Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSPONTIAC1991FIREBIRD FORMULA, 5.0 F, STANDARD, M39REPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE MECHANICALENGINE COOLING FANTROUBLE SHOOTINGTEST B, COOLING FAN A/C OPEN TEST
1991 Pontiac Firebird Formula, 5.0 F, Standard, M39
Test B, Cooling Fan A/C Open Test
1991 Pontiac Firebird Formula, 5.0 F, Standard, M39SECTION Test B, Cooling Fan A/C Open Test
- Disconnect A/C-heater switch control connector. Install fused jumper between Dark Green wire at connector and ground. Turn ignition on. If cooling fan operates, proceed to next step. If cooling fan did not operate, check Dark Green/White and Dark Green wire from A/C-heater switch to cooling fan relay for open circuit.
- Install fused jumper wire between Dark Green and Black wires of A/C-heater switch control connector. If cooling fan operates, replace A/C-heater switch control. If cooling fan did not operate, check for open circuit in Black wire from A/C-heater switch control to cooling fan.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.