i have a 93 Z28. I am not certain on whether my car should have one or two fans running. I know i have relays for a primary and secondary fans. I have posted a previous thread and received a response where, "The computer will command primary fan "ON" at 226º and "OFF" at 221º and secondary fan "ON" at 235º and "OFF" at 230º," (this response by SHOEBOX). if this is true then why is it that on my car the primary fan turns on at 240 degrees, and turns off at 220 degrees, and the secondary fan NEVER turns on??? as many of you know, 240 is in the red zone, and 220 is right before the red zone.

The problem seemed to have appeared after repairing the A.I.R. Pump, and removing MIL Code 26. Before the problem i believe the car still only ran one fan, but the fan turned on at 220 degrees, and turned off at 180 or 200 degrees. What happened??? Is it a relay or what??? Should both fans be working??? Is it the CPU??? I'm stuck and i really need help. HELP!!!

 

On my web site, there is an explanation on how the fans work. On 1993's and early 1994's, only the LH (primary) fan comes on initially. The RH (secondary) fan comes on at the higher temp. If you are using your temp gauge to tell when they come on, beware that it may not be totally accurate. If you are watching the temps with a scan tool, the temp sensor may not be accurate or your computer may have some different programming.

 

Alright. Thanks Shoebox. I'm going to go ahead and scan my PCM to check if maybe there is a problem with may fans. If there is i'll let you guys know, if not i'll still let you know.

 

i got my car's CPU scanned yesterday, and it revealed to me that my car's coolant temperature was 105 - 107 degrees. This was in direct contradiction with what was being shown on the temperature gauge on my dash. That gauge showed what i said before, between 220 and 240 degrees. The mechanic advised that i change out my thermostat, and the thermostat sensor. Is there a thermostat sensor??? Anyway, is what the mechanic advised correct, or whats going on?? Is my temperature gauge wrong, and if it is, how do i fix it??

 

No thermostat switch, just a coolant temp switch.

I'll bet anything the 100 degrees is in celcius.. that would explain why you see over 200 in the dash.


Alot of 93's including my own have this problem, for whatever reason if you turn the fans on cooler in the chip it usually come on, whereas they won't come on at the stock setting.

 

my 93's fans were PMSey too....so we just wired the primary to come on with the ignition, the car does not leave the 160* mark

 

Not a great way of doing things, keeps the car from warming up like it should and affects gas mileage

do the math, 25a 100% of the time or 25a 15% of the time

 

so you think we should have wired the secondary fan instead?..since it pushes less air

 

Seems like you may be right ROOSTER. I did the conversion and it just about comes out to exactly where my car is suggesting (105 degrees celsius = 221 degrees fahrenheit). So then what is the best thing i should do? Should i change my thermostat to a 160 degree model, and should i also change my coolant temp switch? Or what else can i do??

 

If you used free scan or something simular, the read out is in *C so its doing what you think it is.
If your capable of burning chips then lower the fan on temps to something like 82* C
there is a *C to *F converter on the net (lots actually) just google for it...

 

the secondary fan and the main fan are the same size, same motor, etc.. I don't know how you get that they are pushing less air.

The right way to be not wiring it all the time at all.


I would suggest trying a chip and 160 thermostat.

 

Thanks ROOSTER. i'll try the thermostat and get back to you on it as soon as possible. will i need a chip to help the thermostat operate properly, and if so, where can i find it. I looked at the Summit Catalog, and they only have things such as 1994 - 2002 Hypertech programmers, but not anything for a 1993. does that mean i don't need it, and that i can just drop in the 160 degree thermostat? Thanks

 

theres alot of people building chips out there for 93's..

I'm not allowed to say whose best, but do a search for speed density or 93 LT1 chips and you'll find them..

 

You can put in a 160 thermostat in without having any computer work done. It won't hurt anything. The thermostat does not rely on the computer for anything, just hot or cold coolant.
You don't see programmers for 1993s because you have to swap chips in them. The computers don't use flash programming like 1994 + do.

 

i switched the thermostat yesterday and found that the old one was in dire need of replacement. Lets just say the internals of the thermostat seemed to have popped out of place. I replaced it with a 160 degree thermo. the car does not get hot as fast as it used to, and the fans now seem to come on a little sooner too. From 240 degrees to now about 230. now i am on my way to switching the coolant temp. switch and i will be looking up those chips for my car.

Thank you all for your help, especially ROOSTER and SHOEBOX. I will get back to you on any advancements i make as i go through 'em.