HVAC Blower Stuck on Low Speed / No Temperature Control - AC Relay Box Connector Unseated

Electricalbeginner✓ OP Confirmed

Problem

HVAC system stopped working properly after gauge cluster removal for speedo cable replacement. Climate control buttons light up and the off button works, but the blower only runs at a very low speed regardless of whether low, medium, or high is selected. Temperature control also non-functional - changing from 65 to 85 produces no change in air temperature even at operating temp.

Blower fan runs at same very low speed on all three settings (low, medium, high)Temperature control has no effect - air stays the same temp regardless of settingClimate control buttons illuminate normallyOff button functions correctlyProblem appeared after gauge cluster removal for speedo cable work

Root Cause

The AC blower speed relay box connector (located behind the gauge cluster, near where the speedo cable work was performed) was barely unseated from its socket - just enough to break the electrical connection. This was likely disturbed during gauge cluster removal.

Confidence

High confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted March 2023 on SupraForums.com