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996 Carrera won't start. Not getting 12v to starter solenoid. Plea


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Please help! I have a 1999 Porsche 996 C-2 Coupe. It has just over 100,000 miles. When I try to start the car, it does not start. I have tracked back to the starter. I am getting current, but I do not get 12v to the solenoid when I turn the key. I hear the fuel pump prime. All the dash warning lights come on. All electrical work properly, but the starter will not turn and the engine will not fire. I have checked EVERY SINGLE fuse. I even tested with meter for continuity (sometimes a fuse will not look broken even when it is). I also checked and cleaned the ground strap on the passenger side of the engine. All the contacts (engine ground, starter and alternator) look clean and free of corrosion.

Should I look for a starter relay to test? How is this done? What about the clutch pedal switch? Does anyone know how to check or jump the clutch pedal switch? Is there anything I am missing?

Here is the history. Last summer, the car would start VERY VERY slowly once it was warm. As I understand, heat causes resistance, and after you drive the car for some distance, restarting can really stress an old starter or appear from a poor ground strap. 

This winter, I attempted to start the car in the cold. It started fine. Upon restart, it wouldn’t turn over enough to start the car. I had the car started with the aid of jumper cables, and I drove it to Auto Zone. Battery was charged and tested…passed with flying colors. Drove car home. Next day, car started but wouldn’t restart. It was the SAME THING, so we jumped it and I drove it home. 

Next day, I removed and cleaned the ground strap. Retested it….car started but wouldn’t restart 20 minutes later. Then I removed the starter and alternator. Both were bench tested. Both passed all tests. I bought a starter anyway. After install, the car will not turn over AT ALL. I removed the new starter and took it back to Auto Zone to bench test. It engaged and started spinning and passed all tests. Then I put it back in the car and found 12v not going to the solenoid. So I bought a new ignition switch and installed that. I am still not getting any power to the solenoid.

Please help me get this baby running.

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Certainly sounds like a relay, I had a similar "gremlin" with my 94 Surburban, car would start and run then die randomly and crank, but not turn over. Then after sitting for 10 minutes the car would come back to life and be fine, turned out to be the fuel pump relay. I'd definitely try the starter relay first, check your manual to find the corresponding location.

 

As far as the clutch switch goes; In my car, 2001, I hear an actual "click" when I put the clutch to the floor to engage the clutch microswitch before I start the car. 

 

http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/93-ELEC-Brake-Clutch_and_Cruise_Control_Switch_Replacement/93-ELEC-Brake-Clutch_and_Cruise_Control_Switch_Replacement.htm

 

There's a link from pelican parts on the microswitches

 

Keep us posted.

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I had a similar problem on a different vehicle some years back.  It would start OK when cold, but when hot it would not always turn the starter.  Not even the click of the starter solenoid.  I had the starter motor checked and it was OK.

 

I finally tracked this problem to the low current wire to the starter solenoid.  At its end it had a female spade connector.  When it was getting hot from engine heat it was expanding and losing its clench on the male spade on the starter solenoid housing.  As a result it was not transmitting a voltage to the starter solenoid when the starter switch was activated.

 

I think I would now try and find out if the low current wire to the solenoid is properly connected and ensure that it is not broken within the insulation and that it has a good solid connection to the solenoid post.  You might even consider replacing the last foot or so of wire.

 

 

H  

Edited by Hilux2400
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  • 3 weeks later...

Has this been resolved?

 

I am having a similar issue with my 1999 996.  Starter relay clicks but no start.  (I tested the relay with 9v battery - it energizes.)  I disassembled the component to get to the starter and tested - not getting 12v to starter when the key is turned.

 

Any info appreciated.

 

Thanks,

-Don

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Has this been resolved?

 

I am having a similar issue with my 1999 996.  Starter relay clicks but no start.  (I tested the relay with 9v battery - it energizes.)  I disassembled the component to get to the starter and tested - not getting 12v to starter when the key is turned.

 

Any info appreciated.

 

Thanks,

-Don

 

Power flow : battery-> ignition switch -> relay -> starter solenoid. You have a break somewhere along the line.

 

Try this. Remove the relay and see if you get 12v on pin 30 on the relay socket when you turn the key to crank. If you don't, it's likely your ignition switch is bad. If you do get 12v, it's likely your relay is bad. To verify, check continuity between pin 30 and 87 of the relay. They should close when the relay is energized. If that checks out, you may have a wiring issue between the relay and the starter solenoid (much less likely). If the relay is bad, you can temporarily put a short and fat jumper (awg16 or thicker) between pin 30 and 87 of the relay socket to start the car. A thin jumper will not work as the solenoid needs 30~40A to operate.

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Has this been resolved?

 

I am having a similar issue with my 1999 996.  Starter relay clicks but no start.  (I tested the relay with 9v battery - it energizes.)  I disassembled the component to get to the starter and tested - not getting 12v to starter when the key is turned.

 

Any info appreciated.

 

Thanks,

-Don

 

Power flow : battery-> ignition switch -> relay -> starter solenoid. You have a break somewhere along the line.

