95 LT1 Cooling Fan Troubleshooting

[Pantaz]

The cooling fan never comes on by itself. It does operate if the temperature sender is disconnected.

Here's what I've done so far:
1. Replaced the temperature sender. (And tested the resistance of the sender when cool/hot.)
2. Tested the relays (cooling fan and A/C fan relays).
3. Tested for continuity of the temperature sender yellow wire between the sender and the computer.
4. Tested continuity of the temp sender connector plug.

What am I missing?

[Blue Bowtie]

Scan the PCM to see what the CTS is reporting to it. If the PCM thinks the coolant is below 233ºF, the fan will not turn on. Also, if the PCM thinks the vehicle speed is over 34 MPH, the fan will not turn on.

Does the fan turn on when the air conditioning compressor is on?

[j cAT]

Originally Posted by Pantaz

The cooling fan never comes on by itself. It does operate if the temperature sender is disconnected.

Here's what I've done so far:
1. Replaced the temperature sender. (And tested the resistance of the sender when cool/hot.)
2. Tested the relays (cooling fan and A/C fan relays).
3. Tested for continuity of the temperature sender yellow wire between the sender and the computer.
4. Tested continuity of the temp sender connector plug.

What am I missing?

check PCM connector C1 pins 11 and 10 they ground the fan relay coils that turn on the fans. with a/c on pin11 dark green should be ground.this is primary fan relay coil ground...

[j cAT]

Originally Posted by j cAT

check PCM connector C1 pins 11 and 10 they ground the fan relay coils that turn on the fans. with a/c on pin11 dark green should be ground.this is primary fan relay coil ground...

IF YOU DO NOT HAVE SUFFICENT A/C FREON CHARGE THE FAN WILL NOT COME ON WHEN A/C IS TURNED ON. ALSO FAN WILL COME ON ONLY IF ENGINE TEMP IS 235DEG F EVEN IF YOU HAVE NO FREON. BY REMOVING ECT CONNECTOR PCM IS OPERATING IN FAIL MODE AND FAN IS FORCED ON AS PROTECTION.......

[Veronica Mangan]

Help! I'm lost in the forums...I'm trying to replace the serpentine belt on my 95 chev carpice wagon. It's got the mechanical fan (towing package), and I can't get to one of the 2 nuts on the metal brackets to the metal radiator hose section. Am thinking of taking the radiator hose apart. Any clues? Point me to the appropriate thread in this forum? I only have dial-up at the moment, so any help would be greatly appreciated!

Desperate in Oregon
Veronica

[j cAT]

Originally Posted by Veronica Mangan

Help! I'm lost in the forums...I'm trying to replace the serpentine belt on my 95 chev carpice wagon. It's got the mechanical fan (towing package), and I can't get to one of the 2 nuts on the metal brackets to the metal radiator hose section. Am thinking of taking the radiator hose apart. Any clues? Point me to the appropriate thread in this forum? I only have dial-up at the moment, so any help would be greatly appreciated!

Desperate in Oregon
Veronica

the hd cooling mechanical fans [not electrical powered ] is an odd ball.

you have 2 belts. 2 tensioners one for each belt . one belt is for fan. the other belt is for alternator,power steeriing etc..

rotate the tensioner to reduce tension on the belt to remove..

replace both belts at this time..there is no need to remove any hardware !

if you have no idea how to rotate the tensioner get someone who can .