I have an 88 Firebird, and I'm wiring a fan with a toggle switch. (No therm)

Here's the relay setup I've been directed to use.

30 - Constant 12v from battery to Relay
85 - Hot-in-run source
86 - relay to toggle switch, toggle switch to ground
87 - relay out to fan
87a - not used

I'd like to double check that this is a correct setup, and if so, I'm really new to automotive wiring and would like to know where exactly I need to wire to for my constant 12v source and the hot-in-run source.

 

In your fuse panel, you'll see a single slot marked IGN - it won't hold a fuse because a fuse has two "legs" and this is a single slot with nothing in it. Use a standard 1/4inch male spade connector on a 18 guage wire, plug it in that slot, run the wire to your toggle switch and add a 1/4 female spade connector to connect to the toggle.

IF the toggle is not illuminated, skip this .... use another 18 guage wire, crimpa ring terminal on the end, and attach it under the dash anywhere there is a metal screw going into metal - put ring connector under that screw. On other end, crimp on a female 1/4inch female spade connector and attach to neg term on the toggle switch.

On another 18guage wire, crimp a female 1/4 inch spade connector, and connect to last toggle terminal - run this wire out through firewall to your fan relay, crimp female 1/4 inch spade connector on the end, and connect to terminal 85 of the relay.

On another 18guage wire, crimp a 1/4iinch female spade connector, and connect to relay 86 - other end crimp on a ring terminal and place under any metal screw into metal under hood.

On a 10 guage wire, crimp a larger ring terminal on one end and connect to power distribution block (where all the red wires run to) between battery and radiator (down low, you'll see it there). On other end of that wire, crimp a 1/4inch female spade connector and connect to relay 30.

Using a 10 guage butt connector, crimp the fan positive wire (black with red stripe) together with another 10 guage wire to extend it to your relay. On the other end, crimp a 1/4inch female spade connector, and connect to relay 87.

Lastly, your fan should already be grounded on it's neg wire - but if not, then crimp a ring terminal on the end of the fan neg wire (solid black wire) and attach to any metal screw going into metal under hood.

Done.

Key on, IGN gets 12v+, which goes to toggle. Toggle is grounded (if illuminated), and so whn toggle flipped to ON, then the toggle lights up, and 12v+ sent to relay 85. Relay is grounded on 86, and thus relay activates, switching the 12v+ from battery (relay 30) over from 87a (not used) to 87 (your fan, which is grounded), and thus the circuit is complete.

 

If your stock relay wiring is still intact you can simply tap into the DK GRN/WHT wire from the relay and run that to the toggle switch and ground

IMHO, Id replace the thermal switch and use the switch as an emergency override

 

Good info

 

thats what i did if i understand correctly, i still have the stock switch to make it come on but i tapped into it with my grounded switch to lower the temp when desired

 

Thats correct

I prefer the manual override switch as a fail safe because Ive had a good many of the thermal switches fail in the middle of traffic

 

I have an 86 Iroc z28 and I have to plug the fan in from under the hood in the top left corner everytime I wanna use it.does anyone know how I can fix this?

 

Figure out where its rigged/shorted and mend it