How-to & wiring guides
Practical, GM-specific how-tos from the Helm Dynamics workshop — wiring, configuration and the details that make a swap or install behave like factory. New guides added as we write them.
Wiring the brake inputs to the E38 ECU for cruise control
The E38 won't let cruise control set or hold without valid brake signals. Here's what the ECU expects, how the brake switches wire in, and how to confirm it before you road-test.
Read the guide →Setting up a resistive fuel-level sender
A 2-wire resistive fuel sender wires straight to the Expander — the on-board pull-ups read it, no external resistor. Here's how to wire the sender, pick the range and calibrate it in the dash.
Read the guide →Setting up a cruise control stalk (Nissan Patrol)
A cruise resistor ladder wires straight to the Expander's cruise channel — the on-board pull-up reads it, no external resistor. Includes how to tell an early from a late Nissan Patrol switch, and how to teach the buttons.
Read the guide →More guides on the way
Have a topic you'd like covered? Email the team and we'll add it to the list.
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