06-29-2022, 01:21 PM
(06-29-2022, 07:31 AM)Nachodaddy_imp Wrote: Max, just to verify, the resistors in post #1326 you identify as 220 ohm, and the ones you settled on in post # 1355 are 330ohm, right? And the ones I should install are the 330 Ohm? Or does it really matter?
Thanks again.
PS, I won't try this out until probably late September when the temperature in my garage drops below 90F (or 30C).
Completely understand Nacho, all in good time.
The resistance of one of the two windings of the iacv is around 100 ohms, the ecu checks this value constantly and if it decides the iacv has an open circuit it sets a code ( orange cel ) and puts the engine in " limp home mode" ; 5000 rpm limit.
So the ecu checks the current through the iacv windings, the minimum value resistor is 390 ohm before it sets an alarm, so any value resistor between 100 and 390 ohms is sufficient for the ecu to not set a code, the voltage across the windings is 12 volts according to my oscilloscope, so at 100 ohm the current flow is; 12:100=120 mA with a 50% duty cycle during iacv activation which is o,72 watts ( at 50% duty cycle ) for short periods of time.
So a 1 watt resistor of 100 ohm would work fine, but the same result can be achieved with a 390 ohm resistor, the power dissipation would now be; 12v x 0.03 A= .036 watts.
I tend to choose to do the job with minimal current draw but still reliable so i chose the 330 ohm resistors since they are also used to load the o2 sensor heater when unplugged, ( the ferret's o2 mod ) so it is a bit of a universal value.
So anything between 220 and 390 ohms will work equally well provided the power rating of the resistor is 1 watt, smaller than that means the reliability is compromised and the wire size of the resistor leads becomes too small to fit reliably in the connector,( 0.6 to 0,7 mm., too big a resistor would have larger wire diameters and be more difficult to insert into the connector and the connector's contacts would be splayed out too far in case it had to be re-connected to the iacv.
The 1 watt version i used fitted nicely into the connector if inserted 10 millimeters into the body of the connector, initially i did not insert them deep enough and the orange cel lit up so i re-inserted them a bit deeper at 10 mm.
Long story but now you know why .