2 apex safc's went out at the same time???

[frankies1390]

hey i'm still learning about the afc's... but the both went out at the same time! I have a 92 240sx with a KA-T in it with t3/t4 style set up and a 90 240sx with a red top sr... and on my 92 the afc reads backwards!!! all settings like the MAf or air flow reading goes down in percentage when i gas it along with it leaning out when settings shouyld be dumping fuel? which i've had 2 shops look at they say its "hooked up correctly". and with my 90 240sx with the sr my air flow just quit reading which has also been to the shop and tested and they traced the wires and said my MAF and TPS are reading and getting voltage so my question is, is there something hooked up wrong or are these known to go out? my 92 has the safc I blue screen orange buttons and silver casing and my 90 has the safc II black screen black casing??? just lookin for some help