i don't know if referring to full-size blazer or the S10 blazer, but in either case.... looks like the same diagram used between a 4.3 blazer S10 and a 5.7 full-size S10.

can probably ignore the TH400 section.

brake switch is wired in series with the TCC solenoid, so brake application should always disable TCC, otherwise some kind of trans issue exists and is keeping it engaged.

the way the temp and 4th gear switches are setup in the other diagram are kind of confusing, but maybe there is some reasoning behind it? not enough digital inputs available to watch them seperately?

http://imgur.com/f7drJku,4MzqsK8