87 911 bad ignition switch/Neutral safety?

[mkc1962]

Car has been cranking and running great since I bought it a few months ago. Today, wife and I went for a day long road trip and all day everything was great. Stopped for dinner and when we came out, went to crank and nothing. Power was there as everything else came on, but engine would not turn over, no clicking or anything out of starter. Luckily some relatives lived near buy, and we finally got some help.We were was able to push it off, and from there it ran fine all the way home. At first I was thinking the possibility of a neutral safety switch gone bad, but after reading a few threads here, I am lead to believe that these cars don't have one. Another thing I Noticed on the way home was that the heater fans would not operate until after I hit a bump in the road after about 30 Min's of driving.Up until this episode Ive never had any problem out of them either. When this happened I got to thinking ignition switch? When we finally got home and I turned it off, once again nothing. Is it common for ignition switches to just all of a sudden go on these cars? Obviously tomorrow will begin with a multi meter in hand.

[wdfifteen]

I know this won't be much help, but... You situation sounds very familiar. My car will not restart if you sit in the car and turn the ignition off. If you shut it off, then try to start it - nothing. Open the driver's door and close it and the car will start normally. That's all you have to do - open and close the door. I have NO idea why this it.

[mkc1962]

wdfifteen,

beleive it or nor for whatever reason I did try doing that with both doors. I tried everything I could to get a possible loose wire/contact situation, if that were the case, to connect long enough for it to crank. Though Ive done tons of stuff on the car, removing the ignition switch I had not done yet, and did not feel comfortable attempting at 9 at night when it was 22 deg. With all that happened I plan to start my search there after breakfast.

[kidrock]

I'm putting money on the "cold weather gremlin" issue. I've had many older vehicles in the past, and all of them have had similar weird electrical issues when the weather dropped below a certain temperature. I bet that the issue will magically disappear when the weather gets above 40-45 again.

Also...with these cars, grounding issues and dirty contacts can't be ignored. Check and clean the appropriate grounds in this particular system. If that doesn't solve it, you will need to check and clean your power cable to your starter motor. Last but not least, the ignition switch itself is known to have the contacts become oxidized or corroded and should be inspected and cleaned.

EDIT: don't forget the tranny to ground strap.

[mpetry]

+1 on kid rock. My SC seemed to start fine but as winter got colder, I had a couple of "no starts". Remember that in cold weather the battery has lower voltage, but that's not really the problem. The starter solenoid is tired, probably the grease is congealed, poor contacts, etc.

The fix ? Do the easy stuff first. Clean, wire brush, and lube all the connections on the starter, and the same with your ground straps. But the real fix is to buy the "High Torque" starter, which is sold by Pelican for about $250. It is AWESOME and will definitely fix the problem.

[mkc1962]

thanks for the input guys...and you do have some valid points, of which IVe checked near all of them
For now its back to cranking again, but I'm not really sure Ive found the problem.

This morning started by testing to see if the yellow solenoid wire, on the starter was getting full voltage. It was only getting 11.2v regardles whether disconnected or connected to starter. Battery was at a fully charged 12.6. I removed the yellow wire and used a jumper to go from the battery terminal on the starter to the sol and she cranked right up. Starter does not appear to be the problem as it turns over great when it gets full voltage. Sure solenoids go bad, and if this were the original starter, I might tend to wonder about stiff grease and bad contacts. But this is not the original starter. How old I dont have a clue, But it clearly says Bosch Reman on the side. As for all the connections, and ground points. When I had the engine out recently I cleaned all engine electrical connectors including grounds and used dielectric grease on all when reconnecting

From there I went to back of ignition switch and was getting 12.6 in on the red wires, but only the 11.2 on the yellow coming out. I was thinking this might be due to some corrosion on inside of the switch, but before removing the switch I unplugged the connector going through the firewall where it comes right out of the back of the switch and tested the yellow with no load. When I did this I was able to get the switch to keep the 12.6 constant. I hooked this firewall connector back up, and once again only the 11.2. I then tried to apply a full 12.6 to the yellow wire but all I kept getting was a relay clicking somewhere under the hood. Starter was still not getting the 12.6, even if not connected to the solenoid. Clearly the Solenid was not casuing this voltage drop/load.. It appeared as though something was pulling enough of a load to drag the 12.6 down to a point it was not sufficient for the starter. I was under the impression that the yellow wire from the switch goes straight to the starter. According to my Bentley manual, On pre 86 it does, but on 86-89 that yellow wire also goes to a relay that is for the ac system, this relay is found under the hinged lid in the front trunk area. However, in the process of trying to find this relay by constantly applying the 12.6 to the yellow wire the darn thing started cranking fine. When I tested behind the switch again, now I was getting full 12.6 volts going and and out, as well as full 12.6 at starter. Was this relay somehow going bad and causing that voltage drop? I dunno, i cant get it to repeat the problem right now.

For now I do know I can crank it by applying a full 12.6 to the starter IF it does it again. For now I have a jumper apllied to my starter solenoid going up to the engine bay, and a full 12.6 volt wire source as well. If it does it again, I Plan to remove that AC relay and see if the problem goes away. If it does not, atleast I can bump the starter from the engine bay and get it home.

I hate electrical gremlins!!