7T3C3TTZ07

73 C3 small block. I observed that the solenoid engaged (or sounded like it did) but the starter did not crank the engine. Assuming the 8-yr-old battery had given up, I replaced it. Proper starting was observed only twice. I also observed that some chipmunks have visited the engine compartment over the winter. At this point, I am only to start the car by push start. It makes for good route planning.

I plan to check wiring, starter relay, solenoid and starter as follows. Please check my plan. I'm interested in ideas and whatever I overlooked.

1. I propose to pull the starter out an have it bench tested if I can find a place to do that (Autozone?)
2. I will clean all connections to assure that there is good contact with all the battery and ground cables.
3. I have the original (i.e. 1973) wiring harness for the starter. Now is probably a good time to replace that.
4. A thread mentions that a failed alternator diode can cause symptoms like a weak battery. When I can get the car started the alternator puts out about 14.7 volts. Are there other things to check?
5. I don't understand how starter relays function. Does the relay power the solenoid to move the starter gear to the flywheel and simultaneously power the starter motor or does the relay just power the solenoid and the movement of the starter gear closes a switch contact to power the starter.

Thanks for the help.

Mrvettenick

Your starter brushes are probably worn to the point where the spring tension is not strong enough to make good contact with the armature, You usually get hit or miss cranking depending where the brushes contact the armature. A bench test will probably indicate a high current draw. If it's the original starter, it's not hard to replace the brushes and clean up the armature. The purple wire that is at the S terminal gets power from the ignition switch directly.in the start position. But if you hear the solenoid clicking then that circuit is OK.

ddsmith60

Try smacking the starter with a BFH (Big F'ing Hammer). Often, that jars the starter enough to get it to rotate. If that works then your brushes are worn and you need to get a new starter or have someone rebuild your starter.

chevymans 77

starter solenoid pulls 2 functions,
1st it plunges the starter drive gear into the flywheel prior to it spinning and 2nd it passes battery voltage to the starter motor to turn the engine over. There is a large set of contacts in the end of the solenoid that do burn up and get distorted from use. Some solenoids can be taken apart and filed but will usually fail soon after so its best to either replace the solenoid or the starter. It takes some trouble shooting to figure out what the root cause is then you can fix the issue.

Neal

HeadsU.P.

Before you pull the starter:
Take a picture of the wiring. You Will Not Remember How It Goes three days later. Make a drawing of the posts, if you have to. Label all small wires with masking tape & a Sharpie which post it connects to.

Note if there are any shims and under which bolt hole.

If you purchase a new Solenoid, get the unit with a brown end cap. Those are ceramic, a little more money but can handle the heat better.

Mrvettenick

If you decide to get another solenoid, make sure it's a Delco. Some aftermarket solenoids cannot be used with a shield, because where it mounts to the solenoid is not insulated.

derekderek

throw the starter out. buy one of these. https://www.ebay.com/itm/39116078469...Cclp%3A2334524 there are zillions from 40 to 400 bucks. way less weight held over your head while trying to thread the bolts. i did starters for a living and i won't mess with a 10MT.

7T3C3TTZ07

Thanks everyone for the prompt, informative and thorough advice. I enjoy working on this old car but I like to have a bit of a clue of where to begin. Regards, Ken

augiedoggy

this is what I did 7 years ago. Smaller newer starter works much better too.

7T1vette

The starter solenoid may 'click' to indicate that it has mechanically actuated; but that does NOT mean that any electrical connection has been made to the starter. A very common problem is that the contact disc inside the solenoid is damaged, covered with carbon, or is just worn out. So, I suspect that the starter solenoid is still the most likely cause of your problem.

7T3C3TTZ07

Derek,

I received the starter (ForeverrunAuto) that you recommended. I notice that it has one less terminal than the Delco. Described as follows:

I notice that on the old Delco there are four terminals on the solenoid portion: From top clockwise 1: Large Terminal for Battery Positive, 2: Small Terminal "S" for purple wire that connects to ignition switch via neutral safety switch, 3: large diameter terminal with wire already connected to starter, 4: small terminal labeled "R" for red wire to coil positive.

The ForeverunAuto solenoid has three terminals: 1: A large terminal with nothing connected. I assume that is for the battery positive. 2: A small terminal that is not labeled. I assume that may be for the purple wire. (formerly the S terminal). 3: A large terminal with a large gauge wire going to the starter. I assume nothing more is connected there.

Where should the coil positive be connected? The one formerly attached to the R terminal.

Thanks,

Ken

HeadsU.P.

Are your starter mounting bolts staggered or straight across from each other.
How many teeth on your flywheel?
The extra post on some solenoids I believe is for the old points & condenser IGN system. I didn't see a '73 listed in the app listing.
Do you currently have a bracket from the starter to the block for extra support?

7T3C3TTZ07

HeadsU.P. The mounting bolts on the original starter and the mini-starter are staggered. The engine is 1973 original. That is, it has the original points distributor and, I assume, the flywheel has168 teeth. The webpage asked for the year and make but may assume. It may be that the mini starters assume an upgraded ignition. I do have an extra bracket for support of the starter (at the front) this also supports a heat or dust shield.

7T1vette

Still planning to toss money at a starter, eh....?

Mrvettenick

That 4th terminal is an ignition resistor wire bypass for easier starting. It eliminates the primary resistance in point systems for a hotter spark when starting.

HeadsU.P.

7T3C3TTZ07,
I have come to the conclusion over the years that some posters on here will do anything to save a buck. I also feel that these people enjoy breaking down and replacing parts with NOT better ones, but just another crap part. They enjoy this so much they are willing to do it every few years.
The parts that are bought cheap over & over are batteries, power steering pumps, junkyard heads and . . . . . . . . . . . starters.

In my opinion and maybe only mine, you will not be happy buying any starter under $150. (just short-lived, disposable junk)

Mrvettenick

There's no guarantee that if you buy a more expensive part, that it will outperform the cheaper part. I'm not a big aftermarket guy,

HeadsU.P.

That's true. But the odds are in your favor.

And it doesn't have to be aftermarket either. I am referring to quality parts vs junk parts that will leave you stranded at the worst possible time.
It boils down to this. Which is the better replacement?
A $50 part every two years?
Or a $200 every ten yrs?

Mrvettenick

There's no substitute for quality, but there's so much crap out there, it's easy for someone to be misled. Let the buyer beware.

HeadsU.P.

Bingo !!!!