The resistance of each IACV "quarter" coil is nominally 22 ohms. After the coolant eats the insulation on the coil, the resistance drops to an ohm or two, or less. This overloads the ST509A transistor which is rated at 3A in steady mode or 6A in pulse mode.

Hello Max_5Gen,

following up on my post (#100 in https://maxima.org/forums/5th-genera...seconds-5.html ):

Re. inductance: Self inductance will increase the impedance of the circuit, resulting in lower current; consequently, lower-rated fuse should be required. Mutual inductance may generate voltage on one of the other coils. Without knowing details of the IACV wiring, and without knowing how the ECU pulses the four circuits, it's impossible to determine how.

I have tried to do worst-case analysis. In this context, self inductance is not a factor. Mutual inductance might be, but somehow I doubt it. (My experiment shows that the IACV works fine even when the maximal current is limited to 7.5 A).

Hope this makes sense. Thanks again for your comments,
--Maxiiiboy.

Hey Max_5gen,
Would you review this post and let me know if you have any suggestions?
Thanks,
Jason

http://forums.maxima.org/5th-generat...ml#post8381240

Hello Max_5gen, my System Entrance Control Unit has gone bad in my 01 maxima. I wanted to know if you know where I can order one? Or a jinkyard that ships? Thank you