Error code reference

Carrier Air Conditioner Error Code 8

Welded Contactor

Carrier codes Carrier air conditioner codes

Welded Contactor — Compressor always runs because contactor has failed closed.

First step from the service manual

Check if compressor contactor has failed closed; verify thermostat demand signal is connected to module.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for 8.

Step-by-step tests with expected resistance, voltage, and continuity values
Wiring diagram references and connector pinouts from the OEM service manual
Verified part numbers when replacement is required

Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

M+

M+ Max·Carrier Air Conditioner

8 on my Carrier Air Conditioner

M+

Welded Contactor — Compressor always runs

From Service Manual 985642, p.14:

1.Check if compressor contactor has failed closed; verify thermostat demand signal is connected to module.

2.Measure control board supply voltage at the test points. Expected: 12 VDC and 5 VDC; a drop below 4.75 VDC on the logic rail points to a failed onboard regulator.

3.Inspect all connectors on the main control for corrosion, thermal stress, or backed-out pins. Reseat each connector with the power disconnected.

Part WPW10804018

Electronic control board

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass

First step from the service manual

Get the full diagnostic procedure for 8.

Related Carrier air conditioner codes