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87 Fiero AC stays on by svocal
Started on: 10-04-2019 02:19 PM
Replies: 24 (287 views)
Last post by: svocal on 10-11-2019 05:57 AM
svocal
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Report this Post10-04-2019 02:19 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Guys...
I need your help on this one. As soon as i turn on the ignition, the AC turns on. Even in the off positions, it stays on.

1. How can I disable it temporarily? fuse breaker? which one is it?
2. Where should i check to find the root of the problem?
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olejoedad
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Report this Post10-04-2019 03:08 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would suspect that the relay for the clutch is stuck in the ON position.
The relay is located in the engine compartment, to the left of the driver side hinge box.
There are two relays there, the one with the ORANGE wires id for the fuel pump, the other one is for the A/C clutch.
Disconnect the plug to the relay and please report back.
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svocal
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Report this Post10-04-2019 11:38 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post

I disconnected the relay you suggested, but the AC still turns on. I even disconnected the other relay just for giggles. The same result.
Any other suggestions?

 
quote
Originally posted by olejoedad:

I would suspect that the relay for the clutch is stuck in the ON position.
The relay is located in the engine compartment, to the left of the driver side hinge box.
There are two relays there, the one with the ORANGE wires id for the fuel pump, the other one is for the A/C clutch.
Disconnect the plug to the relay and please report back.


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msweldon
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Report this Post10-05-2019 12:09 AM Click Here to See the Profile for msweldonClick Here to Email msweldonSend a Private Message to msweldonEdit/Delete MessageReply w/QuoteDirect Link to This Post
It may stay on but does it ever cycle on its own?

Does the ac run when the clutch connector is pulled?

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svocal
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Report this Post10-05-2019 12:31 AM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yes..As soon as i turn the ignition key, it just starts blowing air. Even after I disconnect the relay.
[


QUOTE]Originally posted by msweldon:

It may stay on but does it ever cycle on its own?

Does the ac run when the clutch connector is pulled?

[/QUOTE]

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Rexgirl
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Report this Post10-05-2019 03:06 AM Click Here to See the Profile for RexgirlSend a Private Message to RexgirlEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you mean the cabin FAN runs all the time, that is normal.
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olejoedad
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Report this Post10-05-2019 07:35 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
So it blows cold air all the time?
Do you hear the compressor clutch engage and disengage? (Clicking sound and engine rpm pulls down and then recovers)
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svocal
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Report this Post10-06-2019 07:58 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Update....
After reconnecting and disconnecting the relays a few times.... The AC no longer blows cold air.
However as soon as I turn the ignition key in the "on position" but with the engine off....i hear a motor sound(underneath the dash or in the front hood compartment) kick in. It stays on and i can feel air passing thru and under the dash. I check the front compartment and see that the radiator fan is on, but what else could be blowing the air?



 
quote
Originally posted by olejoedad:

So it blows cold air all the time?
Do you hear the compressor clutch engage and disengage? (Clicking sound and engine rpm pulls down and then recovers)


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Patrick
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Report this Post10-06-2019 08:49 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by svocal:

...as soon as I turn the ignition key in the "on position" but with the engine off....i hear a motor sound(underneath the dash or in the front hood compartment) kick in. It stays on and i can feel air passing thru and under the dash. I check the front compartment and see that the radiator fan is on, but what else could be blowing the air?


There's a blower of course for the heater and A/C... but as long as the OFF button has been pushed in all the way, there should be no fan blowing anywhere. (The rad fan should only turn on if the coolant temp has reached 235°F.)

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svocal
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Report this Post10-06-2019 09:19 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
The OFF button is pushed in all the way. Motor still kicks in.
How do I disconnect the blower motor?

 
quote
Originally posted by Patrick:

There's a blower of course for the heater and A/C... but as long as the OFF button has been pushed in all the way, there should be no fan blowing anywhere. (The rad fan should only turn on if the coolant temp has reached 235°F.)



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Patrick
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Report this Post10-06-2019 09:40 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by svocal:

How do I disconnect the blower motor?


Open the hood... and you're looking right at the blower!

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svocal
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Report this Post10-06-2019 11:54 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Issue resolved.
Thanks to olejoedad and patrick for the suggestions.
Found that the radiator fan and poorly insulated cabin was the culprit. The radiator fan was blowing air into the cabin.
I disconnected the radiator fan to find the issue.
However....I do hear a low fan noise in the engine compartment when the key is on but engine is off.
Amy ideas?
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Patrick
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Report this Post10-07-2019 12:19 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by svocal:

I disconnected the radiator fan to find the issue.
However....I do hear a low fan noise in the engine compartment when the key is on but engine is off.


