Dual fan hack question. Help!
07-23-2018, 01:50 AM
#16
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07-23-2018, 09:30 AM
#17
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07-23-2018, 10:32 AM
#18
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Join Date: Feb 2018
Location: Knoxville, TN
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FYI for those who think they're running cool --The stock gauge is garbage. The middle of '0' in 180 is actually about 210 per Durametric/OBD.
Your purge valve should be manually actuated, i.e. it shouldn't be in the up position unless you moved the wire clip to set it there. The airlift tool is an awesome thing to have to refill your coolant and also to check that it is holding adequate pressure.
Basic blocking and tackling:
Make sure the coolant is full/bled and no more than a 50/50 mix.
Verify the system is holding pressure.
Validate the fan system is operating right. If it's only working on high it could be a bad low speed resistor. They're low to the ground and susceptible to damage and corrosion on these cars.
Your purge valve should be manually actuated, i.e. it shouldn't be in the up position unless you moved the wire clip to set it there. The airlift tool is an awesome thing to have to refill your coolant and also to check that it is holding adequate pressure.
Basic blocking and tackling:
Make sure the coolant is full/bled and no more than a 50/50 mix.
Verify the system is holding pressure.
Validate the fan system is operating right. If it's only working on high it could be a bad low speed resistor. They're low to the ground and susceptible to damage and corrosion on these cars.
07-23-2018, 11:00 AM
#19
Burning Brakes
Coming from a mostly mechanical background in wrenching I have almost no knowledge in wiring. That being said my coolant temps are hitting a hot 225F in stop and go traffic. After cleaning out the front rads, 160F thermostat, new water pump and switching to a new coolant reservoir cap I was hoping this would fix the problem at least a little bit, it didn't really do anything. Now I've come to the conclusion that I need to install a switch to control the fans since they have a mind of their own. I've looked at a couple how to's and know where the #20 and #22 relay's are, I just want to know how to run a wire to them while keeping the stock function of the fans turning on by themselves. Where do I connect this wire and HOW do I connect it. Pictures would be a god send...
Help this noob out!
Help this noob out!
One - someone took the relay out with a piece of 18 gauge wire - stripped it and put it in the correct socket (85 if I remember - but definitely verify) and simply put the relay back in... this kind of wedged the wire in there. That's the ground side of the relay BTW.
The other was to pull the relay holder out entirely and just tap into the wire from the bottom side.
Honestly, I think I am just going to go the 'wedge it in there' route. I'll run the wires so there is no tension and no risk of it being pulled. Besides - if it comes out - it's just a ground jump. It just means that the switch won't work (but the automatic function stays the same)
Last edited by Blue Chip; 07-23-2018 at 04:43 PM.
07-23-2018, 01:35 PM
#20
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07-23-2018, 02:08 PM
#21
Rennlist Member
Such a shame we cannot rely on these gauges. What’s the point of them if they aren’t accurate? Are we just supposed to be happy if they are precise?
07-23-2018, 02:18 PM
#22
It's pretty likely the power resistors for your fans are damaged. The same fans run for both the low speed and high speed. A resistor is in series with the fan on the low speed setting, so the fan sees a lower voltage and spins slower. On the high speed setting, it sees the full 12V and spins full speed. If that resistor is blown on either fan, then it won't see ANY voltage on the low speed setting, and won't work until the car gets hot enough to trigger the high speed. This could be the issue that's letting your car get pretty hot before any fans come on; it may be trying to turn on the low speed, but the fan doesn't respond and the computer doesn't know that. The resistors are relatively exposed in front of the front wheels and can get splashed with water, exposed to hot and cold, etc. and have a tendency to fail. They're pretty easy to replace and it's been covered on here and other sites before.
Before you go rewiring stuff and adding switches to trigger the fans on demand, I would fix the above to make sure all the baseline functions are working. If you have durametric you can trigger both low and high fan settings on demand to confirm what is working and what isn't. If you don't have that, you can jumper the relays to do the same test.
Before you go rewiring stuff and adding switches to trigger the fans on demand, I would fix the above to make sure all the baseline functions are working. If you have durametric you can trigger both low and high fan settings on demand to confirm what is working and what isn't. If you don't have that, you can jumper the relays to do the same test.
07-23-2018, 02:21 PM
#23
Rennlist Member
^^ Dumb question, but if the low speed fans come on when the OP turns on the AC, are those resistors being used in the same fashion?
07-23-2018, 02:25 PM
#24
Probably but the sound can be misleading. For instance on my car the passenger side resistor was burned, so without carefully checking, one might hear the driver's side fan running and think everything is fine, but they'd only be getting 1/2 the desired airflow.
07-23-2018, 02:36 PM
#25
Rennlist Member
Agree. You can feel the air even at low speed. High speed is REALLY obvious.
07-23-2018, 03:26 PM
#26
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07-23-2018, 04:02 PM
#27
Instructor
07-23-2018, 06:09 PM
#28
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Thread Starter
Yeah, both my low speeds are working. Sometimes one is running and the other one isn't though? This has always confused me, it's done that ever since I bought it a year and a half ago. Does this still sound like a relay issue?
07-23-2018, 06:12 PM
#29
Yeah something is wrong then. Either shaky wiring, resistors, relays, or the fans themselves. The left and right fans should always be doing the same thing. There are no conditions when one should be running and the other is off, so you need to track down what's up with that first before monkeying with adding features.