and a Pack of 500 small tie wraps..Disconnect ALL of your harness, and take a few days to a week or so to ohm it out and place a number marker at each end of the wire, then cut your tubing in about 3 inch lengths and place over the number you wrapped around the wire, then TIGHTLY cinch each end Closed with a tie wrap..do that until EVERY wire is identified AND make a drawing of your progress as you do..this will serve as your wiring schematic in the future. Scan a copy to your hard drive and save one with the Truck..Do it like this Example:

Wire Function.......Wire Number...............Device

Power Coil:...............34.....................Ign Coil+
Tach.......................58..................... Ign Coil-
Park lamp L...............24.....................Left front park lamp
Brake Switch +...........9.....................Brake lamp switch

And so on...

At least when done, you'd have some idea of what the wires do..however cost wise it's cheaper than a kit, but time wise is twice as long as installing a kit..and you may need to do some repairs/additions to the harness now..

just some things to consider..

Doc

__________________
Aftermarket Solutions
Electronic & Electrical
Innovations

Doc, I can't really say for sure about this wire mess I have . I just got a wiring diagram from Classic Car Wiring for a 49 f1, and I was wondering ,cause its for a 6v pos. grnd., if I followed it except to make everything neg. grnd. if that would work? also would I have to change the ign., & light switch? the heater is allready changed to 12v.motor,and I changed the coil, solenoid to 12v if that would work ok? also on the Classic diagram it shows a circuit breaker but there's not one in the wire harness this guy did. Do I have to have one on the 12v system? also there isn't a fuse anywhere. I know this is a lot of questions, but I'm a little short on cash and I'd like to do this w/ as little cash as possible, cause there aren't that many wires on this truck. so if you can help I'd appreciate it, thanks again, JoJo

Doc here,

It sounds like your harness is really piece meal.

The First RED FLAG, is that there is no FUSES or Fuse links..Your just courting disaster..No Fuses or links just provide the only "Out" a dead short has ... Burn up the harness to stop the short..

You can have Total, (not recoverable, burn your rod to the ground,) Fires and at the very least destroy whatever good harness you have. The Fact that someone would wire a system and NOT properly fuse it, Confirms the fact whoever did it, didn't have a clue..and most likely there is much more wrong where you can't see it..

To Convert your Total system From Scratch:

You will need to change:

• Starter
• Solenoid
• Coil
• Heater motor AND speed control
• Wiper motor
• All lamps , including dash, and domes, Backups, hood and glove-box.
• Turnsignal flasher and hazard flasher
• Horn
• Horn relay
• Charging System
• Any and all relays
• The need for a 6 volt (low Current) regulator on the Gauge power, or update to 12 volt gauges.
• Radio upgrade, or 6 Volt (high current) regulator.
• Wiper Motor upgrade, (if not Vacuum) as well as washer motor (if it has one, AND it's 6 volts)..
• Possibly the dimmer rheostat, (it may no longer be as linear on 12 volts as it was on 6..you'd have to test that..)

The wiring sounds like it is intermingled old "Cotton Clad" with new..another disaster in the making..Rodents LOVE that stuff to feed (It is a grain) on, and build nesting material..leaving you with bare wire..And..After 57 years of soaking up petroleum products, that Clad wire is more of an Explosive or firecracker Type "Fuse" than a wire..It will support a flame quite nicely, that will travel along it as long as it has fuel and oxygen to feed it..


An Electrical fire is unlike any other..most guy's blow it off.."It's only 12 volts..how much damage can that do?"...Overlooking the fact that it is 12 volts at 1000 Cold Cranking amps..

Your HOUSE only requires 125 AMPS to run it..SO that battery is providing current equal to your house and 7 of your neghbors..Your Welder probably only needs 50 to 100 AMPS..

Would YOU wire past ALL the fuses in your home and Sleep well at night? Why not? IT'S only 125 AMPS....

(this is reverse logic for Vehicle wiring..12 volts at 1/2 an amp to ground will probably heat the wire and burn your fingers..1 VOLT at 50 amps to ground, will start a fire, and cut metal..)

Once you have a " DEAD SHORT " on an unprotected system, the energy is used up in HEAT..

That heat will Ignite flammables (that normally wouldn't Burn at lower temps) around it..and burst into flames..The wire insulation or bundle is most common..melting YET more wires together..making more shorts and more heat and more fire..

"No SWEAT..Got my handy~Dandy Fire Extinguisher Right here..that'll put that mother out.." ... I think not....You may knock down the Flames..

BUT it will Continue to Burn, until the fuel source is removed..THE battery..

Now, because of fire and heat you probably CAN NOT get to the battery cable to try and cut it, (and I wouldn't advise it anyway..) So the only other option is wait until the battery EXPLODES removing the Fuel source..

For those of you that have seen a "Good" Battery explosion..know it can blow off fenders, hoods , grilles, and the Poisonous Shrapnel Can KILL anybody in it's trajectory, not to mention the Chemical burns sure to follow.


Quote:"But My Homey , Said I Didn't need Fuse links.."
If you NOTE the Crime scene tape..The FD is waiting for the Battery to go..after 15 minutes of overhead water..to no avail..

I find it really strange for guy's to say: I just spent, $4000 for Baher Brakes..to be safe ... So I want to do this wiring as CHEAP as possible..How cheap is Right???

Not picking on you..AT ALL JoJo..I'm just using your post to bring up points it seems I have to every 6 months or so..Please Don't take it that way at all..Being Safe is First and Foremost! I just wanted to point that out using this post.!

For your system, I would advise, save up your $$ and get a kit..a Basic Starter kit is only about $200..and you know what you have..no guessing..

Do a proper conversion, Sounds like you have about 90 % of the parts required now..Get rid of that unfused Split buss sysem..(I really hate those..what happens if you accidentally hook a 6 volt device into a 12 volt buss with NO FUSES?...)

As far as switchgear, Inspect your old, clean and test them, If the contacts are good and they clean up well, use them..They don't really care about the voltage on a low voltage DC system..

It is the contact rating in amps you need concern yourself with..going from 6 to 12 volts, if you didn't add higher draw devices you should be fine..(Voltage increases as Current Decreases, and Visa Versa)

Any you need to replace, you have a bunch of options , from OEM to custom..just browse a few catalogs..

Get at least a fuse link on the main support wire (s) that power the cab up..OR disconnect the battery until you can replace the harness...

__________________
Aftermarket Solutions
Electronic & Electrical
Innovations

you're right Doc, I'm going to buy a harness for my truck, cause you're right I'll just be "flirting with disaster" staying with and trying to ,as they say,"making pork outa pig s###" I thank you for all the advice and help you've given me. I'll probably pester you again with more help, I hope you don't mind. JoJo

Doc here,

No sweat! Were all out here for you! even if we need to go through it step by step during your install!

Doc

__________________
Aftermarket Solutions
Electronic & Electrical
Innovations