starter solenoid acting weird

[Dakota Boy]

So when I turn the key, the solenoid goes "clunk", but the starter does nothing. When I "jump" across the solenoid with jumper cables; the car fires right up.

I assumed the solenoid was bad. Went to AdvanceAuto and got another one. Same thing is happening with the new one.

I had my wife turn the key several times while I used a multimeter to measure the voltage on the starter side of the solenoid. I got all sorts of random readings; 6v, 12v once, several times I got zero volts on the meter.

???

[simplyconnected]

You have a loose connection.
It could be dirty battery terminals, a bad wire going to the solenoid, bad ground. etc.

You ran one test across the solenoid with jumper cables. Why did you stop there? Put the jumper cable on your battery post, then go to the starter solenoid (first one side, then the other).

Your meter doesn't lie when it shows resistance. Another "test" I use is to keep the headlights on and watch the voltage drop as the lights dim and the starter motor cranks. Nothing here is technical and it can all be proved with jumper cables.

A dead battery cell will normally show up with the headlight test. - Dave

[jopizz]

Are you sure you have a good ground strap from the motor to the firewall. Most problems I have had with solenoids are due to bad grounds either from the battery to the motor or from the motor to the body. Solenoids are very simple. 12V is sent from the ignition switch to the neutral switch which is then sent to the solenoid. Once energized current flows from the battery side to the starter side. There's not much that can go wrong. Of course you could have gotten a bad one from the store. With the foreign junk that's being made nowadays that's a distinct possibility.

John

[Dakota Boy]

I'll check my ground at the block to the firewall tomorrow. This problem started slowly a few weeks ago, and is getting worse it seems.

Dumb question now; does the solenoid itself require a good ground also? The mounting bracket is metal...

[jopizz]

I'll check my ground at the block to the firewall tomorrow. This problem started slowly a few weeks ago, and is getting worse it seems.

Dumb question now; does the solenoid itself require a good ground also? The mounting bracket is metal...

Yes, the solenoid needs to be securely bolted to the inner fender. That's how it's grounded. That's why it's important to have a good ground from the motor to the body.

John

[Tbird1044]

Greg:
It sounds like when you jumpered around the solenoid and put 12V directly to the cable going to the starter, everything was okay.
First thought is get a new solenoid which you did. Solenoids are nothing more than an electrical coil creating a magnetic field to pull a metal plunger down that connects two contacts. This puts 12V directly across the solenoid going to the starter.
Since you replaced the solenoid and am still having the problem, I would suspect to much resistance in the circuit going to the "S" terminal on the solenoid. It also sounds like you did voltage checks on the S terminal and they were either low or non existent.
If the coil in the solenoid is NOT getting enough voltage to pull down the plunger, the contact will not be sufficient enough to provide the starter with full voltage.
The next test would be to run a heavy jumper from the positive battery terminal to the S terminal on the starter. If it cranks okay, you have to chase the resistance problem back to the ignition switch. Remember that this circuit comes off the ignition switch, through the safety neutral switch, and then to the solenoid. You should be getting close to 12V at the solenoid.
Nyles

[Dakota Boy]

Now we are getting closer I think, Nyles.

The solenoid clunks really loud when this problem is happening. Maybe this noise is from the plunger snapping back to "open" position?

Also, the engine builder installed a different starter that I think has its own solenoid.
There is a wire running from it up to the S terminal.
I need to get the part number off of it, and find the manufacturer's installation instructions as well.

And judging by the wear on the key, my ignition switch is from 1958.

[DKheld]

I know your car is slightly modified but maybe the Neutral Safety Switch (and combined reverse light switch) under the steering column is still used. You could try shifting to Neutral and see if it starts. If so the NSS switch may just need adjusting. That switch has a slotted hole on both ends to slide it around and adjust the contacts. Mine is a real pain in the buttox to get it just right for the car to start while in park and still operate the reverse lights consistently. At the moment it's set so that I have to hold the shifter up a bit for the car to start (or shift to Neutral) ....but at least the reverse lights work consistently . I just call that my theft deterrent system.

I still have the original keys and starter switch too and - knock on wood - they work fine.

The wiring diagram I have is not clear on whether the Red wire with Blue tracer or Red wire with Blue end is coming from the starter solenoid but you can look at the color on the solenoid and figure it out. The other side goes to the S position on the starter switch.


Neutral Safety Switch (pay no attention to the rubber seal for the column - it shouldn't be that close to the switch - I was working on something else at the time and had it slid back)



Eric

[Dakota Boy]

My neutral safety switch is found at the shifter now. (Hurst V-matic II).

I'll have to trace some wires this evening and see what I can find.

I did notice the key turned past its normal "stop" yesterday. That seemed a bit odd as well.

[Dakota Boy]

Update;

I took the ignition switch out of the instrument panel this evening, leaving the wires attached.

I have 12V coming from the battery.
I have 12V going to the accessories.
I have 10V at the pole that sends power to the neutral switch and forward to the starter solenoid.

I have a new ignition switch coming from Birds Nest in another day or two.

[Tbird1044]

From one of your previous posts, it sounds like you have 2 solenoids on your car. The original on the fender and the solenoid on the new starter itself. If your new starter has a solenoid attached, I would get rid of the fender mounted one and run all the wires direct. Every connection will add resistance into the circuit. The critical voltage is what you are getting at the "S" terminal on the original solenoid. Did you try and put 12V directly to this terminal from the battery and see if it cranks over?
Let us know what happens when you install the new ign. switch.
Nyles

[Dakota Boy]

Now that I think about it, I'm pretty sure the previous starter that came with the car also had a solenoid on it.

Thanks Nyles

We'll see what happens in a couple days.

[simplyconnected]

Now that I think about it, I'm pretty sure the previous starter that came with the car also had a solenoid on it...

Now Greg, I realize you're from Wisconsin but, why are you running more than one starter solenoid? When we sent these engines over to you from Detroit, they only had ONE, because that's all you need! Now, you're buying more...

If your starter motor came with a solenoid, use that one and bypass the fender apron switch. - Dave

[Dakota Boy]

I'm fixin' to do just that....

I'm no electrical guru, and the car came already set up like that. I try not to fix what's not broke.... but right now something is broke and it seems to be my ignition switch.

I've been thinking about it, and I cant see a reason for the fender solenoid either.

[simplyconnected]

Just kidding about the "Wisc" part. My brother lives in Brookfield, WI.

I would love to see a picture of your starter, or give me a model number. I am an electrician and I can show you how it should be connected. More importantly, I can show where all the other wires go, as they made the change.

Non-electrical type people tend to change as little as possible, and I understand. Wiring that works doesn't mean it is right or safe.

I am in the middle of a job at a high school buddy's house. He had a stroke but he has also recovered quite well (considering). His house is simple and very old, on a very busy street. Two fuses feed his entire house and of course, both of them are 30-amp. He has a dead short somewhere and I have it narrowed down to two receptacles. I would have fixed it but last time I was there it simply got too late.

"Two 30-amp fuses"...
He said, "Well it worked all these years."
I said, "Yeah, but you just turned the wires in your walls into the real fuses. That's why you have a dead short."

Some say you cannot argue with success but I beg to differ. Just because things work doesn't mean they are safe. That is part of the reason why I ask, 'what do modern cars use?' Hot rodders are famous for making things work but the engineers at the big companies must make sure their cars are safe. Yes there are failures but there are also recalls and law suits. The bottom line is, we want your car to be safe with the hope you come back and buy another. - Dave