Both fans not kicking on.
08-05-2012, 12:14 AM
#5
So, I have learned that both fans are either on or off at the same time if they are working correctly. The fans are wired and controlled in a parallel/series configuration.
I stand corrected.
08-05-2012, 04:03 PM
#6
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Member Since: Jul 2012
Location: LOMITA CA
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Have to dig deeper.
Fuses good and installed a new relay but no fan at 230f. On top of that the oil pressure gauge stays peged at 80 until the temp reaches 225f and then drops to zero. Wtf. Any ideas on my next probe.
08-05-2012, 08:50 PM
#7
Thanks
08-06-2012, 02:49 PM
#9
Racer
1st-c5 listen to 8vette7. I had the same issue you are having now. I read probably 2 dozen threads most of which he commented on. His tips finally paid off. In my case it was a bad fuse (#49) but I was counting the fuse positions incorrectly in the box. One 30amp fuse later and I was off to the races! Thanks for the help by the way 8VETTE7 even though you didn't realize you were helping at the time.
08-07-2012, 10:03 AM
#11
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skills
8vette7, thanks for taking interest in my case. I restore cars for a hobby. I can r and r anything. I just sold my 57 chevy and a 73 mustang mach 1 that i braught back to life. I now have a 70 chevelle ss clone with a 454 t400. This car is a long term project. Now you have guessed that i have no problems with older cars. The computer car is a different critter. As for tools i have everything but a welder. My diagnostic skills are weak though. I finally got the heat up to 235 ish when both fans kicked in. Thats when the check engine light flashed and the buzzer started .
08-31-2012, 10:45 AM
#14
Drifting
Hi V8VETT7
Just read thru your posts, and I'm having the same (no low speed fans).. Nor hi speed at 235+. I do have fans at seming correct temps with air con on.
Fuses are good
Relays are good
Low speed (dr side fan only) when I jump the low speed relay (30-85 poles).
Hi speed ( both fans) will activate when jumping hi speed relay.
I do not get any voltage/ground cont to the relays ground ( guessing it's the activation lead for the relay ) pin 87? With temps above 230+. Pin 86 hot all the time as is pin 30.
Dose the temp sender in the drivers side head control only the fans or is it sending single DCI. and fans?
I'm stumped.
Just read thru your posts, and I'm having the same (no low speed fans).. Nor hi speed at 235+. I do have fans at seming correct temps with air con on.
Fuses are good
Relays are good
Low speed (dr side fan only) when I jump the low speed relay (30-85 poles).
Hi speed ( both fans) will activate when jumping hi speed relay.
I do not get any voltage/ground cont to the relays ground ( guessing it's the activation lead for the relay ) pin 87? With temps above 230+. Pin 86 hot all the time as is pin 30.
Dose the temp sender in the drivers side head control only the fans or is it sending single DCI. and fans?
I'm stumped.
Last edited by Moto One; 08-31-2012 at 10:48 AM.
08-31-2012, 05:26 PM
#15
Team Owner
Hope the results get posted up on what is found.
Nice job 8VETTE7....
09-01-2012, 05:20 PM
#17
Team Owner
I spoke to Moto One this morning and he does have a setup that allows him to bench test the relays. All 3 are operating correctly in a bench test. The 3 fuse for the fans are all good as well. Reference the wiring diagram in post #13
However, the fans do not come on in low speed mode correctly. The testing done showed that the ground that the PCM should provide for both low speed mode and high speed mode does not seem to occur. The temperature guages operate so the temp sensor is functioning. At this point the plan is to inspect the wiring at the PCM for damage and/or corrosion. If the wiring from the PCM to the relays proves to be in tact then the problem is likely within the PCM. Moto One has promised an update once he completes the wiring inspection.
However, the fans do not come on in low speed mode correctly. The testing done showed that the ground that the PCM should provide for both low speed mode and high speed mode does not seem to occur. The temperature guages operate so the temp sensor is functioning. At this point the plan is to inspect the wiring at the PCM for damage and/or corrosion. If the wiring from the PCM to the relays proves to be in tact then the problem is likely within the PCM. Moto One has promised an update once he completes the wiring inspection.
Thanks for the update......
09-02-2012, 10:21 PM
#18
Drifting
Well, I dough deeper down into the ECM and wiring under the battery and unless GM packs the area with Dog hair and pink insulation, I would guess that I have had at one time or another some Micky Mouse living there. After inspecting the wiring and seeing that there was no evidence of rodents eating the wiring I unplugging all the connectors that were visible and repluged them. I now have low speed fans but not until the temp has reach about 235. they go off at 220. Its never got the temp above 235 so Im not sure if the high-speed fans come on. (They (high-speed)will come on if the Air Con is on at 225.)
A big thanks to 8Vette7 for taking time away from hanging out at the pool for all his help.
Mark.
A big thanks to 8Vette7 for taking time away from hanging out at the pool for all his help.
Mark.
Last edited by Moto One; 09-03-2012 at 07:37 PM.
09-08-2012, 03:46 PM
#19
Seems you guys may know the answer...Fan Problem
My C5 is running hot as well and has the same check engine code come on about every other time i start it. Oil and coolant temps reaching 240
Diagnostic Steps so far:
I replaced Maxifuse 49 which was blown.
Maxifuse 46 is still good
I replace relay 44 (Black 4 prong)
When i pulled relay 43 with car running the right (passenger side) fan stopped running.
I can't see the left (driver's side) fan to tell if it is running or not.
Next i was considering replacing relay 45 (grey 4 prong)...
Thanks in advance
Diagnostic Steps so far:
I replaced Maxifuse 49 which was blown.
Maxifuse 46 is still good
I replace relay 44 (Black 4 prong)
When i pulled relay 43 with car running the right (passenger side) fan stopped running.
I can't see the left (driver's side) fan to tell if it is running or not.
Next i was considering replacing relay 45 (grey 4 prong)...
Thanks in advance
09-08-2012, 06:37 PM
#20
Thanks for the reply. maxifuse 49 has blown again...i don't have the tools or know-how to check and clean up all grounds at the moment. It's scheduled to be looked at Monday so i'll have them look at the grounds as well.
thanks
thanks