red wire on the shift solenoid

1994 DODGE CARAVAN
160,000 MILES • 3.3L • 6 CYL • FWD • AUTOMATIC
Avatar
DODGEPODGE
  • MEMBER
  • 111 POSTS
should it be hot all the time or would it be a different wire?
Feb 20, 2017 at 3:16 PM
Advertisement
Avatar
CARADIODOC
  • CERTIFIED EXPERT
  • 34,306 POSTS
There are multiple red wires. The one feeding the solenoid pack gets twelve volts from the transmission control relay. That gets turned on at the same time as the automatic shutdown, (ASD) relay turns on.

What kind of problem are you trying to solve?
Feb 20, 2017 at 4:58 PM
Avatar
DODGEPODGE
  • MEMBER
  • 111 POSTS
there might be multiple red wires but not going to the shift solenoid. there is only one red wire going to the shift solenoid connector on mine. and it is not hot. so where is the ASD and how do i check it? where is it located? what purpose does it serve? thanks
Feb 21, 2017 at 10:15 AM
Advertisement
Avatar
CARADIODOC
  • CERTIFIED EXPERT
  • 34,306 POSTS
The Engine Computer turns on the automatic shutdown, (ASD) relay for one second when the ignition switch is turned on, then again during engine rotation, (cranking or running). That relay sends current to the ignition coil(s), injectors, alternator field, oxygen sensor heaters, and fuel pump or pump relay. The computer knows the engine is rotating by the signal pulses it receives from the crankshaft position sensor and the camshaft position sensor.

If a fuel line is ruptured in a crash, there will be no fuel pressure, and the engine will stall. Once stalled, there will be no signal pulses, so the computer will turn the ASD relay off. That stops the fuel pump from dumping raw fuel onto the ground where it would create a fire hazard.

If the engine runs, the ASD circuit is working, and there's nothing to check there.
Feb 21, 2017 at 4:27 PM
Avatar
DODGEPODGE
  • MEMBER
  • 111 POSTS
i dont know why you mentioned the asd in the same sentence as the trans control relay ? that confused me. i'm trying to figure out why the red wire to the trans shift solenoid is not hot ? and if thats not hot thats why my shift solenoid is'nt working and trans isnt shifting.i tried switching out the relay with another one and that did'nt solve the problem. so i'm baffled here ?
Feb 23, 2017 at 12:05 PM
Avatar
CARADIODOC
  • CERTIFIED EXPERT
  • 34,306 POSTS
You asked how to check the ASD relay. I told you it's working if the engine runs, and I added why it's used and how it works. It is turned on at the same time as the transmission control relay, and by the same circuit. The red wire you asked about gets 12 volts switched onto it by the transmission control relay.
Feb 23, 2017 at 5:21 PM