Dead starter circuit when warm
09-21-2017, 03:04 PM
#1
2nd Gear
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Dead starter circuit when warm
I have a new starter/solenoid, starter relay and battery. The 928 S4 starts fine when cold. After driving a while and shut off, The starter will not run. After the engine is totally cold, the car starts right up without touching the shift lever, or anything else. The ignition switch seems fine. The problem seems to me to be related to heat build-up under the hood. At this point, it seems related to a wiring, or wire connection problem. Suggestions as to where to look next?
I see various suggestions with reference to test points such as 30, 85, 86, 87, and 14, but no description of physically where they are in the car, or how to access them. Is there documentation somewhere that describes this?
I see various suggestions with reference to test points such as 30, 85, 86, 87, and 14, but no description of physically where they are in the car, or how to access them. Is there documentation somewhere that describes this?
09-21-2017, 03:11 PM
#2
Drifting
I had the same problem, and replacing the starter solved it.
Your new starter may be bad.
Your new starter may be bad.
09-21-2017, 03:13 PM
#3
Rennlist Member
Look at the wire at the connectors in the spare tire well - that's where my identical issue was with my 86.5 years ago. Frayed wires.
09-21-2017, 07:42 PM
#4
Nordschleife Master
The numbers 30, 85, 86 & 87 are the connections for the relay.
85 & 86 are the "control" connections (the low power that activates the relay), 30 & 87 are the "controlled" connections (the power that the relay supplies). Some relays have a little diagram on them that shows this (I'm not kidding about "little" - you may need a magnifying glass).
The "14" is the 14 pin connector. It's the main plug for the engine harness. It's on the right fender, just forward of the crossbrace. It's right next to the "hot post".There should be a boxy plastic cover over it, and a cap on the hot post.
There is a yellow wire in the 14 pin. That is the solenoid for the starter. Put 12 volts to it and the starter should crank (presuming you have power to the starter) 14.
Things I would check:
Main power connection at starter.
Cable to starter.
Solenoid power (commonly called the "S-terminal").
If you have power to all of those things when hot, I'd suspect the starter or solenoid.
If you aren't getting a fairly loud "click" when you hit the key, I'd suspect the solenoid.
They can be defective when new.
85 & 86 are the "control" connections (the low power that activates the relay), 30 & 87 are the "controlled" connections (the power that the relay supplies). Some relays have a little diagram on them that shows this (I'm not kidding about "little" - you may need a magnifying glass).
The "14" is the 14 pin connector. It's the main plug for the engine harness. It's on the right fender, just forward of the crossbrace. It's right next to the "hot post".There should be a boxy plastic cover over it, and a cap on the hot post.
There is a yellow wire in the 14 pin. That is the solenoid for the starter. Put 12 volts to it and the starter should crank (presuming you have power to the starter) 14.
Things I would check:
Main power connection at starter.
Cable to starter.
Solenoid power (commonly called the "S-terminal").
If you have power to all of those things when hot, I'd suspect the starter or solenoid.
If you aren't getting a fairly loud "click" when you hit the key, I'd suspect the solenoid.
They can be defective when new.