Chrysler Repair/no 12volt for ignition
hi my 95 chrysler newyorker 3.5 24valve engine has no 12volt for ignition the green and orange wire that comes out of the back of alternator that powers the ignition is dead iv checked all the fuses ,replaced the camshaft rotation sensor, replaced the alternator .if i run a jumper from the battery to the green orange wire on back of the alternator it will start and run perfect i cant find a crankshaft sensor i dont think it has one when i put 12 volts to the green orange wire back of alternator i can it it sounds like a pump for a second or 2 what am i missing thankyou
That is interesting because by jumping to the dark green/orange you are filling in for an 'open" autoshutdown relay or a blown fuse that supplies it. The autoshutdown and the fuel pump relays should close for about a second or so when you turn the key to run, and then close again when you try the starter IF both rotational sensors are putting out acceptable signals.
Yet, the engine does run when you by-pass the auto shutdown relay which it presumably shouldn't do because the pulsing from the rotational sensors are not good enough to keep the ASD closed (those sensors say to the computer it is safe to keep the spark and fuel powered up, otherwise the ASD will not close).
There is a crank sensor on the right side of the engine at the flex plate/rear of the engine located just above the top surface of the transmission.
You could try doing a fault code readout using the ignition switch:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the check engine light, which remains on to see it begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat the process to be sure of an accurate set of flash counts. Tell me the counts in order of appearance. If you get 1,1 that is code 11 which says the computer is not satisfied with the crank sensor pulses.
To get to the sensor you would find it easier to go in from underneath on the right side. You can measure for the pulses from the sensor between pin 4 and 24 of the pcm where you should see voltage oscillate between 5 and 0.3v as you rotate the engine by hand using a socket and handle on the crankshaft front pulley bolt and with the ignition switch in the run position.
You could try switching out the ASD relay with say the compressor clutch relay next to it to see if the relay is bad. And look at fuse B (20 amp) in the same box to make sure it doesn't have a subtle crack in its wire. That is the fuse that sends the current to the ASD points to then be sent on to the spark coil and fuel injectors.
Let me know what you learn.
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