[bulletpruf]

Ok, so I have a 455 that I built for my 1968 Lemans convt. It's a strong pump gas motor with moderate compression (9.5:1 or so).

It was off the road for a few years while I was finishing up a tour with the Army a few thousand miles away, and now that I've dusted it off and gotten it running again, the starter motor is definitely not happy. It doesn't spin over very fast, and when it does, I get the rapid clicking from the starter, so it does not seem like the starter is getting enough voltage.

Starter itself is just a stock unit.

Battery is new and fully charged.

My plan at this point is to change the battery cables to something thicker. The cables were new when installed a few years ago, but they're just basic stock cables.

What size cable should I go with? Looks like the stock stuff is 4 AWG (gauge), so I'm thinking 2 or 1 AWG. I plan to buy bulk cable and build them myself using crimped lugs, heat shrink, and military terminals. I have some 2/0 cable (not 2 gauge; much thicker!) left over from a 7.3 diesel job but that seems really thick for this application.

Thanks,

Scott

[Goatracer1]

If you have low compression you shouldn;t need thick cables. I would check the battery ground on the engine block, Could have rusted while you were away. Also the connection of the starter to the block. Remember just because it was a new battery doesn;t mean it;s good. Check the date code on it. I;ve seen them on the shelf a couple of years old.

[78w72]

x2 thinking its not a cable issue, i use stock cables on the same comp 455 for 10+ years with no issues.

I would check/clean the connections & grounds first, then look at the starter itself, especially the solenoid. Have had bad solenoids act the same way.

[bulletpruf]

Originally Posted by 78w72

x2 thinking its not a cable issue, i use stock cables on the same comp 455 for 10+ years with no issues.

I would check/clean the connections & grounds first, then look at the starter itself, especially the solenoid. Have had bad solenoids act the same way.

I checked all the connections and grounds. I thought the ground on the cylinder head might have been the problem because it had some corrosion, so I cleaned it up with a wire brush and sandpaper and re-assembled with dielectric silicone grease and no change - still clicking.

I just had the starter and solenoid off (I removed it when I pulled the trans) and all looked nice and clean and fresh as I reinstalled.

It would be easy enough to pull the starter and replace the solenoid and double check everything. I don't want to load up the parts cannon unnecessarily, but no big deal if I end up with a new solenoid.

I think I'll still replace the cables with 2 gauge. Won't cost much and that'll give me an excuse to use my fancy crimping tool.

[bulletpruf]

Also, how can I check to see if the purple wire is working? Can I hook the starter up (without bolting it to the engine) and have someone bump the key while I'm holding a test light to the S terminal?

And any ideas on how to confirm whether it could be the neutral safety switch? This car has a floor shift automatic trans; I'm guessing its on the shifter mechanism, right?

Thanks

[Dragncar]

Originally Posted by bulletpruf

Also, how can I check to see if the purple wire is working? Can I hook the starter up (without bolting it to the engine) and have someone bump the key while I'm holding a test light to the S terminal?

And any ideas on how to confirm whether it could be the neutral safety switch? This car has a floor shift automatic trans; I'm guessing its on the shifter mechanism, right?

Thanks

You check the purple wire just like you said. If it gets hot when you turn the key I bet its your neutral safety switch.
If you bench tested your starter/solenoid combo and it turns over and the Bendix kicks out the starter drive there is only so many things that can be wrong with it.
Bad ground, purple wire is getting no power due to bad ignition switch or that N/S switch.
If its a N/O switch, normally open and makes contact when in park or neutral you could jump that switch.
But then it starts in any gear.
Bet its you N/S switch or its connections.

[BB70]

Originally Posted by bulletpruf

Also, how can I check to see if the purple wire is working? Can I hook the starter up (without bolting it to the engine) and have someone bump the key while I'm holding a test light to the S terminal?

And any ideas on how to confirm whether it could be the neutral safety switch? This car has a floor shift automatic trans; I'm guessing its on the shifter mechanism, right?

Thanks

Instead of a test light, get a fog light bulb and use jumper wires, one to the purple wire, one to a good ground. A fog light bulb will work the circuit, nice blinding light is what you want. You can even make the jumper wires long and put it on the cowl so you can see it from the seat. To test the neutral switch unhook it and jumper wire the wire connector and turn the key, check your light. Good jumper wires are your friend.

