996 Cab will not start or turn over

[Serg]

1999 Porsche 996 Cabriolet automatic.

 

Wife drove car to market and when came out tried to start; she turned it over a couple of time with no engagement of start or sound, then it started right up.

 

When I got home same day I attempted to turn car over; two unsuccessful tries then it start normally.  I tried again and nothing since.

 

When turning key, there is no hesitation in key movement and no play.

All dash lights come on EXCEPT the check engine light.

 

I just replaced battery 3 weeks prior and have had it checked

I had starter bench tested and it works fine

I replaced the "RF" signal trans/receiver at the rear of the ignition switch

I have check all fuses in primary and secondary; replaced the starter relay

 

The immobilizer has never been wet and the fuse is operational

 

Symptoms:

 

when key is engaged in start position - there is an "electrical" sounding hum from the starter area

I hear nothing in the secondary relay area - but I could be missing it

The fact that the "check engine" light does not come on makes me uneasy - but I don't know if this is a red flag

when I put key into door lock and lock and unlock I get one beep and the locks works as it should

the red led light blinks as it always has, one flash per second or so

 

 

At wits end on this one.  Any suggestions?  Its scheduled to be towed to nearest deanship Friday (65 mi away)

 

All I can come up with is that the pill is not being read and must be re-flashed...no I don't have a spare.

 

Thank you in advance.

 

 

 

[JFP in PA]

Check your primary battery cables for voltage drop.  These cars came with cables prone to internal corrosion which leads to sudden issue like this.  You should not have a voltage drop of more than 0.5V on any cable; it it is higher the cable has to be replaced.

[Serg]

JFP,

 

While electrical has never been my game, I did visually inspect the Alt/Starter cable when I pulled the starter and there was no corrosion, but I do understand your point about "internal".

 

As to the "ground" cable in the rear passenger wheel well; I did confirm good contact.  If I could impose, could you please identify any specific locations to check and (I know this gives away my level of ignorance) the methodology? 

 

Thank you for taking the time for the original reply.

 

Serg

Edited October 21, 2019 by Serg

[judgejon]

Try pulling cables, cleaning connections, then reconnecting.  Could be a spot of corrosion on battery posts that restricting voltage. Hope you can avoid the tow...

[DBJoe996]

You say you have a new battery.  Why did you put in a new battery?  Was the old one giving you trouble?  What size new battery and how many reserve amps?

It sounds to me to be just like when the starter gets heat soaked and the solenoid doesn't kick it.  Does the starter motor run when you try to start it, and just not engage the bendix gear to the flywheel?

It is okay to check the voltage drop between the battery and the engine bay connection with a multimeter.  However, when you start disconnecting things to check for corrosion or loose connections, always disconnect the negative lead on the battery first.

Usually one of the first culprits in this type of situation is the electrical part of the ignition switch.  You might want to replace it first before doing other things.

Edited October 22, 2019 by DBJoe996

[Serg]

Judgejon: battery posts are clear and clean as well as the cable connections thereto.  Thx

 

DBJoe996: New battery after 4 years and old battery was just used up as indicated by testing; replaced with same battery as previous.  The Starter was not over heated, this was on a relatively cold, the starter was bench tested and operated as it should repeatedly.  When in car and ignition is engage the starter does not crank at all but I do hear the hum of electrical current.  The electrical part of the ignition switch was replaced.  Thx.

 

So to check for corrosion; is the correct procedure to disconnect the neg ground at battery and then check the cable components with multi-meter for a voltage drop by placing a lead on the component and a lead on ground?  At stand no load should the voltage at the battery be roughly 12.7v?  Sorry for my naivete as to electrical issues.

 

 

 

Edited October 22, 2019 by Serg

[DBJoe996]

It sounds to me from your description that the starter motor is spinning but the solenoid is not kicking in the bendix.  Bench testing is one thing.  A starter motor requires a tremendous amount of amperage to operate, thus the two circuits to make it happen.  One is the main lead (big heavy wire main lead) that spins up the starter motor, and then the smaller lead to the solenoid to kick in the bendix.  Are you familiar with the Y-cable?  This is the one that connects to the starter circuit from the main junction point in  the engine bay.  Notorious for failing from internal corrosion.  What is the voltage at the main junction box (+ jumper point) in the engine bay?

