Haynes mistake?
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Le Mans Master
Joined: Oct 2003
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From: seattle WA
Haynes mistake?
Myself and another member responded about a fan problem on what we were led to believe was an 84. I quoted out of the Haynes manual 84-91 that the fan is controlled by the ECM during operation of the AC-page 100 #11, the other member who owns an 84 said the fan is not controlled by the ECM-is this a mistake or? :confused:
Le Mans Master
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From: San Diego, Ca
Re: Haynes mistake? (rick lambert)
Main fan is controlled by the ECM. If the a/c is on, it's gets it signal for the fan switch on the high pressure line; otherwise signal is from the coolant temp sensor.
Safety Car
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From: Charleston SC
Re: Haynes mistake? (rick lambert)
The Fan on a 84 is not controled by the ECM. It is directly controled the the Temp switch on the passangers side head. The fans do come on when the AC is turned on but I do not see where the ECM has a controll signal for this. The only controll I see for the ECM is the white connector pin 21 A/C Functtion control switch, and I thought that was for the A/C clutch but mabey it also controls the fan relay
[Modified by 84LT1, 11:44 AM 5/9/2004]
[Modified by 84LT1, 11:44 AM 5/9/2004]
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From: The Top of Utah
Re: Haynes mistake? (rick lambert)
Myself and another member responded about a fan problem on what we were led to believe was an 84. I quoted out of the Haynes manual 84-91 that the fan is controlled by the ECM during operation of the AC-page 100 #11, the other member who owns an 84 said the fan is not controlled by the ECM-is this a mistake or? :confused:
Main fan is controlled by the ECM. If the a/c is on, it's gets it signal for the fan switch on the high pressure line; otherwise signal is from the coolant temp sensor.
The wiring schematic in my Helms manual, clearly shows circuit #335, spliting at a connector under the hood. One, .5 tan wire goes to the a/c compressor. The other a .8 brown wire goes to the temp switch in the right head between the #6 and #8 spark plugs. Either device can ground circuit #335 and turn the fan on. Circuit #335 plugs into another connector and comes out as a single, .5 dark green wire, which connects to terminal "B" at the fan relay plug. It's funny how the schematic conforms to how MY car is put together. There is Zero, Ziltch, None, NimoNetz, NO, ECM involvement in the fan operation on MY original car.
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Safety Car
Joined: Dec 2002
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From: Charleston SC
Re: Haynes mistake? (CFI-EFI)
.5 tan wire goes to the a/c compressor. The other a .8 brown wire goes to the temp switch in the right head between the #6 and #8 spark plugs. Either device can ground circuit #335 and turn the fan on. There is Zero, Ziltch, None, NimoNetz, NO, ECM involvement in the fan operation on MY original car.
[Modified by 84LT1, 12:34 PM 5/9/2004]
Thread Starter
Le Mans Master
Joined: Oct 2003
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From: seattle WA
Re: Haynes mistake? (84LT1)
CFI-EFI, no offense meant, I just wanted to know if the information I gave to someone else was a Haynes mistake or? You're right, Haynes is a you get what you pay for-Although not bad for 18-20 bucks, I too have the Helms service and electrical manuals about 100 new. I think just a little confusion-it does say with the AC operating. :)
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From: The Top of Utah
Re: Haynes mistake? (84LT1)
The 1.0 dark green, circuit 59, runs from the compressor directly to the "hi pressure cutout switch". That is the sum total of circuit 59. I wasn't prepared to trace every circuit in the car to see if the fan and ECM might somewhere, somehow have a wire that share a conduit. IF the ECM is involved in the compressor operation it is certainly coincidental to fan operation. That is like saying that since the ECM runs the engine, then the ECM is responsible for the heat that closes the temp switch. I stand by my original statement.
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Race Director
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From: The Top of Utah
Re: Haynes mistake? (rick lambert)
CFI-EFI, no offense meant... I too have the Helms service and electrical manuals about 100 new.
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Thread Starter
Le Mans Master
Joined: Oct 2003
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From: seattle WA
Re: Haynes mistake? (CFI-EFI)
:chill: :chill: :chill: In the other post I stated mine was an 87. The information came as a direct quote from Haynes 84-91 regarding fan controlled by ECM when in AC operation. I simply wanted to know without sarcasm if this was incorrect-since no one wants to pass off bad info to others.
:rolleyes:
:rolleyes:
Le Mans Master
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From: San Diego, Ca
Re: Haynes mistake? (rick lambert)
Wow - your '87 is as described with an ECM driver controlling fan operation under both conditions. The '84 supplies a direct ground through the fan switch for non a/c operation. That wire is spliced to the a/c control circuit which is driven (or grounded by the ECM) so the fan will operate when the a/c clutch is engaged. There should be another switch in that circuit to turn off the compressor, or break the circuit so that neither operates 100% of the time. A constantly running a/c compressor isn't efficient, nor is one that doesn't have air blowing across the condensor (regardless of coolant temp). In any event, what do you or your friend need help with?
Thread Starter
Le Mans Master
Joined: Oct 2003
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From: seattle WA
Re: Haynes mistake? (SunCr)
SunCr, it was in response to 84Lt1, fan problems, bottom of this page. I just gave him info out of Haynes. We found out later he has a 94 or 95, just forgot to change his sig. :seeya
Pro
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From: Oz
Re: Haynes mistake? (84LT1)
.5 tan wire goes to the a/c compressor. The other a .8 brown wire goes to the temp switch in the right head between the #6 and #8 spark plugs. Either device can ground circuit #335 and turn the fan on. There is Zero, Ziltch, None, NimoNetz, NO, ECM involvement in the fan operation on MY original car.
But doesn't the ECM control the A/C Clutch with wire #59 DK GRN that goes to ECM pin 21 (White connector) and this is what causes the AC compressor .5 tan wire to become active? If so the ECM would indirectly control the fan relay through the A/C compressor. If I follow the signal flow correctly "If you turn the A/C on then the ECM sends the signal to the A/C compressor which inturn turns on the cooling fan"
[Modified by 84LT1, 12:34 PM 5/9/2004]
But doesn't the ECM control the A/C Clutch with wire #59 DK GRN that goes to ECM pin 21 (White connector) and this is what causes the AC compressor .5 tan wire to become active? If so the ECM would indirectly control the fan relay through the A/C compressor. If I follow the signal flow correctly "If you turn the A/C on then the ECM sends the signal to the A/C compressor which inturn turns on the cooling fan"
[Modified by 84LT1, 12:34 PM 5/9/2004]
Nope, that dk. grn wire on pin 21 tells the ecm that the a/c clutch is energised, so the ecm knows to bump up the idle to compensate for the added load.
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From: The Top of Utah
Re: Haynes mistake? (ben73)
Nope, that dk. grn wire on pin 21 tells the ecm that the a/c clutch is energised, so the ecm knows to bump up the idle to compensate for the added load.
Thanks, Ben
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PS. Quoting from an incorrect source doesn't change how it works.
