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993 starter motor problem.

Sorry can`t help with that.

Other than to suggest with the thin wire at the slenoid disconnected that will stop the starter from trying to start the engine, then if you can have someone look /feel around the relays at the instant you operate the key into the start position, they should feel/hear a click from a relay.

Worth a try..?

Whether there might be an additional imobiliser relay or if R61 performs that function also..I have no idea.

In general and not in the case of your 993... there is no need for a relay if the starter switch can carry the current required by the solenoid as they did in times past.

In auto box cars an aditional switch would be built into the gear selector lever, to inhibit starting unless the selector was in park..

Adding relays allowed the addition of key fob control for security and reduction in the gague of wiring...
 
Re: 993

stichill99 said:
The only other thing that I am puzzled about is that the Bentley manual says that there is supposed to be a starter relay R61 in the bacl left of the fuse/relay box and no such relay is in that position. Obviously it must have one but I don't know where?

I think this is only for cars with the factory immobiliser like my originally German 993. UK cars won't have this as they were delivered as non-immobiliser cars and Hamilton Palmer immobilisers were retro fitted by the dealer..

Factory immobilisers isolate 3 separate circuits (starter, spark and fuel from memory) till the fob button is pressed. R61 is the starter isolator so the car won't crank when immobilised.
 
Gwsinc, thanks for sharing your thinking on the R61 relay.. :thumb:

I suspect IF there may be no relay then the next step might be to check the wiring colours leaving the ign switch and if the same colours are found on the light gague wire at the solenoid, then it seems likely the ign switch directly controls the solenoid on the 993 in question :?:
 
I had exactly the same issue earlier this year. Car in garage on C-tec charger, good battery. Just got a clicking sound.
The car went to my 993 guru and he diagnosed the following which I've copied from his invoice:
"Investigate non starting, trace fault to failed crank reference sensor, remove sensor bracket and cut failed sensor from bracket , renew and set air gap"
 
Ok here you go, the infamous R61, start relay for automatic. My car is not a UK version but a LHD made for the US/ME and Tiptronic S.

ATB :)
 

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hopeydaze said:
I had exactly the same issue earlier this year. Car in garage on C-tec charger, good battery. Just got a clicking sound.
The car went to my 993 guru and he diagnosed the following which I've copied from his invoice:
"Investigate non starting, trace fault to failed crank reference sensor, remove sensor bracket and cut failed sensor from bracket , renew and set air gap"

How did you get it to the guru? When mine just clicked it had to be trailered. No cranking at all. My 'guru' dismissed sensors on the basis that it wasn't turning over.
 
My guess is that there may be quite a few Guru`s out there who will differ in their way of working...

Complexity seems to creep in wherever digital controls are involved in circuitry. and in the case of some 993`s it seems that a simple starter motor control circuit may be complicated by the introduction of inhibitor circuitry which involves key fob activation to overcome the initial barrier to start-up. Quite what part a crank rotation sensor might have at that early stage of the cranking process I have no idea but would not totally discount it.

My guess would be that a crank speed rotation sensor input could be used for many aspects of the control system, and as part of the start up process it could be used to maintain a supply to the relay controlling the fuel pump (R61?) via the ECU in case of an accident where the ign may still be on and a fuel line ruptured, the idea then being to stop the pump supplying fuel to the crash site, as the ECU would loose the signal from the crank sensor as the engine had stopped rotating..!

If the above may be the case, then I can imagine the case where hopeydaze could initially turn the engine over but it would not star, t as the fuel pump may not run without the ECU seeing the input from the crank speed sensor... But it seems that was not the case for hopedaze as all he reports was just a click when he turned the ign key...?

Given the many options available in the programming of digital electronics... I give in... as old fashioned non-guru electro/mechanical thinking has long since been surpassed.. :dont know:
 
Les Richards said:
hopeydaze said:
I had exactly the same issue earlier this year. Car in garage on C-tec charger, good battery. Just got a clicking sound.
The car went to my 993 guru and he diagnosed the following which I've copied from his invoice:
"Investigate non starting, trace fault to failed crank reference sensor, remove sensor bracket and cut failed sensor from bracket , renew and set air gap"

How did you get it to the guru? When mine just clicked it had to be trailered. No cranking at all. My 'guru' dismissed sensors on the basis that it wasn't turning over.
Simple. I'm insured with Classicline and that includes breakdown cover. First time I've had to call on them and the process was very efficient They sent a breakdown truck,winched it onto the flatbed and took it from my house in Bath 20 miles to Devizes
 

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