Starter wiring woes
 

428 swap continues. 69 Firebird.

Old 350 had points.

428 has HEI

Starter causing a headache. I have the main positive wire coming from battery to big middle post. I have 2 other wires coming from above. One is smaller and looks purple. I assume that’s the S wire. What about the other wire? Was that the R? Should it be deleted? I’m wondering if it goes with the positive wire? I have no power in the car. None anywhere.

The battery cable goes to the big post along with that bigger wire that has the big hole connector. (that should be the power to the alternator)
The purple wire is for the 'S' terminal for the starter circuit.


:)

There you go. The second wire with the large ring terminal goes to the large starter bolt along with the large battery cable. As mentioned above. It's the main power feed to the entire harness.

George

The R terminal gets no wire any more since you do not have points.

That wire was used to bring a full 12 volts to the spark coil only during cranking for a hotter spark.

This is good info. My 69 Lemans has points and a Powermaster mini starter that only has two posts. Gotta see how I connected it…

You guys nailed it as usual. Working perfectly. Needed 4 shims but other than that…. Onto next part.

Regarding the "R" terminal, AFAIK, firebirds used that terminal for resistance bypass during cranking, A bodies did not use that terminal, at least on a '67.

George

I previously had points... but the R wire was not in use. Go figure. Not sure about that but not uncommon when you work on these cars. At some point in the past someone made a change. It has probably had 3 starters installed by 3 different mechanics.

Thats the part that was throwing me off. I was expecting an R wire and there wasn't one. For whatever it is worth I wasn't having issues with the starter previously.

You can use the 350 points distributor in the 428. Some of the members prefer it. The points require ~9 volts during normal running. However it requires full battery voltage 12-13 volts to start. Of the two wires in the first pic one is the feed from the ignition switch. Probably the larger, it should be purple; hard to tell in the pic. The other is the 12v supply to the coil. Typically one of the two terminals on the coil will have two wires connected. One 9v resistor wire from the ignition switch, the other the 12v wire from the starter solenoid. The other terminal will have one wire connecting to the dizzy. When you install an HEI it will need 12V at all times. Wiring modifications are required.

The coil has already been deleted at this point. But that wiring was from when there WAS a coil. The two don't seem to match. I don't really care because everything is working correctly now but I'm not exactly sure how it was working correctly before.

I am running a new ignition wire directly from the fuse box to the HEI.

~
 

COMMON mistake. There is no "12V" power to the (points) ignition at any time. When the starter is cranking, SYSTEM VOLTAGE drops to 9--11 volts due to the enormous amperage draw of the starter motor.

So when the engine is running, alternator output may be as high as 15 volts, but the ignition system gets ~8 to 9 volts due to the ballast resistor. When the engine is cranking, there is no alternator output, the ignition system gets 9--11 volts due to the system voltage (battery) being dragged down by the starter motor draw.

10 or 12 gauge, no ballast resistor...right? The HEI runs on 8--18 volts, although I suspect more than 16 volts would be a short-time deal, not long-term. The goal was to keep the ignition system protected if the alternator failed in a way that produced maximum voltage, and the alternators of the time could not make more than about 18 volts.

True enuf.

George

Please excuse me for highjacking the thread. During cranking does the ballast resistor further reduce the ignition system from the system voltage of 9-11? When switching from points to HEI, one of the wires on the solenoid is deleted. The one left is the energizing wire from the ignition switch. This results in starting woes as the mistake is in leaving the points ballast wire to supply the HEI, which does not provide sufficient voltage for starting. Before I learned about the ballast wire., I always had much difficulty in starting the engine. However, once the engine was started it ran just fine on the ballast wire. I should have just stated that the second wire from the solenoid supplied system voltage to the points (for easier starting) as opposed to 12V. Once I deleted the ballast wire and used system voltage (as opposed to 12V) for the HEI I had no more starting troubles.

When using HEI on a previous points-distributor car, there should be a wiring mod to provide system voltage to the HEI during crank and run modes. On A bodies, this is as "simple" as using a bypass wire across the resistance wire in the harness. "A" bodies source two circuits from the ignition switch, IGN1 and IGN2. IGN2 is the cranking source. IGN1 supplies power thru a resistive wire, once the engine starts and the key is released. These 2 wires are usually connected together at the ignition coil. On cars using the R terminal the same action is done but there is no IGN2 from the switch, the R wire provides power during cranking, and this wire is combined with the run (resistor)wire at the coil.

The HEI may operate ok thru the resistor but it is not optimum. The electronics are designed to operate at low voltage such as may be present during cranking at low temperatures, but should operate from normal system voltage; cranking thru a ballast resistor will lower HEI voltage even further.

George