Topic: Radiator Cooling Fans
in Forum: C4 Cooling and Heating Systems
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I have a 1992 C4 Corvette. One fan comes on at 227 degrees and goes off at 217 degrees. Same fan comes on when the A/C is turned on. Other fan does not come on and it is a new fan. I have checked the relay and it is good. When is this fan supposed to come on: at what temperature and when? Is there an inline fuse for the fan, because I cannot find one. Where would it be?
I also unhooked the fan that works and let the motor get to 230 degrees and the new fan never came on. At that point I just turned it off! Even with this problem resolved I would like to know how to get the temperature to run 200 degrees or cooler.
Any ideas of what is going on?
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Your primary fan temp is correct ( I think the spec is 225* on temp)......the secondary fan on temp is 232-233* and off at 225*
96LT1 2010-07-01 17:57:41
I gave a quick answer before (my bad)---i'll try to answer your questions now--the primary and secondary fan relays don't have a fuse--they both use fusible links-- try this -remove the secondary fan relay---find the terminal with the red wire--check with a test light or VOM it should be hot all the time-if it's not fusible link may be bad. If you have voltage then jumper the red wire terminal to the pink and black wire terminal (this is the power for the secondary fan ) the fan should run assuming the fan ground wire is good. If the fan runs at this point--then it's likely not getting hot enough for the ECM to turn on the secondary fan. If you want cooler operating temps the solution will be to have the ECM reprogrammed to run the fans "earlier" at lower temps. Also you may or may not know--as i and other members have said before be sure the radiator is clean inside and outside---airflow and clean radiator fins are very important. Hope this helps 
Vaughn
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Vette(s): 1985 Coupe-L98/Auto,Bright Red/Carmine.
1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.
Yep...the pusher/secondary fan will only come on at 230+ temps, but it should also come on at a lower temp with the A/C on, depending on the pressure switch operation for the A/C, and if the PCM commands it. The pusher on my '85 will come on at idle, with the A/C on, if the high side of the A/C gets up there due to engine temps in the 225 range.
230deg on these engines is not "too hot", even tho that goes against everything we learned in the old days. These engines were designed/engineered to run with elevated engine temps...which is the main reason they started specifying Mobil 1 oil. Running one too cool will actually cause more wear on it.
230deg on these engines is not "too hot", even tho that goes against everything we learned in the old days. These engines were designed/engineered to run with elevated engine temps...which is the main reason they started specifying Mobil 1 oil. Running one too cool will actually cause more wear on it.
Joel Adams 
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
These fans do come on at a high temp - and that is what GM wanted for a variety of reasons. But, Mid-America Motorworks does sell a kit that lets you switch on the fans manually. I have it on mine for when I am in hot summer traffic, and it brings the temperatures down nicely.
There is no problem a little horsepower can't fix!
C4s: 1993 LT-1 coupe, 6-Speed, White w/black
1986 L-98 Coupe, 4+3 Trans, Satin Black w/red-black interior - SCCA Time Trial racecar.
C3: 1979 L-48 couple, auto, Red w/doeskin interior.
To Vaughn,
I just joined and am having trouble replying to those who have answered me. I wanted to thank you for your information. I installed toggle switch under my spoiler and will turn it on mannually each day. I also thank you for telling me about dirt between the radiator and condenser coil. There is dirt, it looks difficult to clean out. Any suggestions on how to get to this area??? Another great piece of advise is programming the EMC....where is this located?? Do I need to take it out?? This seems to be a good idea. I do not like it running so hot. This is a great site and I am thankful for all the advise. Parts house says I have a 180 degree thermostat but I believe it's got a 195 in it. I would like to change it when I have the EMC programmed, would like it to run 180 or so. One of the reasons I am wanting to cool the car down is I have a front main that leaks and it doesn't seem to leak at cooler temperatures.
So glad I found this site. You guys have been very helpful and it is much appreciated........Ty
Thanks Joel for the advise. I appreciate all your help. Hope to keep in touch. Just joined this forum and I am glad I found it. ......Ty
Your best bet on cleaning the radiator would be to remove it and use a garden hose to clean out the crud in the cooling fins---maybe using a cleaner such as "Mean Green" to help loosen the dirt. Don't Scrub or clean the fins by hand or use a pressure washer (some are strong enough to do damage)---this will also give you a chance to clean the AC condenser fins in the same way while it remains in the car.
96LT1 2010-07-10 07:55:03
The OEM thermostat for all LT1s was 180*--they are also made/shaped different then other small block chevy thermostats --they were designed for the LT1 reverse flow cooling system and ONLY the LT1.
The ECM--- assuming all LT1s are the same (i'm not positive) should be under the hood/left side close to the firewall and above the battery. It would need to be removed and sent to one of the many online companies and reprogramed to run the fans at a lower temperature. One company popular w/Vette owners is "pcmforless"--but there are many more online. On the later C4s ( i think 95 & 96s) buying a handheld programmer would be a option, but as far as I know-- no one offers one for your '92. hope this helps.
Vaughn
PS--- didn't mention it (likely goes without saying)---but reprogramming the ECM would elimanate the need for the fan "toggle switch"
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Vette(s): 1985 Coupe-L98/Auto,Bright Red/Carmine.
1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.
[QUOTE=tyharrison]I just joined and am having trouble replying to those who have answered me. [/QUOTE]
What sort of problems are you having, as far as replying/posting? Please P/M me if you are still having trouble.
What sort of problems are you having, as far as replying/posting? Please P/M me if you are still having trouble.
Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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lanoka harbor, NJ - USA
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Vette(s): 1990 L-98 white/ red/black leather interior targa top auto
1975 L48 blue/black leather interior t tops auto
as far as reprogramming the ecm on my 90 it has a prom in it and you can have a chip made that goes in between the prom and the ecm with all the changes on it. this way you can use the car until the chip arrives and then just install it and if you ever want to go backto the original settings you just have to remove it.don't know if it's the same on newer models.
the dynamic duo
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Vette(s): Early production C4 Corvette Coupe ( 02-20-1983 is the production start date )
I have a 84 C4 with CFI the fan will not come on @ any temp and it will heat up unlet i turn on the fan manually i now have it connected to a swith under the dash and i cant rely on the engine turning it on, so i will turn it on at start-up sometimes i dont need to since im moving at highway speed ( 70mph ) and it is steady temp of 207 degrees I have a new relay and a new temp switch it still wont turn itself on-------- is there a way to mount a fan in the front somewhere one out of a savage lot car ? one that I can switch on as a pucher fan for in town driving and not have to worry about the main fan turning on ? what else can I check for this ? it wont come on at temperature ( which is ??? 234* ? ? ? ??
Need some help on this anyone in the omaha area ? ?? ? come by and help me fix it ?
in Forum: C4 Cooling and Heating Systems
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