another cooling fan problem

[blackvette89]

i recently changed my ecm and noticed that my fan (i only have one) only comes on at 236 degrees and off at 226. is this normal? it used to come on at 228. i changed the relay on the left wheel fender. I was going to replace the sensor to the right side of the block but noticed that the sensor i have has a blade type connector which is not what autozone has for the replacement. theres has a rounded type connector. any trouble shooting suggestions would be great! or maybe these temps are normal?

 

[Magmotor]

You can get the correct sensor at Corvette Central. The fan should come on at 226, stay on for 30 sec's and shut off if over 40mph or stay on if overheating is stll present. If the sensor totaly fails the fan will run continuiously. Is there a 14 or 15 code with the new ECM ? You might want to replace the thermostat to. Clean inbetween raidiators. Flush the system. More than likely it sounds like a temp sensor problem.

 

[blackvette89]

thanks for the info

i'll try a new sensor and let u know how it works out. thanks!

 

[caddy]

I have a 94 LT1 and I was wondering on that year model, short of spending a fortune on a reprogrammer from Hypertech is there anyway to make the fans come on earlier? Someone told me unless you have the A/C on they (the fans) don't come on until around 230 or so??
With the A/C off I would like them to come on earlier, are there any sensors I can buy or whatever, any help would be great.....


thanks

 

[Magmotor]

You can hard wire a switch to the fan relays and turn the fans on anytime you like. OR I was told that a guy named Jeff who is the C4 mods moderator on this site can custom program your chip to turn the fans on when ever....I'm sure there will be more input to this as many here have hard wired their fans to come on....stay tuned...!! They'll explain how to do it.....

 

[caddy]

I would love that, But I don't think the 94 model has a chip?

 

[Magmotor]

Welp, what i'll do then is keep my big mouth shut 'cause I don't know flip about a '94. Ya might want to do a 'Search' on this site for that type problem and year or post the question yourself. Lots of info on here for that, I'm sure. At any rate good luck with it....someone will help ya out......

 

[caddy]

Don't feel bad I don't know much about a 94' either, but I appreciate the help, anything you want to find out about corvettes this is the place to be..........these people here are smart!!! thanks for the help!

 

[WhalePirot]

do a 'Search'

Always great advice to search first!

I just bought a cooling fan switch from MidAmerica for 13 bucks, but my fan is thusly controlled. PN609-106 for '84-91, states an ON @ 200; OF @ 185. http://www.madvet.com/

The 1990 and later years also need a conversion harness.

Hayden makes fans with adjustable temperature switches (Pep Boys, summit, etc.). I think of these as nearly the last resort, after cleaning debris, down-adjusting switching temps and ensuring the cooling system is in good shape. I am not a fan (no pun) of the manual switch. I wired one as a temporary measure and treat it as an abnormal requirement; not routine modus operendi.

After I evaluate this newer switch, (yes, the connector is not flat) I will add more fans as necessary for this 406. It should not be required for either of us.

<Added later> The fan comes on at 192 and switches off at 180 or so. I need more time to fully evaluate this, but I think the 'running start' on the heat issue that the cooling fan gets, will much improve the cooling situation on this 550hp 406. Also, daytime will be a truer test, when OAT is higher.

From MidAmerica instruction sheet:
The fan switch is between cylinders 6 and 8 (passenger side) for 1984 and early '85 cars. After that any fan switch is between cyls 1 and 3.

The enclosed sheets do a fine job of describing where to install any switch you might purchase. I don't need the keyboard practice to echo it. Besides, I have found this the least expensive source for the PROPER switch.
Mike

 

[bradvette]

I just recently did the same thing as WhalePirot - got the low temp switch from Mid-Am + plus the harness since mine is a '90 which has dual fans. Coupled with a new lower temp t-stat (160 degree), all high temps are history. Both fans go on at the same time (rather than staggred at 228 & 238) at about 190-200 (hard to tell exactly with the guages in the '90). I can say this - the coolant and oil temp guages now don't go past the 1rst third portion of the guages. Since it runs much cooler, there's no strange heat-related sounds under the hood + its runs much better when warm. I'm totally pleased with this mod - its cheap, necessary IMHO for a healthier engine and other components under the hood.

 

[blackvette89]

thanks for the info, i'll let u know how i make out. since i only have 1 fan, i was told i have to unplug the sensor area on 1&3 and install there. the only bi*** is with the wiring!this is not my area of expertise!!