hi all, i now have a 90 745 and i have read the 700-900 faq on the a.c. system.
i am farmiliar with the expansion type system the old 240s use and other older vehicles but not with the orifice tube cycling system.
A.C not blowing cold at all. i wanted to add some freon i hooked up to the low side only, 90 degrees ambient temp and 90 % humidity. as the high side doesnt have the r-134 adapter. with car idleing i add about a half of can which brought the low side from 35 to 50 pounds, and the compressor is not cycling but is engaged. and i dont want to go above 50 psi on low side because im not sure how this system works (just in theory from FAQ).
if i rev motor at 3,000 rpms the low pressure will drop and cylce between 20 and 40 psi.
took her for a spin and its blowing 68 degrees. i figure i better stop until i learn more about the orifice tube system.
any advice would be great.
p.s. i just took another look and there is a high side adapter on compressor i didnt see earlier so this should help me tomorrow.
but still not sure exactly what im looking for on this type of system.
i have done 4 or 5 r-134 conversions on the 240 with great results.
thanks for any help.