 

Try this. Remove the relay and see if you get 12v on pin 30 on the relay socket when you turn the key to crank. If you don't, it's likely your ignition switch is bad. If you do get 12v, it's likely your relay is bad. To verify, check continuity between pin 30 and 87 of the relay. They should close when the relay is energized. If that checks out, you may have a wiring issue between the relay and the starter solenoid (much less likely). If the relay is bad, you can temporarily put a short and fat jumper (awg16 or thicker) between pin 30 and 87 of the relay socket to start the car. A thin jumper will not work as the solenoid needs 30~40A to operate.

 

 

Tested the above.

 

No +12v on pin 30 of the relay socket.

 

Does that make it the starter switch?  What if the battery does not have enough amps?  It was tested at NAPA at 750CCA, but the headlights are dim.

 

I replaced the starter switch only two weeks ago.

 

Thanks,

-Don

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Has this been resolved?

 

I am having a similar issue with my 1999 996.  Starter relay clicks but no start.  (I tested the relay with 9v battery - it energizes.)  I disassembled the component to get to the starter and tested - not getting 12v to starter when the key is turned.

 

Any info appreciated.

 

Thanks,

-Don

 

Power flow : battery-> ignition switch -> relay -> starter solenoid. You have a break somewhere along the line.

 

Try this. Remove the relay and see if you get 12v on pin 30 on the relay socket when you turn the key to crank. If you don't, it's likely your ignition switch is bad. If you do get 12v, it's likely your relay is bad. To verify, check continuity between pin 30 and 87 of the relay. They should close when the relay is energized. If that checks out, you may have a wiring issue between the relay and the starter solenoid (much less likely). If the relay is bad, you can temporarily put a short and fat jumper (awg16 or thicker) between pin 30 and 87 of the relay socket to start the car. A thin jumper will not work as the solenoid needs 30~40A to operate.

 

 

Tested the above.

 

No +12v on pin 30 of the relay socket.

 

Does that make it the starter switch?  What if the battery does not have enough amps?  It was tested at NAPA at 750CCA, but the headlights are dim.

 

I replaced the starter switch only two weeks ago.

 

Thanks,

-Don

 

No 12v on pin 30 when you turn the key to crank, meaning 0v right? If yes, then your ignition switch or the wiring between the ignition switch and pin 30 has a break. The former is much more likely.

 

By starter switch, do you mean ignition switch? If so, it's also the last thing touched...

 

A weak battery may not be able to energize the solenoid but at least you should get some voltage on pin 30.

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Has this been resolved?

 

I am having a similar issue with my 1999 996.  Starter relay clicks but no start.  (I tested the relay with 9v battery - it energizes.)  I disassembled the component to get to the starter and tested - not getting 12v to starter when the key is turned.

 

Any info appreciated.

 

Thanks,

-Don

 

Power flow : battery-> ignition switch -> relay -> starter solenoid. You have a break somewhere along the line.

 

Try this. Remove the relay and see if you get 12v on pin 30 on the relay socket when you turn the key to crank. If you don't, it's likely your ignition switch is bad. If you do get 12v, it's likely your relay is bad. To verify, check continuity between pin 30 and 87 of the relay. They should close when the relay is energized. If that checks out, you may have a wiring issue between the relay and the starter solenoid (much less likely). If the relay is bad, you can temporarily put a short and fat jumper (awg16 or thicker) between pin 30 and 87 of the relay socket to start the car. A thin jumper will not work as the solenoid needs 30~40A to operate.

 

 

Tested the above.

 

No +12v on pin 30 of the relay socket.

 

Does that make it the starter switch?  What if the battery does not have enough amps?  It was tested at NAPA at 750CCA, but the headlights are dim.

 

I replaced the starter switch only two weeks ago.

 

Thanks,

-Don

 

No 12v on pin 30 when you turn the key to crank, meaning 0v right? If yes, then your ignition switch or the wiring between the ignition switch and pin 30 has a break. The former is much more likely.

 

By starter switch, do you mean ignition switch? If so, it's also the last thing touched...

 

A weak battery may not be able to energize the solenoid but at least you should get some voltage on pin 30.

 

Correct - 0v on pin 30.

 

Yes, the ignition switch.  I replaced the switch a week ago Sunday, then took it out for a drive.  Started successfully all day.  Went to start the next morning, turned the key, gauges and dash lights came on but no start.  (Switch was replaced because previous switched was broken when someone at the emissions testing overcranked to try and turn off the car.)

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I would suggest you retrace your work. Could be just the socket not fully seated. Remove the electrical connector to the ignition switch and find the solid yellow wire on the connector. That wire connects directly to pin 30. Check continuity between the connector and pin 30. If there's continuity, it's almost certain your switch is bad.

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I would suggest you retrace your work. Could be just the socket not fully seated. Remove the electrical connector to the ignition switch and find the solid yellow wire on the connector. That wire connects directly to pin 30. Check continuity between the connector and pin 30. If there's continuity, it's almost certain your switch is bad.

Thanks for the further information.  I will try and get in to check that tonight.

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This starts to sound like you have a faulty battery. When it won't start - try to jump start it.

That may be true too but I doubt that's the root cause as the OP mentioned when he turned the key, all the electrical things work and he could hear the fuel pump. That indicates the battery at least have some power/voltage and the ignition switch is getting power from it. It's just not sending power to pin 30 of the starter relay.

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