Depending on engine the solenoid is located on the either the firewall or the starter. You can usually follow the neg. battery cable (black) to it. Be sure to disconnect battery when changing this part.
It is in the starter.
The solenoid is part of the starter.
It is on the starter.
The Starter solenoid is located on the starter itself.
The 1994 Jeep Grand Cherokee ERG solenoid is located on the firewall of the engine compartment. The solenoid will be on the passenger side of the firewall.
The shift solenoid is inside the transmission on the valve body.
It's attached to the starter.
Starter solenoid is on the starter, trans solenoid is on the trans.
Usually the solenoid is mounted on the starter on newer vehicles. There are exceptions, however. The easiest way to tell is to look at the starter. If the solenoid is mounted on it, it will be a smaller cylinder shaped object with one large wire and one or two smaller wires attached to the end of it.
On the starter
above the starter
There is a solenoid pack inside the trans on top of the valve body.
It is located on the lower drivers side rear of the engine.