The Stovebolt Site Forums The Shop Area The Electrical Bay Need Help Wiring HEI distributor

I've got a 350 Chevy engine that I am building to put in my 1929 1.5 ton Chevy truck. I am wondering if anyone here can help me with a wiring question. I need to know how to wire up the HEI distributor (which wire is the hot wire, which is the ground ect...). My problem is wiring from a one wire system to a four wire system on the distributor. I've done some searching on the web and can't seem to locate any schematic information to help me with this. Any help or direction would be appreciated.

Thanks!

I'm sure others will have more information but this is what I have:

I still have the 235. I'm using a S10 HEI distrubutor and external coil. The wire from the ignition to the positive side of the coil had a resistor. My instructions said to remove it. My distributor has two wires. One wire (pink) goes to the positive side of the coil and the other (brown) goes to the negative side of the coil.

Hope this helps.

The white wire goes to the ESC(Electronic Spark Control) connection on the ECM.
The ppl/wht goes to a reference voltage, also in the ECM.
The tan/blk goes to a easily accessable male/female plug that is disconnected to check timing and then on to the ECM.
The blk/red is grounded inside the ECM.

If none of this sounds right and I suspect it doesn't, you need an earlier HEI.
Look for one with a vacuum advance on the side and a "BAT" and "TACH" connection on the cap.

Thanks for your replies, you've been a great help! I am headed to the salvage to get another distributor.

ok colors ... I know I'll just ask advise, can't hurt.
I have an HEI that I'm getting ready to make the 'plug-in' wire up to the new wiring harness. It has an Accel top mounted coil. Because I am not familiar w/ Chevy stock color codes what are the three wires at the dist:
black =
brown =
pink or beigh =
These three plug into the Accel coil w/ two other vacant plugs (wire leads) that are in the cap, BAT and TACH.
The BAT must go to the ignition post of the key switch ??? because the coil is 'internal' (mounted on top), the key switch supplies the voltage to this unit. ??
So while you answer I'll go open it up and see what's what.
Is this a possible tach feed wire?
thanks for the input
gooday
jim

yup...that goes to the ign switch.. the other is for a tach the old HEI only needs one wire,,,not resisted that goes to the switch.....uhhhhh on the four wire cap.. uhhhhhh if its like this from the front of the engine lookin down on the top of the cap like this
II
II
if thats the four wires then the ign goes to the top right one....hows that..???

Fatweed are you suggesting that the four wire type can be run with just the ignition connection? I've never played with one that new...

yup if i remember right...im sure its that way... the other two wires were for sumthin unrelated.. like some computer monitor or something,,,cant remember.....

The 4-wire distributor without the vacuum advance needs a computer to work properly, and a couple of inputs from places other than the distributor. The electronic spark control distributor does not have centrifugal or vacuum advance, and I don't know of any way to make it work on a non-computer engine. On the one with the mechanical advance, just put 12 volts to the "Bat" terminal on the cap, with at least a #10 wire from the ignition switch to the distributor. The 3-wire plug from the distributor housing to the cap completes the circuit, so don't forget to connect that one!
Jerry

Thanks guys
I've been doing my home work but I still have one question that I can not find a good complete answer to.

posted 08-23-2005 01:42 AM
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Some info says how easy or one wire hookup about wiring an HEI to your truck and little about the related starter. Most times the starter does not enter into the info. The original wiring did not have a Bypass wire from the plus side of the 'ign' & coil to the starter 'R' post. This way the coil ''only in start mode'' has full 12volt positive at the coil. The standard wiring had a resistor allowing about 9 += volts to the std. points dist. /coil during operation. When wiring for an HEI it is suggested to use a larger size wire 10-14 ga. should be placed to the HEI 'BAT' from the key switch ignition post and remove the resistor wire. I have also found notes on eliminating the 'Bypass' wire from 'R' to coil when installing an HEI.
Comments please...
my truck has HEI installed ????????
WHICH WAY TO WIRE...
Have the 10-12ga. bypass @ (starter solonid R) and the 'IGN' @ ket switch OR
use the (my) 14gauge (I might change this to 10-12 but I'm also wiring a starter relay setup so 10 ga is overkill) wire that only runs to the starter (S) post and my key switch 'start' post, (eliminate the ByPass wire ??? which as i think about this, I rather like having that extra effort at starting only.

eliminate resistor wire !!!! which can be used (if applicable) for the idiot lamp on a three wire alt'r set up.


Then we can talk about the relay for this circuit.
I'm now in the process of wiring several sets of relays off a separate fuse panel to horn, hi/low lamps, starter, fog/driving lamps &??
the tricky part will be the relay to HIGH beams and killing driving lamps when in low. it should be fun.
gooday
jim

If the wire from the ignition switch to the coil is replaced with a correct-size wire, there's no need for a bypass. The only time there is voltage on that starter solenoid lead is during cranking, and there's already full battery voltage to the coil if you've eliminated the resistor. The reason for the larger wire is to minimize voltage drop due to the somewhat higher current draw of the HEI system. Rather than cutting the resistor wire out, I just insulate the end terminal where the old coil was, and connect the heavy wire as close to the ignition switch as possible. Any other circuits the resistor lead feeds aren't affected that way.
Jerry

The easiest way to hook up HEI is at the key switch. Pull all the original ignition wires out and run one new 10 gauge wire from the dash to the "Batt" terminal of the HEI. Under the dash hook the new wire to the ignition terminal of the key switch. Now take a short piece of the same wire and hook to the start terminal of the key switch, take the other end and hook to the ignition terminal. You now have 12volts in start or run. You need do nothing else. Joe

that's what I wanted conformation on
thank you gentlemen
I'll do that today
gooday
jim

Wiring the driving lamps to go off when low beams are on is easy. Wire one side of a relay coil to the low beam wire and the other side to the switched terminal on the driving lamp switch. Wire the relay common to +12V and wire the relay NO terminal to the driving lamps. The relay coil gets its ground through the low beam filaments except when they are on. The driving lamp switch should get its power from the ignition accessory terminal to prevent any current flow if you forget to turn the driving lights off.

Baldy