89 A4-Both fans run continuously
Thread Starter
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
89 A4-Both fans run continuously
Wired in a manual fan switch from MAM. Its done properly, worked fine for awhile. Installed a Hypertech low temp fan switch (between #1 and 3 cyl.); system worked as it should, had full sontrol of switch when I wantedit. Fast forward a few months--Within a minute or two of starting cold, both fans come on and stay on. Flipping the switch does nothing. Something I'm missing here?
Thanks in advance!
Thanks in advance!
Pro
Joined: May 2002
Posts: 541
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From: Kalama WA
Originally Posted by cuisinartvette
Wired in a manual fan switch from MAM. Its done properly, worked fine for awhile. Installed a Hypertech low temp fan switch (between #1 and 3 cyl.); system worked as it should, had full sontrol of switch when I wantedit. Fast forward a few months--Within a minute or two of starting cold, both fans come on and stay on. Flipping the switch does nothing. Something I'm missing here?
Thanks in advance!
Thanks in advance!
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Where are the relays located and how do I test them? Have a multimeter, don't know what setting to use.
I'll call MAM and see what they can do about getting another. Like them coming on early and keeping it a little cooler.
I'll call MAM and see what they can do about getting another. Like them coming on early and keeping it a little cooler.
Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
The main fan relay is on the rear of the inner fender well, below the brake MC; the booster fan relay is on the LH rear of the radiator shroud.
Set the DMM on DC Volts, auto-range and check voltage on the Grn/Wht wire at each relay.
Also, disconnect the Gnd wire from your manual switch.
Check for any stored trouble codes. It's possible that the ECM is bringing on the main fan and that the aux fan switch is frozen closed.
The main thing is to be systematic with the diagnosis. This means to start by removing any common ties between the two relays.
Set the DMM on DC Volts, auto-range and check voltage on the Grn/Wht wire at each relay.
Also, disconnect the Gnd wire from your manual switch.
Check for any stored trouble codes. It's possible that the ECM is bringing on the main fan and that the aux fan switch is frozen closed.
The main thing is to be systematic with the diagnosis. This means to start by removing any common ties between the two relays.
Thread Starter
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
When I check relays am I turning key to "on" position and touching the probe to the green/white wire on the relay?
If the fan switch is bad, should the fan shut off if I pull the wire off it? GOing to check it in awhile.
If the fan switch is bad, should the fan shut off if I pull the wire off it? GOing to check it in awhile.
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Team Owner
Joined: Jan 2003
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From: Summerland B.C. Canada
Originally Posted by cuisinartvette
If the fan switch is bad, should the fan shut off if I pull the wire off it? GOing to check it in awhile.
If it takes a minute or two for the fans to come on it sounds like something more of an ecm control. Are your two relays linked together now ( because of the manual switch and MAM switch) ?? That would explain why both come on.
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by cuisinartvette
Fast forward a few months--Within a minute or two of starting cold, both fans come on and stay on. Flipping the switch does nothing. Something I'm missing here?
Thanks in advance!
Thanks in advance!
RACE ON!!!
Thread Starter
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Got it! After coming back from a long cruise this morning, i noticed a little smoke after I shut it off;looks like a poss. V.C. leak. As i looked around the base of the valve cover I found the problem-Plug for the AC was hanging-Somehow became disconnected. Hooked it back up and all seems to work like it should. I never would have figured, as i never use the AC.
Thanks for all the help. I'll keep your tips in mind should I have a future issue.
Thanks for all the help. I'll keep your tips in mind should I have a future issue.
