no start v6

[John Cody Forbes]

>
>> Since most of you seem to think it's the starter (or the starter
>> wiring), I dug out the Bentley for my old 200 (assuming things
>> don't change much in the starter circuits), and put together a
>> Twiki page for the KB.
>>
>> http://www.audifans.com/twiki/bin/view/Audi/NoStartStarter
>>
>> Let me know if I mis-interpreted or mis-read things.
>

You may also add the quick and dirty method to narrow things down very very 
quickly. If your starter does not engage when turning the key simply check 
for decent battery voltage (visually even by noting if the dashboard lights 
are un-usually dim). If you have decent voltage just take a screwdriver or 
other metal object preferably with a rubber hand grip and bridge the "big 
wire" starter terminal to the "small wire" terminal, simply put.

 If nothing happens then 75% chance says the the starter is bad. From here 
other things to check to really pinpoint the starter as the culprit is 
verify at least +10volts constant on the large battery cable to the starter. 
Use the starter body for your ground when testing for voltage at the battery 
cable, then check again using a chassis ground. Major differances in reading 
means a bad ground connection between the either the starter body and engine 
block, or between the engine and the chassis (ground straps).

 If the starter operates then a 75% chance says the ignition switch or any 
aplicable starter relay is bad. Automatic cars will complicate things with 
park/nuetral safety switches, newer cars complicate it with anti-theft 
interlock systems. Other thing to check at this point is that the small wire 
to the starter is not damaged or broken (multimeter or test light should 
show battery voltage when key is in crank position).

If the starter only makes a "click" noise when you bridge the terminals then 
the solenoid is working (extending the starters gear drive to meet the 
flywheel), but something is preventing it from turning. Again assuming 
better then say 10 volts then 75% chance your starter is bad. Other 
possibilities include a seized starter, a seized engine, bad ground (same 
locations as in the first scenario), or bad constant voltage supply.


Wiring is rarely the culprit except in the totally "duh" cases of a wire 
having simply fallen off of the starter. I even just a few weeks ago had a 
'93 or '94 100LS V6 with a no-starter condition. The ignition switch had 
been replaced less then 30 days prior, so I assumed that something else 
(wiring or interlock relay) had gone bad, but after an entire day I traced 
back to the ignition switch having failed. Turns out it was a super cheapo 
off-brand unit (cost was $3 vs. the usual ~$20), and had simply just gone 
bad after 30 or so days of use.



My percentages are not *ACTUAL* values of course, but theoretical chances 
that I estimate using real-world experiance as a professional mechanic. IME 
on a manual transmission car a no-starter condition has a 99% chance of 
being either a dead battery, dead starter, or bad ignition switch.YMMV, etc.

-Cody Forbes
http://www.5000tq.com
'86 5k noT noQ
'86 5k noT noQ - Parting Out
'87 5ktq
'87 5ktq - Fast. Really Fast.