help me figure out how to do it!!! I'm no electrical engineer!!

 

haaa.. u guys are funny..

 

Very nice!

 

Did a little test with a scan tool today. Car idling . 85 F ambient temp.

Found out that the fans kicks on once coolant temps reach 190 F degrees.

Fan blows for 10 sec. and shuts back off when temps hit 185 F.

 

I've got a Dynoflash, would Al supply this to his customers?

 

I'f it's a $5 part then $6 shipped thru USPS First Class Mail would be a good deal... Any word on that, Al?

 

Al cant sell it... it's a Buschur part. Not only that, but Bushcur won't sell it to us unless we have the bushcur flash..... workin' on making my own version.... (unless you decide to finally sell it buschur!!) I'll keep ya'll posted.

 

is this chip something that plugs in under the hood? or is t something that could be toggled inside the cabin.. like on the go just plug it in or flip a switch..

 

yes, that is my thought on it, I have found the corresponding voltage that the sensor reads when the coolant is at 180 degrees, now I just need to devise a way to knock 12 volts down to the correct voltage. (I'm really bad w/ electrical components)

 

All you have to do is call Buschur they sell it for $5

I tired making my own and failed miserably

 

AL: do you think I can get one up there on Sept17th? I don't think they will be selling/installing parts but maybe Buschur could put one aside for me? That way I could dyno with it in..

 

The correct way would be to get the car to normal operting temp and measure the resistance across the two terminals of the coolant sensor, then going ahead and finding an equivalent resistance at a electronics store.

 

Sounds to me like it's a thermistor in series with a resistor to either 12V or 5V. The other side of the thermistor is connected to ground. The sensor changes resistance with temperature. The change in resistance will cause a change in voltage where this voltage is feed to the ECU (V = I X R). With things like that typically there's a look-up chart or equation that correspond voltage to temperature. Find out what voltage you want and hook up a resistor across the sensor (thermistor) to force the voltage to always be below or over what you want.

The other way around would be to find out where in the calibration files (EEPROM location in ECU) this value is store and change that value (trip point).

 

Hah !... did more testing.

180 F degrees = 5.20 - 5.40 M ohms across the coolant temp sensor.

185 F = 4.60 - 4.80 M ohms

190 F = 4.20 - 4.60 M ohms

200 F = 3.60 - 3.80 M ohms

So if you jump the connector with a 5.2 M ohm resistor, The ECU will continuously read 180 F degrees.
Just went to Radioshack and I'll do more tests tommorow.

Note: This won't be advisable in the street for the ECU needs to see the actual reading of the temp sensor or it won't turn the fans on cause it won't ever see 190 F with the resistor on.

 

Are you trying to leave the fan always on or always off? Just curious but how are you measuring resistance with the power on? With power ON you should be measuring voltage not resistance. The resistance you're seeing appears to be very big much like you're measuring an open circuit.