So I have two relays (20 amp I think) for the fans... and NO directions for either!
They both have numbers written on the sides:

30 for the 12V in I am pretty sure
and that goes to a 87, which must be the power to the fan. Then it has a 85 (with a diode?) and 86... one must be ground and the other for the switched 12V.

One is better marked then the other (2 different brands). Actually the one that came with the temp sensor has wires from the harness, but it isn't clear which is for the ground and which is to the switched 12V source (black and grey wires). I assume black is for ground and grey w/white stripe is to the sensor/switched 12V... or is it the other way around? I don't want to use the sensor because it doesn't fit any of my ports in my manifold!



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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

This link tells you more than you want to know about relays. Down the page a bit the "Bosch" relay is dexcribed, using your 85, 86, 30, 87 terminology.
http://www.eatel.net/~amptech/elecdisc/relays.htm

 

Screw that last post, this one is much more concise!
http://www.the12volt.com/relays/relays.asp