Technical Starters Question

What is that attachment from the starter to the solenoid ? I might have wired the new starter wrong. It's a Chevy starter and I connected the purple ign. switch wire to the S terminal but after getting it installed I can turn the Ign. switch and the starter does nothing like the batt. is dead, if I keep moving the key it does turn over a couple of times but then back to nothing again. I really can't remember if that purple wire went to that bottom attachment or not. Thanks Everyone

 

you have to use purple as trigger wire to solenoid and the other one as reistor by-pass on the other term

 

What other wires do you have? IGN. on the starter is ignition ballast bypass in crank position. Should go to the coil. S term on starter should go to S on ign switch. That loose screw on the bottom of the solenoid is a big problem as well.

 

Yup, that long screw that goes through the spacer, is what carries the current from the solenoid to the starter windings. If it's loose like that, it won't work very well...

 

I have installed a new starter, The picture is of the old one I loosened the screw . The problem started after I installed the new starter that's why I thought maybe that purple wire went to that lower attachment instead of the S term.

 

Always bench test a starter before installing it .
Some jumper cables and a piece of wire is all you need.

It saves a lot of grief.

On the solenoid "S" goes to the ignition switch and "R" goes to the coil.

 

Thanks for the picture, I do have it wired correctly then. Now to find out why it acts like the batt. is dead and if I continue to turn the key on and off it might turn over a few times but then go back to acting like a dead batt.

 

Sounds like a poor connection somewhere. Battery connections, chassis grounds??

 

Run a jumper cable direct to the starter [main cable] then try it.
Then a jumper cable direct from neg battery to the engine [ground cable] then try it.

Then try and short the "S" with a screwdriver or another piece of wire

That is why I bench test first [to eliminate the starter as a problem]

 

Not sure about how to short the S connection post ?

 

feed it

 

The ignition switch may be bad, or have a bad connection.

 

What has me stumped is the car would start but it had a bad starter that had some worn teeth on the starter gear. So that's when I bought a new starter installed it and this story started.

 

This is a perfect case where conducting voltage drop testing will pinpoint the problem. Do you have a digital voltmeter?

 

No, on the voltmeter.

 

You're gonna want to pick up a DMM (digital multimeter) before you get too far down this rabbit hole. You can get a passable unit pretty reasonably priced. Bonus if it is an "automotive" unit that has dwell and such as you may need that in the future. I grabbed one at Menards recently for $30 or so. No, it's not a heirloom (fluke), but it tells me what I needed at the time.

Check voltage at the battery to make sure you have 12 or so.

Then I work backward from the starter, personally. Unhook the sire from the S terminal, and run a temporary wire from that to near the battery. If the starter turns the engine over when this wire touches B+, then something is bad between the S terminal and the battery.

Now connect your DMMs + lead to the factory S terminal wire and the - lead to ground (B-, the engine block, etc.). Set the DMM for DC voltage. See if your meter reads 12V when the ignition switch is turned to the Start position. If no voltage there, check the wire feeding the ignition switch for battery voltage. Keep working your way back from component or splice until you find where you have battery voltage.

If you have voltage to the ignition switch input terminal, but no output, you can disconnect all of the wires from the switch and use the resistance (Ohms or Ω) mode to see if there is continuity between the input (battery) terminal and whatever terminal feeds the various wires.

Early automotive electrical systems aren't super complicated. If you can find the wiring diagram for your car it makes it even easier. Take your time and be methodical. This will keep you from being one of those "pluck and chuck" guys who just swap out parts without knowing why or even if said part may be bad.

 

Great advice, Thank you !

 

Bad solenoid on the new starter. Bet if you swapped the solenoid from the old starter to it the starter will work. But really should just take it off and return it for warranty.

 

I just took the starter off and bench tested it and it worked great, I know a starter is grounded when it's bolted to the engine but I noticed it looks like it has an aluminum mounting block , Does this somehow need a ground to the engine ? If not I'm thinking maybe the ignition switch may be bad ?

 

Go to Harbor Freight and get a cheap digital voltmeter then you can test and not guess.

 

Use a screwdriver across the Main Feed and "S" terminal
like this.



Not that I know...... But the rumour is car thieves have been doing this for years [before steering locks and slide-hammers]

You can test the starter in place with a piece of wire with 2 alligator clips.
But do as what @jaracer suggested and buy a cheap H/F multimeter [you should have one in your arsenal anyway]

On our 57 Chevy there was 12volts at the "S" wire but it barely cranked [similar to heat soak issues]
Load testing showed almost zero current.
It turned out to be a melted wire between the Ign switch and firewall under the dash.
This was surprisingly easy to replace / rewrap [from the firewall side]

Do a voltage test on the "S" purple wire [red to purple and black to ground]
If no voltage that is your problem.

If there is voltage, then select Amps "and use the correct posts on your multimeter"
Then connect these in-series with the "S" terminal and "S" purple wire [so the load goes through the multimeter] then try and crank it.
This will show you Amp draw.

One last thing , make sure the battery ground wire is connected directly to the engine block [and a secondary ground to the body]
GM used star washers under the ground and main 12v feed cables

 

Yes the battery neg. is attached to the engine. Iv'e already determined the starter is good by the bench testing so your saying I'd be checking for a bad wire or the ignition switch ?

 

In your bench test of the starter, does it spool up to speed, or torque the starter over? It should torque the starter over.

 

It can also be the main 12v H/D cable from the battery to the starter. But a quick "short" with a screwdriver will confirm/eliminate that.
If that is OK and you test the purple wire and it appears to be a problem. Then unplug this from the Ign switch and measure resistance of the whole wire [from each end]
The resistance should be close to zero.

I've made up a few wires with Male / Female spade terminals on each end so I can power up the Ignition switch with the main plug removed. [connect the 12v feed "in-series"]
You can go through the switch spade terminals with the multimeter checking for 12v when on ,and cranking position "S" .

Apart from wires being melted near the switch, the other problem I've encountered was dirty connectors which I clean.
A fine scotch pad soaking in Isopropyl alcohol gets them clean

I give the male spades on the back of the switch about a 3° twist with needle nose pliers.
This is enough to pre-load the terminals for a good connection. [ because sometimes the females are loose in the plastic plug]

 

Also if using a screwdriver or even a wire to jump at the starter try to not touch the studs as this can and will damage the threads, touch the nut flats instead.
Dan

 

This is all very good information, I hope this is helping others as well.