I have installed a GM one-wire alternator and electric fuel pump. I removed the voltage regulator. I am not such about the wiring. I have the original wire diagram from the manual and conversion instruction for generator to alternator, but no specific wiring instruction. I need basic wiring help. Is there any help out there?

 

What are you trying to figure out exactly? I can help with specific questions you may have. The fuel pump should be connected to a source that turns on and off with the ignition. A relay is usually a good device to use so you do not add an additional load on the system. I would hook the fuel pump up to a relay that you can buy from an autoparts store for around $3.00. As for the other wiring if it were mine I would remove the tape from the harness take out the wiring that is no longer used and tape it back together. Does your truck have points? Have you changed the lights over to 12 volt lights? How about the gauges have you connected a voltage regulator to the gauge power to lower the voltage to 7.0 volts or close? If you are going to a negative ground from a positive ground you will need to reverse the wiring on the ammeter so it does not work backwards.

 

I agree with removing the voltage regulator wires from the harness. When I did mine, I labled all the connections, removed the harness from the truck, and pinned it to a sheet of plywood, with the harness spread out in the basic shape it would be on the truck. That way I was able to remove the wires to the old regulator, and add the new heavy 10 gauge wire from the altenator into the harness and ran over to the positive side of the battery or starter selenoid. Don't forget a resistor to the coil, with the cover off the harness you can add extra wire to put in the resistor and mount it to the inner fender or wherever you want. Re-wrapped the whole harness with tape and it looks pretty decent. Also made it very easy to inspect all the wiring for any defects or damage, replace loose ends, etc. Be neat about it and use some heat shrink tubing if splicing wires or covering new ends. Man I love that stuff.

Scott

 

I failed to mention I also have replace my coil with a 12 volt unit. So the resistor would not be necessary? I am a real novice at this wiring stuff. Shouldn't the hot lead for the electric fuel pump come from the ignition switch? I believe is need resistor for the dash hot lead. thanks for the help

 

Lessee if I can keep this short and still get it right. In a 12V system (don't know about the older 6V systems), the coil is designed to operate on about 8V or so.

Under normal running conditions (the starter motor is not engaged), a resistor is included in series with the coil so that about 4-5V is dropped across the resistor, and the remaining 8V or so is across the coil. The coil is happy and puts out a good spark.

While starting, the starter motor draws a big current and the battery voltage drops to somewhere around 8V (lower when it's cold). If the coil were designed to run on 12V, you'd get a very weak spark when starting the engine. The ignition wiring is set up so that the resistor is removed from the circuit during starting, and the entire available battery voltage is used across the coil. The coil is happy and puts out a good spark.

The starter solenoid is used to switch the coil resistor in and out of the coil circuit. If you look at the black box in the upper-left of the schematic below, you'll see the coil is powered by the wire on the right side of the circle representing the coil. When starting, power comes to the coil through the wire labeled "To Starter Relay" and is the full available battery voltage with the starter engaged (around 8V). When not starting, the "To Starter Relay" wire is disconnected at the starter solenoid, and power comes to the coil through the resistor from full battery voltage (12-13V).

 

A external resistor is still necessary with 12Volts or the points and condenser will "fry"

 

Buddy I have wired several old cars and trucks over the last 40 years. I always did them from scratch, just a few weeks ago I installed an EZwire harness in my 51. That was a pretty intense experence for me using a harness confusing at times. You say your novice at doing the wiring. Most important of "all" be sure your truck has the FUSABLE LINK installed in it. That way if you mess up, the link will blow and save the wiring possible the entire truck. If you know any experienced people that can help you I would give him a call

 

Buddy,

The one-wire is pretty easy as far as charging systems go. Depending on the output of the alternator use either an 8-10 gauge wire from the bat terminal on the alternator back to the positive side of the battery. Depending on what kind of starter setup you have the starter solenoid can be a good place to tie it in to the positive side. The electric fuel pump should be powered off a source that is hot only when the key is in the on/start position. Run it through a 20 AMP fused circuit or use an inline 20 AMP fuse. Hope this is of some help.

Vern

 

Thanks for all the good info. Looking at the wiring diagram, I have removed the generator and the regulator, if the #10 Y wire that was connect to “B” of the regulator was connected to single output of the alternator (understanding the wire should be replace with a heavier gauge) would this do the job. In the diagram, is the resistor you are speaking about the resistor shown between the ignition switch and the coil in the inset box?

 

Yup, assuming you have a one-wire alternator, you've got it. Rated current capacity for 10 AWG (American Wire Gage) wire varies from 15 Amps to over 55 Amps, depending on the installation. In an automotive installation, where it will be part of a harness, I like to derate it a little and avoid going over 40 Amps. For 8 AWG wire, the limits range from 24 to 73 Amps. I derate it to about 60 Amps. If your alternator can put out more than 60 Amps continuously, use 6 AWG and you're safe up to 85 Amps or so. Make sure you use automotive wire, not THHN or similar premises wiring.


You're right on this as well.

 

Go to bounsbuilt.com Gives all the details. Did my f1 in about 2 hrs. Good luck, Tim

 

Here's the link for Bonusbuilt.
http://www.bonusbuilt.com/12.html
I went with the "runtz" voltage reducers on my guages (oil press, temp, and fuel). Don't forget you need to run the wire through the ammeter the opposite way when you change polarity.
On the ballast resistor:
First I had an internally resisted coil that lasted about 100 miles. After I put in a regular coil I went to a high quality set of points like we use in our old oliver tractors that we converted to 12V. No ballast resistor. I can't recall the name of them but I got them from a local tractor mechanic who does these conversions all the time. I keep a spare set of points in the truck but these have gone about 2000 miles with no problems. Don't bother trying this with cheap points. They won't last. Good luck. John

 

JDMICK, If that engine is a Flathead 226 Could you please find out the brand and possibly the supplier for those points. I would like to purchase a set or two.

 

My engine is a 239 V8 but the parts catalogs list the same points for the 48-53 V8 as the 48-63 six. I'll get a hold of him next week to find out the brand. John

 

Well I finally got the info on the points. They use an extra copper or brass strap that runs with the usual metal spring. This reduces resistance and therefore heat. The brand is Blue Streak made by Standard. The part # is FD8183XV. They come in a blue and black box. John.