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Need wiring diagram for A/C '86 SE V6 by sleevePAPA
Started on: 05-05-2013 03:13 PM
Replies: 7 (881 views)
Last post by: dalton on 06-24-2014 02:28 PM
sleevePAPA
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Report this Post05-05-2013 03:13 PM Click Here to See the Profile for sleevePAPASend a Private Message to sleevePAPAEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ive looked around but most of the downloads I find are for the '84. Thanks to the LV Fiero Club VP, found that after my 7730 swap somehow something was goofed even though I followed the swap info from sinister. The A/C system functioned properly with the 7170 ECM. Also found the flyback resistor on the compressor clutch plug was broken off, ugh. I need to replace the plug with another one, and make sure the ECM is triggering the clutch relay like it should. Im looking for the complete A/C system wiring diagram so I dont mess anything up. Also, the trigger wire from the ECM(iirc F1 on the 7730) is a ground trigger, right? Im also swapping in another 7730 after Im completly sure that the wiring is GTG.

Thanks
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Report this Post05-05-2013 05:02 PM Click Here to See the Profile for CowsPatootClick Here to visit CowsPatoot's HomePageSend a Private Message to CowsPatootEdit/Delete MessageReply w/QuoteDirect Link to This Post
http://cowspatoot.com/fiero...0-%20AC%20system.pdf

There is a stack of other diagrams at http://cowspatoot.com/fiero/wiring in case that one doesn't get everything you need.
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sleevePAPA
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Report this Post05-11-2013 07:34 PM Click Here to See the Profile for sleevePAPASend a Private Message to sleevePAPAEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks cows patoot(lol).

the wiring diagram came in handy to test the A/C clutch relay and if the ECM is triggering it.

found the flyback diode was missing from the a/c clutch plug, replaced it with a new one.

just tried triggering the relay and the relay closes, but doesnt excite the clutch.

measured voltage across the the relay and found 12.7V at the black/wht stripe wire(to the high pressure switch?) and 12.7V at the green wire going down to the clutch.

so im at a loss right now, only thing I can figure is there is a short in the clutch coil, the relay seemed to be heating up pretty good. thats the only thing I can figure.

the A/C worked last fall before I swapped to the 7730 ECM, so something happend between then and now. I know for sure that the ECM is actuating the relay though.

Any ideas?

Thanks!
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Report this Post05-11-2013 09:49 PM Click Here to See the Profile for sleevePAPASend a Private Message to sleevePAPAEdit/Delete MessageReply w/QuoteDirect Link to This Post
does the 7170 ECM ground the circuit at pin C2???

figured out that the high pressure switch is toast, any harm in bypassing it?

*edit* nevermind for Q#1.

Im using $8D and it uses switches to control the relay, not the ECM itself(i think). Whats funny is, switching the HVAC controls does energize the circuit at pin F1 on the 7730, so instead of grounding it actually sends 12V. Im thinking its something in the code that needs to be changed. Ugh....

[This message has been edited by sleevePAPA (edited 05-11-2013).]

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Report this Post05-12-2013 12:24 AM Click Here to See the Profile for sleevePAPASend a Private Message to sleevePAPAEdit/Delete MessageReply w/QuoteDirect Link to This Post
$8D does NOT control A/C clutch relay, so a patch must be written. That is all for now....
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Report this Post05-12-2013 05:03 AM Click Here to See the Profile for CowsPatootClick Here to visit CowsPatoot's HomePageSend a Private Message to CowsPatootEdit/Delete MessageReply w/QuoteDirect Link to This Post
You can bypass the ECM by simply grounding the blue wire (that originally went to C2 at the ECM). This will allow your AC to work, but obviously will eliminate the ECM's ability to control it. The relay will still be controlled manually by the HVAC controls in the dash. This is how the carb guys do it if they want to keep their AC.

I refuse to answer the high pressure switch question...I am not an AC expert. As long as you never hit a high pressure situation, then it should be safe to bypass it...but since I am not an expert, I can't tell you how common that situation is.
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Report this Post05-12-2013 10:22 AM Click Here to See the Profile for sleevePAPASend a Private Message to sleevePAPAEdit/Delete MessageReply w/QuoteDirect Link to This Post
just found out that the 7727 $8D has the controls(corvette). Trigger wire is supposed to be at F3

*edit* It works now, splice into E8 with added pin at D3.

[This message has been edited by sleevePAPA (edited 05-12-2013).]

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dalton
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Report this Post06-24-2014 02:28 PM Click Here to See the Profile for daltonClick Here to visit dalton's HomePageClick Here to Email daltonSend a Private Message to daltonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Cannot seem to reach cowspatut. Really need some good 87 Fiero HVAC wiring schematics. Someone at some point snipped all the wires to the connector plugs, and removed the HVAC relay in the engine compartment. I have to recreate all this. Any help with this would be greatly appreciated.

------------------
Ed Konda
1475 Southwood Road
Severn Bridge, ON
P0E1N0
705-345-6982
ed@ontariokitcarbuilders.com

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