question for ya I have a 1991 mustang gt comvertible my ignition turns without a key last time it was on the road about 2010 if it sat over night id need a jump start every morning this was with a used auto wrecker battry since then I have bought a new battery but kept it un hooked and only hooked it up to idle the car once a month im putting it back on road in next couple months could the fact that it turns without a key be draining the battery ? I am planning to fix the issue but just wondering if I should look elsewhere for the battery drain issue
The lock cylinder is probably not your problem .
the best way to check for parasitic drain is
connect an ammeter in series with the battery's
neg terminal and the neg cable. If the ammeter
reads between 25 and 50 milliamps then there is
too much drain. You can start to narrow it down
by unplugging things one at a time and check meter
to see any drop in current.