Weird starter problem. After starting, key to ON, starter keeps spinning. [Archive] - SaabCentral Forums

: Weird starter problem. After starting, key to ON, starter keeps spinning.


jonboy545
1st October 2005, 05:02 PM
Hey guys.

About a week ago my starter went out.

Just got one in, and replaced it today.

Get the new starter in, goto start my car, and after its 'started' the motor keeps turning.

I'm pretty sure all the wires are in correctly, so it's either that, a solenoid problem, or the ignition switch... I think :( I have no voltmeter so I dont really have a way of testing.

Now the two smaller gauge wires (two positives) are for the bendix solenoid and the motor correct? The two larger gauge wires (small wires) are for what? That I don't know.

Has anyone ever heard of this problem? Did I simply get two of the wires mixed? Anyone have a picture of the wires and where they go? I still have not bought a bently manual. Plan on doing that next paycheck.

Any help is greatly appreciated,
Jonathan

jonboy545
1st October 2005, 05:03 PM
I can't tell if the solenoid that moves the gear over the flywheel is still engaged after the car is running or not. Too much noise.

Rich3Saabs
1st October 2005, 05:13 PM
The Starter motor can keep running because of a number of things. It receives its power from the large contacts (switch) in the starter solenoid. WHen engaged, this starter sol. allows high current 12 volts to run the starter motor.
A number of things can cause the starter solenoid to stay engaged:
A) stuck starter solenoid mechanicals. probably not the cause
B) more likely a defective start position on the ignition switch in the ignition switch
C) possibly a gummed up ignition key tumbler
I would start troubleshooting with a schematic. Make your own or purchase a service manual. IF you pull off the wire from the switch (in the center console) which actuates the starter solenoid, and the starter motor continues to run, then its not the switch or the key tumbler. its the solenoid.
Troubleshooting is the logical process of elimination. Good luck:D

ProfZ
5th October 2005, 01:40 AM
Jon, you need to tell us what year/model your car is, and whether it's an 8- or 16-valve engine:confused:

jonboy545
7th October 2005, 04:46 PM
Whoops...

Well, thought the electronics would all be the same anyhow.

It's an 87 8 valve.


I think what I'm going to do is just take the key cylinder apart, and make a push button starter. One switch for fuelpump/ignition/ECU. My car is a POS. No carpet, bad paint, no passenger seat! Nobody is gonna steal it. If they can figure out how to shift the damn thing, hey... let'em have it! I got it for free anyhow.

jonboy545
30th October 2005, 07:56 PM
For reference.... this is the problem:

87 900 8V
http://www.saabcentral.com/forums/showthread.php?t=59853


I thought the problem was with the ignition switch.

Instead of installing a push button starter, I simply put a switch in between the the large wire for the actual starter relay. All the other ignition wires are normal, except the large gauge wire for the starter relay (wire "50").
So basicly when I turn the switch off, the only thing that doesn't work is the starter. When the switch is on, it works "as normal."

Well, that wasn't the problem.

Here's what makes this problem even stranger.

About 2-3 out of every 10 starts, the starter does in fact turn off, but the alternator/battery light comes on and the alternator is only putting out 12V, not 14.5 as normal.

I couldn't find a relay labled "starter relay" and without any documentation, I guessed "Ignition Lock" relaw was the starter relay.

When I pull this relay, the starter stops spinning every time. Note this is only once the car begins running. When the key is turned off and the engine is off, the starter does turn off. Not showing signs of a short circuit somewhere (that I know of.)

Also, when I do pull the ignition lock relay, the tachometer stops working (I guess as usual) and the alternator does not charge any times.

I put the relay back in while the car is running, nothing changes.

Turn the car off, put the relay back in... start the car. No alternator light comes on, however the starter is still spinning. I can not tell if the bendix solenoid is engaged to the flywheel as well, but I do not think so. Starter doesn't make any kind of different sounds when the engine is revved.

So the alternator light and starter spinning are directly related somehow. Light on: no starter problem. Light off: starter keeps spinning after engine running.


So is it possible that I reversed the two large positive wires that goto the starter? The large wire directly coming off the battery terminal is connected to the post closest to the driver's side. The large positive wire coming off the alternator is going to the post closest to the middle of the car. Are there only two large red wires going to the starter? One from alternator, one from battery terminal?