[bulletpruf]

Originally Posted by BB70

Instead of a test light, get a fog light bulb and use jumper wires, one to the purple wire, one to a good ground. A fog light bulb will work the circuit, nice blinding light is what you want. You can even make the jumper wires long and put it on the cowl so you can see it from the seat. To test the neutral switch unhook it and jumper wire the wire connector and turn the key, check your light. Good jumper wires are your friend.

Thanks, good info.

Scott

[george kujanski]

Low battery or poor battery connection...including the ground side. Make sure the batttery terminals are clean/tight.

George

[bulletpruf]

Originally Posted by george kujanski

Low battery or poor battery connection...including the ground side. Make sure the batttery terminals are clean/tight.

George

It's possible that I have a bad battery. It's fully charged, but I haven't load tested it.

Terminals are clean and tight.

[Shiny]

My new battery sat for about 5 yrs without a trickle charger and it died.

Suggest you haul your battery to the parts store and get it tested.

That is a really nice color combo.. pretty car!

[bulletpruf]

Originally Posted by Shiny

My new battery sat for about 5 yrs without a trickle charger and it died.

Suggest you haul your battery to the parts store and get it tested.

That is a really nice color combo.. pretty car!

The battery is only about a month old, but it will only take a few minutes to yank it and bring it to the nearest parts store for testing.

Thanks

[Shiny]

Woops, sorry I assumed...

Yes, seems unlikely to be the battery. What George said.

[bdk1976]

I fought starter issues for years on my 65 - last year I put in a mini starter using 1/0 wire and military terminals and zero issues since.

[bulletpruf]

Originally Posted by bdk1976

I fought starter issues for years on my 65 - last year I put in a mini starter using 1/0 wire and military terminals and zero issues since.

What mini starter did you use? What engine and compression?

Thanks

[Shiny]

Progress!

If you clean up all the connections like you did and still have an issue, the solenoid is where I'd look next.

Greg is on the same path...

As to the cable, a bigger one might help, but make all the connections good first. A new cable might, however, fix a couple bad connections!

A voltmeter with some long test leads could sort it out pretty fast if you're comfortable using one.

[bdk1976]

Summit mini starter - low compression '73 455 (~8:1)

[Greg Reid]

Check the voltage on the purple wire coming from the ignition switch to the S terminal on the solenoid while someone turns the key. That wire gets baked over the decades and will develop resistance giving you low voltage to the solenoid. I had to change mine out for the same reason. I didn't bother the ignition switch, just spliced in a new wire from the firewall to the S terminal.
By the way, I switched to a mini starter also. It did the same thing and that's when I started diving deeper and found the low voltage situation on the solenoid wire. IMI is the brand I used because I like the terminals on the side opposite the exhaust manifold.

[george kujanski]

To diagnose if you have a purple wire problem after the battery terminals are clean and tight: add a wire to the solenoid terminal and use it to jump directly to the battery. If it works better, the purple solenoid wire has an issue. This connection goes from the battery thru the firewall, thru the ignition switch, thru the park switch (auto trans) then to the solenoid.

A good opportunity for poor/worn connections over time.

I had a problem on a car that had the battery in the rear section (Caddy Allante) that began to have solenoid issues so I added a relay in the solenoid circuit to shorten/ eliminate the long OEM connection. Problem solved. Then again the car has an Italian electrical system....'nuff said!

George

[bulletpruf]

Originally Posted by george kujanski

To diagnose if you have a purple wire problem after the battery terminals are clean and tight: add a wire to the solenoid terminal and use it to jump directly to the battery. If it works better, the purple solenoid wire has an issue. This connection goes from the battery thru the firewall, thru the ignition switch, thru the park switch (auto trans) then to the solenoid.

A good opportunity for poor/worn connections over time.

I had a problem on a car that had the battery in the rear section (Caddy Allante) that began to have solenoid issues so I added a relay in the solenoid circuit to shorten/ eliminate the long OEM connection. Problem solved. Then again the car has an Italian electrical system....'nuff said!

George

I see you live in Palatine; small world. A good friend of mine from college is your Police Chief.