no start v6
John Cody Forbes
cody at 5000tq.com
Tue Jul 25 23:22:38 EDT 2006
>> 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.
>> 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.
'86 5k noT noQ
'86 5k noT noQ - Parting Out
'87 5ktq - Fast. Really Fast.
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