Air heaters often use a simplified loom for standard controllers:

, the 6-pin main connector (X1) typically follows this assignment:

: Plugs into the 4-pin "Telestart/Diagnose" connector.

: No connection (Standard) or Input for Auxiliary/Parking heating (RV/HD models).

For a useful guide on the , focus on the specific pinouts for your heater model, as miswiring sensitive electronics can lead to damage. Webasto Thermo Top C/E Pinout (6-Pin Connector X1) For liquid heaters like the Thermo Top C Go to product viewer dialog for this item.

: Ensure a 20A fuse is in the main heater slot (F1) and a 5A fuse for the multi-controller. Quick Connection Tips Webasto Thermo Top C Workshop Repair Manual

: W-bus (Yellow wire) — used for digital communication and PC diagnostics .