[Serg]

DBJoe996:  You may have a point from the more I read and from JFP's original post; it could be that what I am hearing is the solenoid but due to restriction in the current the Bendix does not kick in.  With that said, can you tell me where the main junction box is in the engine bay?  Is this were the Y cable is connected up to the battery.  I found a post, but it was a 997, that identified the location as being the right side of the tranny housing for the connection point of the Y cable, yet from your indication of "engine bay" I suspect a different location on the 996.

[DBJoe996]

Look just to the right of the power steering pump.  There is a black box that has a lid.  Open the lid and there is the main junction for the starter.  Careful, it is live and carries volts like it is connected straight to the battery.

The Y-cable is #21 in this diagram 

Battery Power Distributor Starter Generator

WWW.AUTOATLANTA.COM

---

 

 

[Serg]

DBJoe996: Thank you for your help.  I will take a look this evening.  Hopefully, this is the culprit and I can cancel the trip to the dealership and fix it myself.  If so, next time out west, beer is on me.

[Serg]

Well I tested with a multi meter at the "+" post and at the nut on the starter where the cable that comes from the Alt; there was only a .1v drop from the reading at the battery terminals.  The only thing that I can think of is the pill in the key is not being read.  Have I missed anything?  Thank you every one for your help.   BTW: I did peal back some of the sheath off of the cable at the "+" (where i could) and at the connection at the starter...didn't see any corrosion.  

[Serg]

I thought I would reply to this topic with (what I think is a plausible but highly suspect) resolution:

 

After taking the car to the dealership and explaining what I had done and what I suspected the problem to be, they had the car for 3 days.  On the 3rd day they contacted me to confirm what I originally told them.  That I suspected that the signal between the pill and the ignition was not talking place.  I had provided them a new fob and blade that I had ordered from an outfit in the UK (members here had stated confirmation of the validity of key blades and fobs from them as operational).  I had indicated that I believed that if they placed the "pill" in the new fob with the new blade (which unlocks the car and lights up the dash lights) and re-flashed the pill that that might be what is necessary.  

 

And here is where the suspicious side glance comes in:  The service manager stated to me that they were able to get the car started using the pill in the original fob (it was broken - another story) and using pliers to turn the old blade.  BUT that placing the pill in the new fob head with the new blade would not work.  As such I would need a new fob head and blade from the "Fatherland" to the tune of $550.

 

Though I repeatedly asked if he could explain why the fob head (old and new) would make any different he couldn't; why placing the pill in the original fob and keeping it in the vicinity of the ignition why using the new fob and blade would not work - he couldn't; so now I will wait 4 days for the new key fob and blade from Germany.

 

I don't know, something fishy in Denmark or am I just over reacting?

[JFP in PA]

1 hour ago, Serg said:

I thought I would reply to this topic with (what I think is a plausible but highly suspect) resolution:

 

After taking the car to the dealership and explaining what I had done and what I suspected the problem to be, they had the car for 3 days.  On the 3rd day they contacted me to confirm what I originally told them.  That I suspected that the signal between the pill and the ignition was not talking place.  I had provided them a new fob and blade that I had ordered from an outfit in the UK (members here had stated confirmation of the validity of key blades and fobs from them as operational).  I had indicated that I believed that if they placed the "pill" in the new fob with the new blade (which unlocks the car and lights up the dash lights) and re-flashed the pill that that might be what is necessary.  

 

And here is where the suspicious side glance comes in:  The service manager stated to me that they were able to get the car started using the pill in the original fob (it was broken - another story) and using pliers to turn the old blade.  BUT that placing the pill in the new fob head with the new blade would not work.  As such I would need a new fob head and blade from the "Fatherland" to the tune of $550.

 

Though I repeatedly asked if he could explain why the fob head (old and new) would make any different he couldn't; why placing the pill in the original fob and keeping it in the vicinity of the ignition why using the new fob and blade would not work - he couldn't; so now I will wait 4 days for the new key fob and blade from Germany.

 

I don't know, something fishy in Denmark or am I just over reacting?

 

Questionable...………...

[judgejon]

Like sometimes happens with questionable sellers on Amazon, I’d bet you purchased a cheaply made knock-off of the key fob.  Blade probably not the issue if laser cut looked close to original.  
We had a key go missing once due to a purse theft.  Had to order from stealership that in turn had to order from factory.  Yeah, big bucks.  Good luck...

[Serg]

Well the Key fob/blade came from "keys-in-the-post" which many on here have used and said worked out for them.... so, idk.   Think I will get it fixed, get it back, then write a letter and see what happens.