Cooling fan controller trouble shooting questions.
#16
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Bob:
I finally drove the car all day Sunday, into town a couple of times, then to the Richmond area for dinner. The air temp was HOT, 97 F or so, felt like 110 F with the humidity. The darn A/C, cooling fans and fog lights worked all day, without ANY hitches. This thing is really tempermental. I thought for sure I'd get the thing to not work at some point in the day!
So I've got the spare relay and tools ready to replace relay X when the problem resurfaces, to see if the problem goes away. I'll follow-up when that happens. Thanks again for your input.
I finally drove the car all day Sunday, into town a couple of times, then to the Richmond area for dinner. The air temp was HOT, 97 F or so, felt like 110 F with the humidity. The darn A/C, cooling fans and fog lights worked all day, without ANY hitches. This thing is really tempermental. I thought for sure I'd get the thing to not work at some point in the day!
So I've got the spare relay and tools ready to replace relay X when the problem resurfaces, to see if the problem goes away. I'll follow-up when that happens. Thanks again for your input.
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I replaced Relay X this past week after the cooling fans, A/C and fog lights finally decided to not work when I had the tools and a replacement relay in the car. Just a couple of tugs and pulls to replace the relay and the problem is solved. In fact, before I pulled the old relay, I just pushed it in with a thumb and the cooling fans and A/C started right up with the key in the On position.
Drove it all weekend with no problems.
Dr. Bob, thanks a lot for the online diagnosis. Great work.
Drove it all weekend with no problems.
Dr. Bob, thanks a lot for the online diagnosis. Great work.
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Hey Bill--
Glad it all worked out!
Glad it all worked out!
#20
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Harvey,
Are you testing the AC function with the fog lights on and the fans running? Doesn't really test anything when it's cold outside. Are you chasing something?
Are you testing the AC function with the fog lights on and the fans running? Doesn't really test anything when it's cold outside. Are you chasing something?
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Plus the stuff you posted some years ago still holds true for those asking the same questions today. It's worth a repost. It's spring.
Harvey
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Just looked at the original posting dates and times. It took me over a day to come up with the answer about the X relay. I wish all the gremlins were that easy to find.
In my pile of 928 things I've accumulated, I have a fan/flap controller that came from a Bill Sanders' parts car a few years ago. He generously supplied some harness sections with it, along with the amplifier module from the front apron. My Big Plan for them was (and still is...) to add some diagnostic LED's to them so you can get a good indication of what the controller is asking and what the fans are actually doing. They are still sitting in the que, waiting for that elusive round twoit to show up.
One of the additoinal mods on the list is a way to fool the fan controller about the coolant temp, so a car with a lower-temp thermostat could actually be coaxed into running at that temp when it's depending more on the fans for temp control. The mod would involve adding a resistor in the radiator temp sender loop where it connects with the controller under the cover by the pass seat. Alternatively, I could mod the controllers and swap them with owners, and even make the trigger temps adjustable with a screwdriver. Downside with 'adjustable' is that most owners would try to make that temperature control deadband too tight, causing the fans to run constantly trying to cool the engine while the thermostat tries to get the engine warm enough. Uses too much power, wears out the fan motors in a hurry. Engine management richens the mixture slightly too. The gauge is steadier and lower though, at least until heat loading exceeds heat dissipation.
In my pile of 928 things I've accumulated, I have a fan/flap controller that came from a Bill Sanders' parts car a few years ago. He generously supplied some harness sections with it, along with the amplifier module from the front apron. My Big Plan for them was (and still is...) to add some diagnostic LED's to them so you can get a good indication of what the controller is asking and what the fans are actually doing. They are still sitting in the que, waiting for that elusive round twoit to show up.
One of the additoinal mods on the list is a way to fool the fan controller about the coolant temp, so a car with a lower-temp thermostat could actually be coaxed into running at that temp when it's depending more on the fans for temp control. The mod would involve adding a resistor in the radiator temp sender loop where it connects with the controller under the cover by the pass seat. Alternatively, I could mod the controllers and swap them with owners, and even make the trigger temps adjustable with a screwdriver. Downside with 'adjustable' is that most owners would try to make that temperature control deadband too tight, causing the fans to run constantly trying to cool the engine while the thermostat tries to get the engine warm enough. Uses too much power, wears out the fan motors in a hurry. Engine management richens the mixture slightly too. The gauge is steadier and lower though, at least until heat loading exceeds heat dissipation.