My cousin called me today because her GMC Blazer wasn't turning off. She was asking for me to take her battery out, but I knew the car wasn't going to stop if I did that because the alternator would still be kicking out juice, so I didn't bother doing all of those steps to cut the car off, she still had to drive home.
When the key was turned in the off position the dash lights, heater blow fan, etc would all turn off correctly. When the key was moved to the On position, all the dash lights, blower fan, etc started back up. So that made me rule out the ignition switch being faulty. But it has been 11 degrees and colder the past few days. I kinda figured it was due to the cold and something sticking somewhere.
My question is, what actually makes the car turn off when you move it to the off position? For example, on a lawnmower, the off switch simply grounds the spark plug wire to the chassis ground and short circuits it, so to speak. What exactly happens on a car?
2007-02-08 15:03:27 · 6 answers · asked by SharpGuy 6 in Cars & Transportation ➔ Maintenance & Repairs
the ignition is usually cut off by the switch ......there for cutting power to the ignition at the starter solenoid.........some how the solenoid switch is stuck on the ignition side only.........usually when this happen,s the starter will continue to spin as well......but not alway,s......this is unusual.....but not unheard of........be sure power is cut to the solenoid ....when the switch is turned off......if the engine continue,s to run after that........replace the solenoid.
2007-02-08 16:13:16 · answer #1 · answered by slipstream 7 · 0⤊ 0⤋
You didn't say what year the vehicle was, so I'll cover a few possiblities. None of these are common problems.
An older carbureted GM vehicle has the igniton (distributor hot wire) controlled by either the key switch itself or a relay in the starter solenoid, down low on the passenger side of the engine, controlled by the ignition switch; so it could be frozen/stuck closed. The mechanical fuel pump will continue to work as long as the engine is running, so only one circuit is staying hot - the ignition (distributor hot).
The key switch could still be faulty - just the part that controls the ignition may be messed up, not the part that controls the accessories and lights. These are separate switches inside the ignition switch assembly. One set of switches can work fine while the other is messed up.
On newer fuel injected vehicles, the key switch positon tells the computer to shut off the ignition and fuel pump relays. If the GMC is fuel injected, it's almost certainly a problem with the key switch. The computer/relays would probably not malfunction on both the ignition and fuel circuits at the same time.
2007-02-08 23:21:19 · answer #2 · answered by bobo383 3 · 0⤊ 0⤋
Shouldn't rule out the ignition switch..there are actually 3 switches in 1.. 1 is to start..1 is to run and 1 is for accessories.. Had the same thing..without starting it...just turn the ignition back and forth several times pushing in and out... Can get a little more life out of it..until you get a new one..
2007-02-08 23:08:57 · answer #3 · answered by cammiecover 1 · 0⤊ 0⤋
You cut the flow of electricity to the computer and ignition system. It is probably the ignition switch, and it is worn out inside.
2007-02-08 23:08:43 · answer #4 · answered by atcranes 3 · 0⤊ 0⤋
Turning the key off kills the power to the ignition.
Disconnecting the battery will kill all power to the vehicle. Alternators will not put out any power unless they have exciter voltage from the battery.
2007-02-08 23:10:53 · answer #5 · answered by R1volta 6 · 0⤊ 2⤋
AAUGH! It's CHRISTINE! RUN!!!!
Maybe it's carbon build up with the pistons.
2007-02-08 23:12:09 · answer #6 · answered by ANSWER MY QUESTION!! 6 · 0⤊ 0⤋