Need starter wiring advice
 

Hi
I have a 30 ford roadster with a 1960 Cadillac engine and GM turbo 350 trans. The Wilcap adapter requires a 66-99 MOPAR small block 2 bolt gear reduction starter. I started having starter trouble yesterday and by talking to the previous owner found out that it has gone thru 5 starters in 4 years. I've been told that the Mopar starters should have a relay and mine don't alsoi been told that it would be easier for me to use a ford relay. Any of you fellows have any info or input on this? And if I need a relay does anyone have a plain-simple wiring diagram that I could follow. I know that on the Ford one the battery cable goes to one side and other side to starter,but there is also 2 small terminals on the relay what goes from there? and where does the small wire from ign to starter go?
Any advice would be greatly appreciated
Thanks

You can use a Ford relay. The Mopar starters work exactly like GM ones, except they don't have the second terminal the older GM's had for "ignition bypass." Most Ford relays (with 4 terminals) have this if you need it. Ground the relay, the I terminal goes to coil + for ignition bypass, and the S terminal goes to the start signal from your key.

I don't know whether Mopar solenoids draw a lot more current than GM or not, but the alleged reason Mopar did this is to save the contacts in the ignition switch. IT IS ALSO how the system incorporates the neutral safety switch, so this is a concern. How are you doing this?

There are two ways to wire it.

One way is to hook the main battery cable to one big stud on the Ford relay, then run a big starter cable down to the Mopar starter, and wire both the big and small terminals together.

This is actually a legit way to do this, some IHC and other rigs with some Ford built and some GM built starters did just exactly that

The second way to wire, is more like original Mopar. Here, you run battery to one big terminal on the Ford relay, and of course you can use that as a junction for other power takeoffs. You run a big starter cable FROM THAT SAME stud on the Ford to ONLY the big stud on the Mopar starter.

Then you run a second wire about no 12 from the remaining large stud on the Ford down to the small (solenoid) stud on the Mopar.

I have no idea why you are going through starters, but in my experiences with the aftermarket, a lot of "stuff" doesn't fit right.

I wasn't aware of the fact that I had to run a wire from the coil. The coil is fed 12V from the ignition switch---do I have to change that?

This depends on your ignition switch, AND your igition system

1. Check your ignition "run" wire coming from the ignition switch, and see if it remains hot while the key is twisted to "start."

If it remains hot, AND if you have an ignition system which does NOT use a ballast resistor, then you need nothing else, as the ignition runs off "straight 12V" and will get juice during cranking

BUT

If you have an ignition system using a ballast resistor, then you need the bypass circuit, because when you crank, the starter pulls down the battery. If for example, your battery is a little down, the starter may drag it clear down to 10V. EVEN LESS will be getting to the coil for start. This is the very reason that for years and years, "The big three" + AMC used a resistor, bypassed during start.

Now, if you test your ign switch, and (Mopar switch) the "run" feed goes cold during cranking, you MUST hook up the bypass line WHETHER you are using a resistor or not, because the igniton simply will not get start voltage.