I really need to get this issue resolved as I cannot drive my car with the starter spinning, this is a brand new starter. If you need anything clarified please ask so. I'm completely stumped.

Thank you very much,
Jonathan

ProfZ
30th October 2005, 09:53 PM
So is it possible that I reversed the two large positive wires that goto the starter? The large wire directly coming off the battery terminal is connected to the post closest to the driver's side. The large positive wire coming off the alternator is going to the post closest to the middle of the car. Are there only two large red wires going to the starter? One from alternator, one from battery terminal?


Jon, you've almost nailed your problem:)

Both of the red cables (one from batt +, one from alt) are supposed to go on the outer terminal on your solenoid.

jonboy545
1st November 2005, 04:23 AM
Hmm, then what goes on the inner terminal? A ground?

I coudln't find another wire anywhere under there, but I'm probably mistaken.

THANK YOU!!!
Jon

cdaly
1st November 2005, 05:13 AM
So the alternator light and starter spinning are directly related somehow. Light on: no starter problem. Light off: starter keeps spinning after engine running.
So is it possible that I reversed the two large positive wires that goto the starter? The large wire directly coming off the battery terminal is connected to the post closest to the driver's side. The large positive wire coming off the alternator is going to the post closest to the middle of the car. Are there only two large red wires going to the starter? One from alternator, one from battery terminal?
Jon, you've almost nailed your problem:)

Both of the red cables (one from batt +, one from alt) are supposed to go on the outer terminal on your solenoid.
The relationship is that the large positive wire off the alternator is connected to the motor side of the starter solenoid instead of to the battery side. When the alternator starts charging, it starts supplying current to the starter motor which then spins (and not to the battery so that should be running down). When the alternator fails to start charging, there's no current supplied to the starter.

There should be no external cables connected to the terminal you mentioned, both should be connected to the outer terminal. The starter doesn't need a separate ground cable, it grounds through the engine block and the main battery to engine block ground wire.

Now, once you've connected the starter correctly, you're going to need to check that your alternator is working correctly. If I'm not mistaken (which is possible, however unlikely that may seem :D ), the alternator has been running at full output while trying to spin the starter. That may not be an issue for it but the 3 out of 10 starts where the battery light stays on could suggest a problem. OTOH, it may be that the battery has been running down causing the alternator not to charge at times and it could all be fine once things are correctly connected.

If you don't have a voltmeter, either buy a cheap (digital) one for $15 or stop by a local mechanic and ask to use theirs. Do the following tests:


With engine off:

check battery voltage (should be about 12.5V)
Check voltage at alternator heavy terminal (should be close to battery voltage)
Check voltage at alternator excitation terminal (small spade connector near main terminal) (should be zero)

Switch on ignition:

Check voltage at excitation terminal (should be near but less than battery voltage)

Start engine:

Check battery voltage (should be at least 13.5V and rising)
Check voltage at alternator main terminal (should be greater than battery voltage but not by much)
Check voltage at alternator excitation terminal (should be same as main terminal)
Check battery light is out
Rev engine to 2500 rpm and check battery voltage (should be near 14V)
Rev engine to 4500 rpm and check battery voltage (should still be near 14V)
Switch on high beam headlamps, rear screen demister, windscreen wipers, rev engine to 2500 rpm and check battery voltage (should be 13.5V - 14V)

If all of these check out, you alternator's probably fine. If they don't check out, record the numbers and post them here and we'll see what we can do...

Rich3Saabs
1st November 2005, 12:01 PM
It was posted that: "When the alternator starts charging, it starts supplying current to the starter motor which then spins (and not to the battery so that should be running down). When the alternator fails to start charging, there's no current supplied to the starter."
This is incorrect. The starter motor which requires upwards of perhaps 300AMPS to operate will not and can not get this much current from an 80 AMP rated alternator.
One can remove the alternator from the car and you will still be able to crank the car over. It may even start since the battery, if it has sufficient charge, will operate the car for quite a time.
Additionally, the alternator will not produce the amount of voltage required to be useful at slow cranking rpms.
Hope this helps.

cdaly
1st November 2005, 01:38 PM
That's fair enough when normally connected. However, in this case, the alternator charging wire was incorrectly connected to the starter motor side of the solenoid. When the alternator starts charging, it will supply voltage to the motor windings. The solenoid will not engage and so the bendix will not engage the flywheel. In this state the starter motor will not require the 300A starting current and will happily turn over at a reasonable speed on fairly low current, certainly the 80A that the alternator can supply will be sufficient.

