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Topic: E fan relay diagram (Read 2606 times) previous topic - next topic

E fan relay diagram

Me and Jacssity came up with this one night, I just got around to painting a diagram of it.
 
It's of the fuel pump relay ( green 4 pin relay) from my 84'. As set up accodring to the diagram, this "should" work. I'll update tomorow for a yes/no but here is the diagram

E fan relay diagram

Reply #1 –
thats not exactly what i said,,,,

you need a fuse inline with the batt wire and pin 3, pin 2 is ok.
(polarity !!!!!!!  get it right or you blow the diode possibly)
and
route a wire from batt to pin 4 with inline fuse
and route a wire from pin 1 to fan input
and route wire from fan ground to chassis ground

this wiring you want leaves no control measure in place so its manual.

That toggle switch is not hot!!,,, it is located on the ground side of the relay coil,, it will not be hot unless the ground becomes open (no sparks flying up in the dash)


there are two paths in a relay, look at some examples in electrical tech.  Remember how i had you use that 6v battery to energize the coil and you heard a click>?  That was another separate circuit (pins 1 to 4 making contact)
The coil is polarity sensitive,, the contacts are not.

The fuse required on the coil side of the relay wont be that high, thats why pins 2 and 3 are smaller.  Id suggest no more than 5 or 10 amp but you can figure that out.

the contact side of the relay will need to be fused at 80% of fan rated current draw. Also your relay ampacity should be way up there as well such as the relay that came with the fan.  The fan will draw a lot more than rated current on initial start so dont be surprised if you blow fuses off the get go.  I wouldnt be surprised if you find a 30 amp fuse does not last long.  You need a "slow blow" fuse in order to get the amperage lower on the fan side of the relay.,, otherwise you might find that the resetable fuses like found on the power seats ect would work best.

just dont burn down your car

id suggest you use the resetable fuses for testing and initial setup so you see what works and what does not.,,, otherwise you might start running out of fuses and be temped to not use a fuse at all.  DONT DO THIS,, FUSE THE  THING>!!

E fan relay diagram

Reply #2 –
Quote from: jcassity;175935
thats not exactly what i said,,,,

you need a fuse inline with the batt wire and pin 3, pin 2 is ok.
(polarity !!!!!!!  get it right or you blow the diode possibly)
and
route a wire from batt to pin 4 with inline fuse
and route a wire from pin 1 to fan input
and route wire from fan ground to chassis ground

this wiring you want leaves no control measure in place so its manual.


So with it wired like that it will be live and runnning with the ignition (which is what I want) right?  Mine right now is running off the coil power and just grounded out.  I know it isn't right but it is working for now, the only issue with it, is it makes the engine keep running til the fan stops.  and it is sometimes hard to start, as it is drawing voltage from the coil.

E fan relay diagram

Reply #3 –
Quote from: 1WLD BRD;175951
So with it wired like that it will be live and runnning with the ignition (which is what I want) right?  Mine right now is running off the coil power and just grounded out.  I know it isn't right but it is working for now, the only issue with it, is it makes the engine keep running til the fan stops.  and it is sometimes hard to start, as it is drawing voltage from the coil.



I suppose you could run it off the ign sw.  Mikey wants to control his manually so this is wired off the battery and independant of the car harness.  If i were to go to a manual control fan, i wouldnt wire it through the ign sw.  Having said that, remember, the toggle switch i have drawn will only require one wire to feed it which is on the ground side of the relay coil (low current),, therefore, its prob ok to wire the ground side of the toggle sw to an ign sw ground wire that "becomes" ground when the key is turned on.

Older GM cars used the coolant temp sending unit to get a ground for the fans from what i remember.  The 2.3 uses the computer to control the ground supplied to the electric fan relays (pins 55 adn 52).

the 3.8 eec has pins 55 and 52 controlling the egr solenoid and the exhaust heat control solenoid.

the 5.0 has no reference to using these pins.

I dont see a common denominator on any of the tree eec's and thier applications on ground supply based solely on coolant temp.  I wish there was though.

E fan relay diagram

Reply #4 –
Mikey,
take a look at my drawing and then yours.  I kind of laughed a little cause i know how (how do i put this...) eagar you are and such but. that circuit wont work,,non functional,, no power ,, no fan,, nope,,, nothing. :D

take a relay apart and it will suddenly "click", no pun intended.:hick:

as for locating a high amperage relay to do this,,,,,use the relay that was in the car that came with the fan or like wise find one.  I think the highest amperage relay in our cars is the fuel pump relay.  Pehaps the power seats are higher amperage but i dont know, never checked.  Rule of thumb, if the relay controls a circuit that powers a motor assembly of some sorts, its probably a higher current rated relay.
 

E fan relay diagram

Reply #5 –
They sell the kits at the autoparts store. Just go by one. It comes with the instructions. Much easier.
brian