HI, everyone
My problem is with a cooling fan.
About a week ago I noticed the my cooling fan would not come ON while I have AC ON or at high Temp. I checked the fuse #40 (good), I checked the relay #50 (good). Its clicking when the PCM request the fan. I had over 14 volts at the wiring harness at the fan connection.
So I thought I needed an new fan.
I bought a new fan and installed it. SAME PROBLEM. Fan will not run.
So I thought What if , just may be I have a bad ground connection, since I did have a voltage reading at the harness.
SO I got a piece of a wire and tapped into a ground (black wire) at the fan harness and then connected that wire direct to the chassis.
Now the fan works just like it should. AC ON, fan is ON,. Temp goes to 217F fan comes ON.
SO it looks to me like I had a bad ground connection.
MY question is : Does anyone knows where is ground connection for cooling fan on chassis? I do not think there is a fuselink on ground wires. Am I right?
I cleaned 4 ground connections that I found under the hood. 1st to the left of Oil filter. 2nd just behined frond driver head light. 3rd above the Thermostat and 4th in front of driver side strut tower. Cleaning did not helped. I did not cleaned the 5th ground that is to the left of driver strut tower.
Fan only works with my direct ground connection. I want to fix it right so if any one knows where is the connection please let me know.
If you have any other thought please feel free to share.
Thank you.

 

2.2L



(1) C160
(2) Engine Valve Cover
(3) Fuse Block - Underhood C1
(4) C101
(5) S103
(6) C100 (MN5)
(7) G107
(8) G105

2.4L



(1) Engine Cover
(2) S103
(3) C101
(4) Fuse Block - Underhood C1
(5) Engine Control Module C2
(6) Engine Control Module C3
(7) C160
(8) Intake Manifold
(9) G105

 

Thank you Chevy MGR
That diagram will help alot.

 

I know this is an ancient thread but after replacing my engine I had exactly the same situation as the OP, so here is how I fixed it.
I had installed the ground connection below the alternator and tightened the bolt snug. The problem was that the bolt bottomed out before the ring terminal used for the ground was snug under the bolt head, leaving a loose / no ground connection. Using a 1.25 thread pitch x 8 mm dia shoulder bolt 16 mm in length instead did the trick. The bolt that didn't work was 20 mm length.
Maybe this will help someone else...