Tony

87s4 auto
I was told at Sharktoberfest that taking the large yellow wire (pin14) on the 14pin connector and jumping/connecting it to the jump start terminal (12v) nearby should engage the starter and "bypass" all other protection circuitry.(ignition key...tranny switch etc etc)

To verfify...Is this correct?


I have a good 12.5 volts from the jumper post terminal to a nearby ground....however...from the same post to the yellow wire (pin 14) i have nothing. This tells me that the starter isnt grounded, correct? I should have 12v across it if this PIN bypasses everything and goes directly to the starter.

no doubt

Voltage is 12.5 volts on your yellow wire...just measure it to your closest ground to confirm.

Alan

Yes you can do this - though its a high current circuit so be prepared for a good sized spark as you connect and disconnect...
No - the yellow solenoid activation wire is powered only when the starter relay is engaged

Tony - if you don't see voltage between the yellow wire & the jump post - seems the yellow wire may be broken in the loom? With the engine loom connector unplugged (as shown) you can check for ohms between there and the starter small terminal - obviously should be vitually nothing.... Of course if this checks out OK it means the starter solenoid is toast.

Alan

Tony

I dont have 12v on the yellow wire..with the key off...or it on. I get 12 volts from the terminal to a nearby GND key on or off. Somehting is a muck. Time to try a differnt starter.
This would rulle out a relay..fuse...or protection circuit i assume

no doubt

No, his measurement of 0 volts between the hot post and yellow wire means that there is no difference in voltage between them. So if his hot post is 12.5v, then so is his yellow wire.

Presuming that he is accurately describing what and where he measured.

He also describes measuring 12.5 volts between his hot post and ground. If his yellow wire was grounded, then he'd get 12.5 volts difference between his hot post and yellow wire.

If his yellow wire is also 12.5 volts, then he'll get 0 volts difference when measuring between hot post and yellow wire.

Basic electronics.

Tony

OK..im offcially STUPID!
I have found MY mistake....turn the key..the starter barely turned and the car started and sprang to life immediatley...noisey liftres and all. HELL YA!!

More on my mistake later but the simple story is...there are two possible locations to attach the yellow wire on the starter solinoid....I had the wrong one...for reason i'll explain in a bit!

Carl..i nominated myself as the recipient of this years prestigous "Golden Canard Award"


Its starts...it runs!!

no doubt

So what voltages do you measure now that you've corrected the yellow wire connection/placement?

Alan

Hardly... whilst its possible there was 12v on the yellow wire - given the circuit configuration its more likely there was in fact 'nothing' and the yellow circuit was completely open circuit - in which case the DMM would also read 0v. You seem to imply there are only 2 possible states here...

The only conclusive measurement would be measuring the yellow wire directly to ground...

Tony later says it was in fact 0v.. (starter key on/off) If that was with it disconnected as depicted thats possible with an open circuit at the starter.

If the starter were connected correctly (it wasn't apparently) then 12v on the solenoid connector would lead to continual cranking which is the initial reason this didn't seem likely.

Alan

no doubt

That's what I said in my single sentence in post #2.

Alan

You indeed suggested he measure it directly...

I actually initially though you just mean the yellow wire was normally at 12v - that was what I was correcting.

It was apparent that your statement related to the readings Tony gave only with your subsequent post. However you did deduce something not conclusive from the data presented at that point...

We can all be pedantic - that wasn't my point.

I always try to correct statements I see that are technically wrong - for the simple reason that others in the future will read these threads and will assume data presented is correct - we all owe it to them to make sure it is as correct as we can - even small errors can cause people confusion, time wasted, expense and may even lead to damage.

Alan

no doubt

Good point.

Fabio421

Is there no parking pawl in the 928 box?