First off I would like to say hello to everyone. I am a proud first time corvette owner. I have a stock 2005 with 67xxx miles. So far my experience has been amazing. However a few days ago I got a check engine light on my way home. I pulled the codes I have a Stored P1482, and a pending P1482. I look it up in my good 'ol chiltons manual and its the Cooling Fan Speed Output Circuit. Attached in the manual is the procedure for diagnosing, and fixing the problem. However Im running into a problem. step 4 it tells me "4.With a DMM, test for B+ between the B+ circuit terminal 3 and the control circuit terminal 6. If less than B+, test the control circuit for and open/high resistance. If the circuit tests normal replace the ECM." So first I test b+ voltage at the lugs and get 12.5 volts. (that seems good) so then I test the afore mentioned points and get 11.5 volts. (That's a 1v drop.) now my question is (and please forgive me im new to auto repair) is that 1v drop acceptable or does that measurement need to be 12.5 volts as well. Secondly if im still getting voltage to read then the wire couldn't be shorted or open right? if it can how would I test that. and lastly its says test the "control circuit". Im assuming this is the aforementioned control wire and b+? or do I test control wire and ground?. Ive jumped my fan to be sure that works and it does. So my problem is either the ECM,FCM, or a wiring bug. Also I have checked the connector that the harness plugs into and its not melted/ damaged or anything. Also the dmm test of b+ and control wire at the three prong plug also reads 11.5v. please help. whats my next best step.

 

Anyone?

 

ok try a search for melted fan plug there are quite a few threads on this problem. Did you unplug the large two wire plug from the fan motor to the controller? it is on one leg of the fan shroud.
most problems are right there quite a few of us have simply taken the plug out and wired the ends together (crimp connectors or solder and tape)

 

I checked a 3 wire plug that goes to the 5 wire plug that goes into the fan control module. Those are not burnt and look brand new. Your saying there is just a 2 wire conntecor that goes to the fan? I look for it. But I was able to jump the fan and it spun up just fine would that happen if the plugwas bad?

 

yes, the plug is between the controller and the fan. if it is bad when you pull it apart and look in the ends it will show sign of melted plastic

most likely that is where the problem is

 

Ok so there arent 3 connectors there are two. A three prong connector and and the larger connector that goes into the fan module. I pulled them apart and as stated above in my first post they look fine no melting no corrosion. Nothing. When I test the plug with a dmm b+ and the control wire thin little green one I read 11.5 wheb I go back to the battery and test b+ and ground its 12.5 when I test the plug b+ and ground its 12.5 so whats going on is some where in the control line thebplugs arent melted or anything

 

So im unsure of where to go from here.

 

check the relay box under the hood. It may be overheated (the cause of headlight failures) and the root of your voltage drop. Hopefully just needing a new relay and not a new box.

 

Nope the fusebox is pristine and all the fuses are good

 

okay so my train of thought is maybe the connector is bad just not visibly. Im sure the plug can fail well before it melts. My plan is to cut the plug off completely and then use my dmm to remeasure the voltages. Ill let you guys no how it goes

 

I dont have a schematic here with me
I would jumper the relay for the fans and see if they run. If yes then its in the control circuit,(Relay,Temp Switch or ECM). If no bad power feed from relay to fan.
The 1v drop is not a issue, it does indicate resitance in the circuit though

 

Thats where Im at. I have jumped the circuit to test the fans as mentioned in my first post and they spinup just fine. I had wittled it down to the the control circuit. My question is if the 1v is not an issue then in "theory" the control circuit is fine thus wouldnt it just mean the fan control module needs replaced?

 

Because there is no "relay" per say as its a pwm fan through the fan control module

 

if the connection to the cotroller is good for sure then it most likely is thhe controller. I'd splice out the connector (plugs) to make sure before buying a controller.

 

That's my plan I think is to cut the connectors and just hardwire the fan. Retesting all my voltages along the way. Im almost 90 percent sure the fan controller is bad. But there is that nagging 10 percent that something has gone wrong with the ECM. I wish I had a better scanner to manually control the fan for diagnostic procedures