So, I want to hook up a mini starter I purchased from Ecklers a couple of years ago. I believe it is a Powermaster. I searched and viewed a few threads. Quick electrical question on the diode. Radioshack only had a 1A 400 PIV. I believe Powermaster states use a 3A 400PIV. I don't know much about wiring.

1. Can I use the 1 A or do I need to go ahead with the 3 A?
2. Also it would appear I connect one end of the diode to the solenoid terminal that connects the solenoid to the starter. Do I connect the "R
(resistor) wire to the the other side of the diode?

Thanks!

 

If they specify a 3 amp diode, then you must use at least a 3 amp diode or bigger. Same with voltage rating. They specify 400 PIV, so you must use at least a diode rated at 400 volts or higher.

That is not to say that a lower rated diode would not work, but it would not be reliable and could strand you at the wrong time (in this case, if it failed, it would not supply full voltage through the diode to the ignition, making the vehicle harder to start). If the diode failed, you might never know, since the vehicle can start through the ballast resistor, but is not receiving full voltage due to the ballast resistor voltage drop. Under a weakened battery or harder starting condition, that coil needs all the voltage possible (and the starter is drawing down that voltage with every crank).

Did they supply a diagram / schematic showing how the diode is to be hooked up? If not, and you still have questions, give them a call. Note that the diode must be inserted into the wiring in the correct polarity. It is polarity sensitive with the end with the white band being the negative (cathode) end, and should be attached to the wire that goes up to bypass the ballast resistor (the wire from the starter "R" terminal), and the opposite end (the anode end of the diode) is connected to the terminal on the solenoid which has the cable from inside the starter motor connected to it. It is opposite the BATTERY terminal on the solenoid.

Plasticman

 

Rat Shack 3 amp, 400 volt diodes.

http://www.radioshack.com/product/in...ductId=2062579

 

Don't worry about the PIV rating, just the amps is important. Also keep in mind that the diode when conducting will drop about 0.7 volts...usually not important

 

Thanks for the quick responses.

I'll get the 3 Amp.

 

interesting.... i didn't have to use a diode with mine....



Bill

 

I am sure they specify the 400 PIV rating to prevent inductive kickback from breaking down the diode.

Plasticman

 

Bill,

This is from the Powermaster website. They specify a diode, if bypassing the ballast resistor. And they are correct, since if you just connect the "R" wire up with the existing starter wire, you will be feeding ignition "run" voltage through the ballast resistor to the starter while running - in other words, a diode is needed to prevent backfeeding the starter from the ignition. You did not need that bypass since you had the Accel EFI and Dist. by that time (you were trying a new starter because the Accel dist was not clocked properly and was causing hard starting).:


What do I do with the wire that went to the "R" terminal on the original starter?


In early original wiring harnesses, the "R" circuit was a ballast resistor bypass. This terminal is no connection when the starter is at rest, and is +12VDC while cranking.This circuit provided +12VDC to the ignition coil during cranking for easier engine starting. Cars that do not have a ballast resistor (i.e. HEI, MSD, or other aftermarket ignition systems) should not need this connection. In most cases, this wire can be eliminated. If the engine has no ignition during cranking, then the wiring of the coil is going to require an "R" terminal signal. To accomplish this, connect a 3A/400PIV diode (or Powermaster part # 600 ) in line with the MOTOR SIDE of the solenoid. (Note: This is the terminal on the solenoid which has the cable from inside the starter motor connected to it. It is opposite the BATTERY terminal on the solenoid. The cathode or banded end of the diode goes away from the starter. This allows current to go from the starter to the coil and yet not from the coil to the starter.)

John