This is why it's helpful to supply a few details about your Fiero. Yes, it's an '87... but what engine does it have? I'll have to assume it's a 2.8 V6... in which case you must be hearing the trunk blower. It's on the same circuit as your rad fan. You'll need to determine why that circuit is live when the engine is cold. Detach the single wire from the fan switch on the engine and see if the trunk blower stops.
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msweldon
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Report this Post10-07-2019 02:19 PM Click Here to See the Profile for msweldonClick Here to Email msweldonSend a Private Message to msweldonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

This is why it's helpful to supply a few details about your Fiero. Yes, it's an '87... but what engine does it have? I'll have to assume it's a 2.8 V6... in which case you must be hearing the trunk blower. It's on the same circuit as your rad fan. You'll need to determine why that circuit is live when the engine is cold. Detach the single wire from the fan switch on the engine and see if the trunk blower stops.


Patrick, correct me if I'm wrong but 87 2.8's did not have a blower fan in the trunk, only the 86, and maybe prior. My 87 GT did not have a blower fan but the 86 GT did..

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Patrick
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Report this Post10-07-2019 02:31 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by msweldon:

Patrick, correct me if I'm wrong...


Okay... you're wrong.

88's were the only year that 2.8 Fieros didn't come from the factory with a trunk blower.

 
quote
Originally posted by msweldon:

My 87 GT did not have a blower fan...


If it was indeed an '87 with a 2.8, then either the trunk blower (and associated ductwork) was removed... or your GT started life as a 4-banger.

[This message has been edited by Patrick (edited 10-07-2019).]

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David Hambleton
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Report this Post10-07-2019 10:13 PM Click Here to See the Profile for David HambletonClick Here to Email David HambletonSend a Private Message to David HambletonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by svocal:
The radiator fan was blowing air into the cabin.

I'm confused. How could that happen? The front trunk is in the way.

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svocal
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Report this Post10-07-2019 11:41 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Apparently the trunk as modified which explained a few items.

 
quote
Originally posted by David Hambleton:

I'm confused. How could that happen? The front trunk is in the way.


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msweldon
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Report this Post10-08-2019 08:25 PM Click Here to See the Profile for msweldonClick Here to Email msweldonSend a Private Message to msweldonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Patrick,

I stand corrected... I pulled the engine, front crossmember, and refreshed entire suspension on my old 87GT and never pulled back the trunk carpet to notice the fan... Just looked up the fan...87 2.8's had them indeed....
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Patrick
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Report this Post10-08-2019 08:33 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by msweldon:

...never pulled back the trunk carpet to notice the fan


Okay... but you never noticed the blower tubes?

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Report this Post10-09-2019 12:09 PM Click Here to See the Profile for da.slyboyClick Here to Email da.slyboySend a Private Message to da.slyboyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by svocal:


Found that the radiator fan and poorly insulated cabin was the culprit. The radiator fan was blowing air into the cabin.
I disconnected the radiator fan to find the issue.



I think it would be interesting to post of picture of your front trunk area as I'm really confused on how the rad fan was blowing a very noticeable amount of cold air into the main cabin. Also wouldn't it start being warm air when the engine got to temp?

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TXGOOD
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Report this Post10-09-2019 02:33 PM Click Here to See the Profile for TXGOODClick Here to visit TXGOOD's HomePageSend a Private Message to TXGOODEdit/Delete MessageReply w/QuoteDirect Link to This Post
As far as your radiator fan turning on with the ignition that will happen if someone
installed new switches on the AC compressor and grounded them, which is what the instructions tell you to do.
I forgot, the last time I installed new switches and now my fan is on all of the time with the ignition on.
I need to clip the ground wires going to them.
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svocal
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Report this Post10-09-2019 11:55 PM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks for the info. I personally prefer to always have the fan on.


 
quote
Originally posted by TXGOOD:

As far as your radiator fan turning on with the ignition that will happen if someone
installed new switches on the AC compressor and grounded them, which is what the instructions tell you to do.
I forgot, the last time I installed new switches and now my fan is on all of the time with the ignition on.
I need to clip the ground wires going to them.


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svocal
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Report this Post10-10-2019 12:06 AM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
The previous owner did some modification to the trunk area when building the replica. Note sure how to upload pics on this forum?

 
quote
Originally posted by da.slyboy:


I think it would be interesting to post of picture of your front trunk area as I'm really confused on how the rad fan was blowing a very noticeable amount of cold air into the main cabin. Also wouldn't it start being warm air when the engine got to temp?


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Patrick
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Report this Post10-10-2019 03:20 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by svocal:

Note sure how to upload pics on this forum?


If you're running a Windows PC, download and install PIP to host and post images here. Max width - 1024 pixels. Max file size - 300 kb.
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svocal
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Report this Post10-11-2019 05:57 AM Click Here to See the Profile for svocalClick Here to Email svocalSend a Private Message to svocalEdit/Delete MessageReply w/QuoteDirect Link to This Post
Here is the pic of the trunk area. As i mentioned the previous owner made some modifications to it.



 
quote
Originally posted by svocal:

The previous owner did some modification to the trunk area when building the replica. Note sure how to upload pics on this forum?



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