need help wiring 2 e-fans with relays
 

i need someone to tell me how to wire 2 e-fans with relays so i dont run them direct off of ign....... also will like to run my fuel pump with a relay if someone can help me with that to.

Add a toggle switch..when you purchase a fog lights relay, there is a wiring diagram in back of the package or the relay itself. Since ur running dual fan, im not sure if one relay is sufficient. you may need to run 2. as far as the on/off switch, 1 toggle switch should be able to handle.

same thing with the fuel pump, relay will provide direct + connection to the pump. toggle switch to provide low voltage to turn on/off the relay's contactors.

OK, I found a fog lights relay in my car so here it is:

30 = +
86 = -
87 = 1st Fan’s +
87a = 2nd Fans + terminal (not sure if a 30 amp relay can support 2 fans)
85 = T-stat or Toggle Switch

I disagree with the wiring of a 'bosch' style 30amp relay described above.


The terminals of a relay are defined as follows:
30 is the common or input voltage (or ground) to be switched.
87a is the normally closed connection (can be used as a switched voltage output when the relay is at rest). (This terminal offers no voltage when the relay is energized.)
87 is the normally open connection (switched voltage output when the relay is energized).
85 is connected to the ground of the triggering voltage.
86 is connected to the positive 12V of the triggering voltage.

Note: in many cases, the connection of pins 85 and 86 can be interchangeable, but NOT if there is a diode wired across the coil.

You will need a seperate relay for each electric fan, as well as fuses.

http://www.partsexpress.com/resources/relayatrest.gif

John

glad someone's watching. I transposed# 85 and 86.

No actually it 87a which is the normally closed position, so the way it was described is fan2 would run until the engine got to temp and fan1 would come on and fan2 would shut off.

John

Some relay will only have 4 terminals. meaning the 2 fog lights will be connected to terminal 87. the one I use has 5 terminals; 87 & 87a - each light has its own terminal

I have never seen a relay that has both 87 and 87a normally open....

Can you post a picture of the schematic on the side of the relay, so I can file under 'things I have never seen until now'

Cause I know I have not seen it all.

J.

how about the fuel pump???? is it the same way but with one relay...