Your assertion that the alternator cannot supply enough power to enable the starter motor to turn over the engine is correct but, under these circumstances, there would be sufficient power to turn the starter alone.

Note that the 300A that a starter motor can draw happens only while it is stationary. Once turning, the motor generates a 'back emf' which opposes the flow of current through the motor. As the motor speeds up, the back emf increases, increasing the 'resistance' of the motor and thus reducing the current the motor will draw. A heavy load will slow a motor down, reducing the back emf, allowing more current to flow, speeding up the motor. This means that, up to a limit, an electric motor will run at a constant speed regardless of load. When the load increases beyond the motor's ability, the motor will burn out {unless there is suitable over current protection}.

jonboy545
1st November 2005, 08:33 PM
Thank you very much guys, that solved the problem 100 percent.

All alternator voltages checked out, and I also took it to my local Advance Auto to ensure that the amperage checked out as well.

Everything is A#1- OK!!!!!


That was exactly the problem!!!

So whoever said the 80A from the alternator won't spin the starter was wrong, as it sure as hell did! :)
As said before, the bendix solenoid was not engaged, but it did spin, and quite fast too...

Car drives good as new after a good deep trickle charge to the battery today, and I will HAPPILY be driving it to work tomorrow morning! It's a good thing that I did install the starter "cut out switch" since the key is still sticking in the start position sometimes. This must be how the starter burned out the first time. I just put the wires on the wrong way :lol:

Now I just need to start saving for a clutch kit, and figure out if I have the guts to try it.

Thank you again for the 911 rescue, I'm so glad I could get this solved.

Jon

Rich3Saabs
2nd November 2005, 09:20 AM
I believe you are misassociating functions. Battery turns the starter, The Alternator's sole function is to charge the battery while running electrical loads.
What turns the starter before the alternator comes up to speed?
Check the Bentley or any other automotive book to confirm above.
Anyway, I am glad you got the car started and it is running fine.

I just had a situation with a 1995 Saturn SW-2. Alternator totally dead.
I put in a charged battery and started the car and drove it home.
The fact is, the car will start and run with a dead alternator.
PM me for more details if necessary. Good luck!

cdaly
2nd November 2005, 10:10 AM
I believe you are misassociating functions. Battery turns the starter, The Alternator's sole function is to charge the battery while running electrical loads.
In the normal course yes. However, in this case, the OP had connected the alternator -> battery cable to the wrong connection on the starter motor so that it was no longer charging the battery as it should but was instead trying to turn the starter.

Rich3Saabs
2nd November 2005, 12:54 PM
I see what my disconnect was. The circuit was not wired as intended.
It looked like a case of Starter turns Alternator, alternator turns starter, starter turns alternator. on and on which we all know would be perpetual motion. I thing the engine usually is on its own before the alternator could supply any watts to the total system...most of it going to a partially discharged battery post start.
I am glad he got his car figured out and just wanted to help by explaining the intent of the circuits and components in a normal system.

jonboy545
3rd November 2005, 03:04 PM
Thanks guys...

Yeah, I understand completely how the charging/starting system works...

I've ran cars for days and days with bad alternators... after the car is started, the only thing sucking off the battery is the fuel pump, ECU, and ignition. Of those, the fuel pump is using the most amperage. Of course accessories and lights and such too, but for basic engine running, that's all its sucking from it. I've also ran my Saab for over a month with a bad battery, by "bump starting it" pushing or rolling the car and dumping the clutch in 2nd gear. This spins the alternator at at least 600+ RPM, thus giving enough amperage to power the said systems above (fuel pump, ignition, ECU, and even the headlights worked fine)

It was just a fact of seeing TWO terminals, and not thinking that one should not be used.

Thanks again guys, car is driving solid as a rock! Can't believe it was something so simple... though it USUALLY is something very simple right in front of your eyes ;)