First post, long time stalker! I recently picked up an 89 Z28 I believe to be a 305 TBI. It was sitting for a while but fired right up and made the 12 minute drive home. It suffers from the dreaded single electric fan not working unless the A/C is on!! I replaced the CTS and thermostat, can't get to the sender on the passenger head yet. I've decided to wire the fan to a toggle switch and came upon this mess. First, can I get opinions on how to repair it? And secondly, is there a diagram I can follow for the toggle switch? I've read through sooo many other topics like this but I think I got overwhelmed. Any opinions are appreciated!!!

 

Here is a coolant temp switch diagram from Austinthirdgen. Just run a wire from the black wire on the relay to your toggle switch then to a good ground. The switch and wiring will be protected by the fuse and will ground the relay to energize it just like the coolant temp switch would do. HTH!

 

Its not actually a 'problem' (with OE wiring) though, you do have a mess. TBI fans are only controlled by the fan switch (on at 238°F) or, by the hvac controls set to an a/c position (a/c does not need to work for fan to run)

 

Thank you! Fan is hooked up to a toggle switch for now. It will be done right eventually. I connected that green wire back together and the green/white back together. But the loose red one worries me. Do we happen to know what colors are supposed to be where??

 

This is for 92 tbi, 89 will be the same.