Where is the torque converter clutch solenoid on a 1988 Chevy G20 conversion van?

The torque converter clutch solenoid on a 1988 Chevy G20 conversion van isn't located in a single, easily accessible spot like a standalone component. It's an internal part of the transmission's valve body. You won't find it by looking under the hood or in the transmission pan without disassembling the transmission.

To access it, you'd have to:

1. Remove the transmission: This is a major undertaking requiring significant mechanical skill and specialized tools.

2. Disassemble the valve body: Once the transmission is out, you'd need to carefully disassemble the valve body, which houses the various solenoids and internal valves. The TCC solenoid is usually found within the valve body assembly, often nestled amongst other components. A workshop manual specific to your transmission type (e.g., THM700R4, TH400, etc. – you'll need to determine which your van has) will be essential.

In short: There's no "here's where it is" answer. It's internal to the transmission and requires professional-level mechanical knowledge and tools to access. If you suspect a problem with your torque converter clutch solenoid, it's best to take your vehicle to a transmission specialist.