cooling fan runs all time, wiring question.
04-18-2016, 05:23 PM
#1
Burning Brakes
Thread Starter
cooling fan runs all time, wiring question.
My cooling fans run all the time. I found the prior owner tied together the blue and green wires together at the cooling fan relays. .
I untied them and they still run all the time.
Anyone know where they may have wired the fans to run all the time at?
Thanks.
I untied them and they still run all the time.
Anyone know where they may have wired the fans to run all the time at?
Thanks.
04-18-2016, 05:47 PM
#2
Melting Slicks
Did you remove the AC?
04-18-2016, 06:25 PM
#3
Is this your ZR-1? What year is it? Some years have 3!
Last edited by WVZR-1; 04-18-2016 at 06:28 PM.
04-18-2016, 06:46 PM
#4
Team Owner
Member Since: Oct 2004
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St. Jude Donor '05
x2 on the AC
Check your connector where it would go to the compressor
Check your connector where it would go to the compressor
04-18-2016, 07:40 PM
#6
Depending on the "YEAR" AC might only turn on the primary (depends upon criteria), if various ECM codes are set yes it defaults to "the pair on". It's like most things YEAR & ENGINE MIGHT MATTER
04-18-2016, 08:00 PM
#7
Drifting
I was assuming it is the 92 ZR1. All obd1 from 86 to 93 use the ecm to control the primary and the secondary has 2 caveats. switch in head for 86 thru 89 and programmed ecm temps or the ac switch.
04-18-2016, 08:13 PM
#8
I've no idea what year his ZR-1 is (I just recall passing some information on to him some time ago) and he didn't actually mention so who knows what it could be .......
04-18-2016, 08:58 PM
#10
04-18-2016, 10:54 PM
#11
Burning Brakes
Thread Starter
*edit* I have the 1992 service manual. I see the compressor under the air horn/throttle body but besides that nada.
Last edited by pushrod-v8; 04-18-2016 at 11:47 PM.
04-19-2016, 04:11 AM
#12
See the cooling fans section in driveability 6E3-C12 of course for VIN J engine and the wiring diagrams in 8A-31-1 again for VIN J. The combination of those sections should allow you to maybe sort the issue.
I'd say you need to have it scanned for ECM codes also. Do you have a GM PROM or someones "tune" on a PROM or maybe an "add-on" card? Was it a DIY tune?
I don't know that you could go directly to the AC and assume it's the issue.
You should be able to do the AC diagnostics from the C68 control panel. You mention it works so does the green LED flash or is it steady on? If flashing - codes?
Start at 1C1-1 for C68 diagnostics.
See 1B-26 for some AC cooling fan info.
I'd say you need to have it scanned for ECM codes also. Do you have a GM PROM or someones "tune" on a PROM or maybe an "add-on" card? Was it a DIY tune?
I don't know that you could go directly to the AC and assume it's the issue.
You should be able to do the AC diagnostics from the C68 control panel. You mention it works so does the green LED flash or is it steady on? If flashing - codes?
Start at 1C1-1 for C68 diagnostics.
See 1B-26 for some AC cooling fan info.
Last edited by WVZR-1; 04-19-2016 at 04:51 AM.
04-19-2016, 06:29 AM
#13
Safety Car
Couple of basic assumptions here: by running continuously you mean the fans run whether the engine is on or off, the fans are rewired correctly, etc.
If that's true, there's a chance the relay is 'stuck'. IIRC it's on the drivers side wheel well of the car. The only reason I suggest that is last year while doing some pm I was insuring the connectors I could get to were tight on the respective relays. I think it was the one of the drivers wheel well I pressed on the top while pulling the connector tight and the top of the relay apparently depressed a little. When it did the fan came on even though the engine wasn't running. Soon as I released pressure on the top of the relay, the fans quit running.
Just a thought/possiblity.
If that's true, there's a chance the relay is 'stuck'. IIRC it's on the drivers side wheel well of the car. The only reason I suggest that is last year while doing some pm I was insuring the connectors I could get to were tight on the respective relays. I think it was the one of the drivers wheel well I pressed on the top while pulling the connector tight and the top of the relay apparently depressed a little. When it did the fan came on even though the engine wasn't running. Soon as I released pressure on the top of the relay, the fans quit running.
Just a thought/possiblity.
04-19-2016, 07:37 AM
#14
Burning Brakes
Thread Starter
Thanks for the help. The fans come on when I start the car. I will try and get this corrected today and will update this thread later.
Car has no trouble codes and the prom was professionally done.
Car has no trouble codes and the prom was professionally done.
Last edited by pushrod-v8; 04-19-2016 at 07:39 AM.
04-19-2016, 10:17 AM
#15
Safety Car
Just one more possibility.
04-20-2016, 03:49 PM
#16
Safety Car
The A/C fan-request switch is on the high pressure line (the small diameter aluminum line), inboard of the RF shock absorber. One dk green, one black wire. (There is another switch adjacent to it with 2 lt green wires. This is NOT the fan-request switch). When the fan-request switch is CLOSED= no fan. When hi pressure = 245Kpa, switch opens, and ECM commands fan = ON.
Remove the connector from the switch. Jumper the two terminals. If the fan goes OFF, the switch has failed open. You need a new fan request switch. I've replaced several of these for this same symptom.
You can change the switch without evacuating the refrigerant system. There is a Schrader valve under the switch. Beware there are two types of this switch. On is NC, the other NO. I helped a friend with this on his 90 LT5, he had the incorrect switch.
Remove the connector from the switch. Jumper the two terminals. If the fan goes OFF, the switch has failed open. You need a new fan request switch. I've replaced several of these for this same symptom.
You can change the switch without evacuating the refrigerant system. There is a Schrader valve under the switch. Beware there are two types of this switch. On is NC, the other NO. I helped a friend with this on his 90 LT5, he had the incorrect switch.
I'm curious, if the problem was the switch, wouldn't simply disconnecting the switch shut down the fan? If it did, that would be a simple test to prove or disprove if that's the cause of the problem.
Just a thought.
04-21-2016, 08:46 AM
#17
Burning Brakes
Thread Starter
I checked the wiring at the a.c. lines on the passenger side and it was not modified. I will do the above mentioned procedure and see if that works.
Thanks again.
Thanks again.