Olds 403 wiring
dolfins1a
05-02-2005, 09:04 PM
I have a complete 403 sitting on a test stand with no wiring at all. Anyone know how to wire this engine to test run it. (Alternator, Distributor and Starter). Any help would be greatly appreciated
MagicRat
05-03-2005, 07:11 PM
The wiring depends on the distributor you have. Stock, these engines came with an HEI distributor. It is large, with an ignition coil built into the cap.
If you have this, it should have a 2 wire plug on the side of the cap pointing down, with two blade-type electrical connectors. One should be market positive. A 12 volt wire switched (to the ignition) should go here. You can use a simple toggle switch to turn on the 'ignition'
The other wire should be labelled TACH and is the negative terminal for an electric tachometer. It is not used unless you want to hook up a tach.
The starter is easy. The solenoid sits on top of the starter and has one fat threaded terminal on it. Attach the thick 12 volt positive wire to this terminal and run the other end directly to your battery.
There will be another very small threaded terminal beside it. This activates the starter and should only receive power when you want the starter to crank over. Attach a small 12 volt positive wire to this terminal. Use a push button switch on the wire, so it only gets power when you push the button.
The engine will run on the battery power alone without any alternator hook up. However, if you wish to hook up the alternator.........there should be a small threaded terminal on the back of the alternator, which is insulated from the alternator housing with a plastic gasket. Hook up a relatively thick wire to this (10 gauge or thicker) and connect it directly to the positive terminal on the battery.
The alternator will have a socket on the side which accepts a 2 bladed plug. The two electrical blades are labelled 1 and 2. Blade 1 MUST be hooked up to the positive terminal on the ignition toggle switch, so it only receives power when the ignition is ON. Also, it MUST have a 10 ohm resistor hooked up between the blade connector and the ignition switch. In the past, I have used a Radio Shack 10 ohm one amp ceramic resistor. However, many GM applications use a light bulb (like the kind that is used on dashboard idiot lights) with a similar resistance. This resistor is what alows the voltage regulator inside the alternator to work. Often, if the alternator fails, this light bulb is illuminated.
Blade 2 is hooked up to a 12 volt positive source. The toggle sitch for the ignition will do fine for this.
Finally, use a thick wire bolted to the engine block and connected directly to the negative terminal on the battery.
Good luck.
If you have this, it should have a 2 wire plug on the side of the cap pointing down, with two blade-type electrical connectors. One should be market positive. A 12 volt wire switched (to the ignition) should go here. You can use a simple toggle switch to turn on the 'ignition'
The other wire should be labelled TACH and is the negative terminal for an electric tachometer. It is not used unless you want to hook up a tach.
The starter is easy. The solenoid sits on top of the starter and has one fat threaded terminal on it. Attach the thick 12 volt positive wire to this terminal and run the other end directly to your battery.
There will be another very small threaded terminal beside it. This activates the starter and should only receive power when you want the starter to crank over. Attach a small 12 volt positive wire to this terminal. Use a push button switch on the wire, so it only gets power when you push the button.
The engine will run on the battery power alone without any alternator hook up. However, if you wish to hook up the alternator.........there should be a small threaded terminal on the back of the alternator, which is insulated from the alternator housing with a plastic gasket. Hook up a relatively thick wire to this (10 gauge or thicker) and connect it directly to the positive terminal on the battery.
The alternator will have a socket on the side which accepts a 2 bladed plug. The two electrical blades are labelled 1 and 2. Blade 1 MUST be hooked up to the positive terminal on the ignition toggle switch, so it only receives power when the ignition is ON. Also, it MUST have a 10 ohm resistor hooked up between the blade connector and the ignition switch. In the past, I have used a Radio Shack 10 ohm one amp ceramic resistor. However, many GM applications use a light bulb (like the kind that is used on dashboard idiot lights) with a similar resistance. This resistor is what alows the voltage regulator inside the alternator to work. Often, if the alternator fails, this light bulb is illuminated.
Blade 2 is hooked up to a 12 volt positive source. The toggle sitch for the ignition will do fine for this.
Finally, use a thick wire bolted to the engine block and connected directly to the negative terminal on the battery.
Good luck.
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