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Engine compartment cooling fan questions by john-t-b
Started on: 02-12-2018 01:34 PM
Replies: 14 (469 views)
Last post by: Blacktree on 02-13-2018 10:22 PM
john-t-b
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Report this Post02-12-2018 01:34 PM Click Here to See the Profile for john-t-bSend a Private Message to john-t-bEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have an 86 GT all stock (as far as I know).
So previously while driving my son to the DR i had to jump out the radiator fan and this cooling fan. I ended up just using a toggle switch. I don't have a lot of time to work on the car and it's really just a toy for me. It's actually my first personal car since being married with kids in about 22 years.

I have done a search but still have some questions about the engine cooling fan. The one that is ducted to the coil and the alternator.

Is this a 2 speed fan? If so what/how does it determine which speed to run?
How would I start to track done what is keeping these fans off? I changed the temp switch in the engine but did not make any difference. * I am making he assumption that the one I got was correct from the auto parts store.

I also am planning on adding small radiator cooling fans to the engine compartment to further help. I just want to make sure it looks good when I am done.

I appreciate the help.
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olejoedad
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Report this Post02-12-2018 02:15 PM Click Here to See the Profile for olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
The trunk mounted cooling fan is single speed, and comes on when....
1. The radiator cooling fan comes on (triggered by the fan switch on the engine)
2. The HVAC control is set to any A/C setting or the DEFROST setting.


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Blacktree
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Report this Post02-12-2018 02:54 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
^^ The above is correct. The radiator fan and engine blower each have their own relay, but the relays are wired in parallel. So both relays are activated simultaneously. The fan switch on the engine or the A/C control head can activate them.

How exactly did you wire in your bypass switch? Does it ground out a green/white wire? Or are you sending battery power to the fan?

Anyway, first thing to do would be to check the 'ELEC/FAN' fuse. It's a 20 Amp fuse in the upper right corner of the fusebox. That fuse powers the relays for both the radiator fan and engine blower. If the fuse is good, move on to the relays. The radiator fan relay is next to the driver side headlight assembly. I can't remember where the engine blower relay is. (maybe somebody will help)

[This message has been edited by Blacktree (edited 02-12-2018).]

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john-t-b
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Report this Post02-12-2018 04:00 PM Click Here to See the Profile for john-t-bSend a Private Message to john-t-bEdit/Delete MessageReply w/QuoteDirect Link to This Post
The relay is right next to the bllwer in the rear.

I jumped 2 of the 3 brown wires so anytime the key is on the blower in the engine compartment is on.
The radiator fan I used a toggle between the black and red on the far ends of the relay. ** At least it appears to be black ** That's another thing that bothers me because on the wiring diagram in the Haynes book black is ground and red is live.
I did this about 2 years ago on the fly just trying to get home from my kids DR appointment.

The 20 amp fuse appears good but I didn't ohm it out. It's raining again so it'll have to wait again.
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Blacktree
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Report this Post02-12-2018 04:23 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Got it. That green/white wire I was talking about is the activation wire for both relays (radiator fan and engine blower). If you ground that wire to the chassis or engine block, it should activate both relays and kick on the fans. If not, then chances are that fuse is bad or both relays are bad.
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john-t-b
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Report this Post02-12-2018 04:36 PM Click Here to See the Profile for john-t-bSend a Private Message to john-t-bEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Blacktree:

Got it. That green/white wire I was talking about is the activation wire for both relays (radiator fan and engine blower). If you ground that wire to the chassis or engine block, it should activate both relays and kick on the fans. If not, then chances are that fuse is bad or both relays are bad.


Good to know thank you.
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john-t-b
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Report this Post02-12-2018 05:21 PM Click Here to See the Profile for john-t-bSend a Private Message to john-t-bEdit/Delete MessageReply w/QuoteDirect Link to This Post

john-t-b

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Well I just put everything back like it should be and shorted the green and white to the chassis.

Both fans worked. So looks like either the temp switch is bad/wrong or I have to trace back some wiring.

Most likely it's a wiring problem with my luck... I did try jumping the switch and nothing happened so....the journey continues.
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Blacktree
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Report this Post02-12-2018 05:28 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Another thing you can try is turn on the A/C. Since the fans and relays work, that should activate them. Even if the A/C doesn't work, all that's needed is for you to hit the button on the control panel.

If the A/C kicks on the fans, then you probably have a bad fan switch.
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USMUCL
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Report this Post02-12-2018 05:35 PM Click Here to See the Profile for USMUCLSend a Private Message to USMUCLEdit/Delete MessageReply w/QuoteDirect Link to This Post
OP, not to insult your intelligence, but are you sure the fan is not running?

I have seen it where the fan was not blowing any air out near the coil or alternator. Turned out, the fan WAS running . . . but some mice had built a nest in the piping that was blocking all air flow.
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john-t-b
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Report this Post02-12-2018 06:00 PM Click Here to See the Profile for john-t-bSend a Private Message to john-t-bEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by USMUCL:
OP, not to insult your intelligence, but are you sure the fan is not running?
.


DID YOU JUST CALL ME INTELLIGENT?

I made sure of it put a peice of paper between the fan outlet and coil and blew like crazy. Then the same for the alternator.

But thank you.
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liv4God
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Report this Post02-13-2018 05:31 AM Click Here to See the Profile for liv4GodSend a Private Message to liv4GodEdit/Delete MessageReply w/QuoteDirect Link to This Post
Another, probably less likely possibility is a loose fuse connection. My Fiero had the same problem, no fan coming on. I put in a new fan switch thinking that was the problem, but it still didn't work. Fuse was good, relays good, so I was lost. Then realized the fuse was quite loose in its socket. Used some needle nose pliers to push the terminals closer slightly. Put the fuse back in and voila, it worked.

[This message has been edited by liv4God (edited 02-13-2018).]

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olejoedad
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Report this Post02-13-2018 08:57 AM Click Here to See the Profile for olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
The fan switch activates at 235°F...

It could be that your temp gage is reading high and the water temp isn't high enough to close the thermoswitch.
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2.5
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Report this Post02-13-2018 09:43 AM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by john-t-b:

I also am planning on adding small radiator cooling fans to the engine compartment to further help. I just want to make sure it looks good when I am done.

I appreciate the help.


Just some thoughts.

A stock Fiero really doesn't need extra engine bay cooling. If you do add more fans make sure you have enough alternator power to keep up.

[This message has been edited by 2.5 (edited 02-13-2018).]

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john-t-b
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Report this Post02-13-2018 08:32 PM Click Here to See the Profile for john-t-bSend a Private Message to john-t-bEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks to all. Lots of good info, suggestions and tips. I don't post all that much because I search and usually find answers to my questions. Although it's good to know that you are all willing to help.

I just finished putting in another new coolant temp switch and this one works. Just let the run for a while and let it cycle on and off at least 3 to 4 times.
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Blacktree
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Report this Post02-13-2018 10:22 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Congrats.
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