oil cooler fan wiring?

[francesconyc]

I got a SPAL fan, brackets, and the SPAL harness with relay fuse and wires (see pic) for a carrera style fender oil cooler.

I understand I will have to pass the cable going from the fan through the fender holes to the frunk, through that hole, I will have red and black wire.
the black wire can be connected to any ground connection, like the body of the car or directly to the battery.

then I understood RED wire needs a fuse, which I guess I can connect right there between the fan and the relay RED wire.

Now, the relay wires are marked as:
- yellow: battery 12v
- red: to the fan red wire
- orange: ignition
- grey: sensing unit


yellow and red are easy to understand
but I dotn understand grey and orange.

I don't have a thermostat for now, aka sensing unit, I'm thinking of keeping the fan on all the time when the engine is on for the time being, (add a manual switch for now). (one step at the time!)

so what do I have to do with this grey wire?
in theory... can it be connected to the same wire of the oil thermostat that goes in the oil temp gauge?

and the orange what is supposed to go? to the fuel pump fuse?

thanks for the help

[francesconyc]

ok im answering myself part of the question

I found this diagram
which clarifies and corrects my assumptions on the fuse position


but I still don't understand what to do with the grey wire and the ignition wire

can I connect the grey wire to the green/black wire that goes to the oil temp gauge? where do I find that wire? where is it running?

can I connect the ignition directly to any of the fuses that switche on only when the ignition is on?

[911obgyn]

Grey wire grounds the coil in the relay ,ignition is the power to the coil. Should be hooked to a wire that is hot while running.

[mike sampsel]

Originally Posted by francesconyc

ok im answering myself part of the question

I found this diagram
which clarifies and corrects my assumptions on the fuse position


but I still don't understand what to do with the grey wire and the ignition wire

can I connect the grey wire to the green/black wire that goes to the oil temp gauge? where do I find that wire? where is it running?

can I connect the ignition directly to any of the fuses that switche on only when the ignition is on?

Grey wire connects to the sending unit, this measures the temp in the cooler and runs the fan when the oil temp reaches a certain point. Since you want to keep the fan on all the time, the grey wire can go to any ground. You can use a switch if you want to be able to toggle the fan.

Ignition wire, along with the grey ground wire, activate the relay circuit to on. Orange can go to any output that is hot when the ignition is in the on position. So the fan only runs with the key in the on position. This is desirable as you do not want the fan running all the time. So find a covenant 12 volt source which is 12 volts with the key in run position and 0 volts with the key in the off position.

[wazzz]

If you really plan to have the fan run all the time, I suggest you connect the grey wire to the yellow wire that goes to the starter solenoid, in the same way as for all other secondary components like heater fan, A/C blower fan, etc.
That way the fan will stop running temporarily when cranking the engine and all battery power will be dedicated to solenoid and starter only. Useful when battery is not fully charged and weather is cold.

[boyt911sc]

Originally Posted by wazzz

If you really plan to have the fan run all the time, I suggest you connect the grey wire to the yellow wire that goes to the starter solenoid, in the same way as for all other secondary components like heater fan, A/C blower fan, etc.
That way the fan will stop running temporarily when cranking the engine and all battery power will be dedicated to solenoid and starter only. Useful when battery is not fully charged and weather is cold.

Gilles,

The GREY wire in the schematic diagram is ground (-) and the YELLOW wire to the STARTER is positive (+). Connecting these 2 wires will cause a SHORT in the circuit. Please tell me I am WRONG. Thanks.

Tony

[mike sampsel]

Originally Posted by wazzz

If you really plan to have the fan run all the time, I suggest you connect the grey wire to the yellow wire that goes to the starter solenoid, in the same way as for all other secondary components like heater fan, A/C blower fan, etc.
That way the fan will stop running temporarily when cranking the engine and all battery power will be dedicated to solenoid and starter only. Useful when battery is not fully charged and weather is cold.

Problem solved if the OP adds a manual switch for the ground, although the orange wire can go to any lead that is 12 volts with the key on. Preferably one that’s not 12 volts when cranking, but the ground switch shuts it off when enabled.

[wazzz]

Originally Posted by boyt911sc

Gilles,

The GREY wire in the schematic diagram is ground (-) and the YELLOW wire to the STARTER is positive (+). Connecting these 2 wires will cause a SHORT in the circuit. Please tell me I am WRONG. Thanks.

Tony

Indeed, a ground is needed on the grey wire for the relay coil and you can connect this grey wire to a real true ground and forget about it.
Or, you can connect it to the hot side of the starter solenoid (yellow wire coming out of the ignition switch). That way, in normal running situations other than cranking, it is seen as a ground through the solenoid, since the solenoid is a small resistance and because the relay coil only draws a small current. Check all diagrams for heater, A/C, etc. This is the way they did it in order for these secondary components to stop running (if they are On) while cranking. Most automotive builders, including Porsche, use this trick. Very clever I think.
I have already seen threads here and there where people are wondering why the starter solenoid is shown in the diagram for a component such as heater, AC, etc.

Here is a diagram for the cooler fan from Bentley that I edited with colors to explain it better.

[francesconyc]

Originally Posted by mike sampsel

the grey wire can go to any ground. You can use a switch if you want to be able to toggle the fan.

Ignition wire, along with the grey ground wire, activate the relay circuit to on. Orange can go to any output that is hot when the ignition is in the on position. So the fan only runs with the key in the on position. This is desirable as you do not want the fan running all the time. So find a covenant 12 volt source which is 12 volts with the key in run position and 0 volts with the key in the off position.

fantastic thanks, this is the confirmation I needed! thanks

I saw the oil cooler (carrera style it is supposed to have its own temp sensor...who know if I have it... when I install the fan I will check it...

since I'm removing the fog lights, I'm almost thinking to connect the fan to that switch to have a nice clean button that I can a custom icon for

[francesconyc]

Originally Posted by wazzz

If you really plan to have the fan run all the time, I suggest you connect the grey wire to the yellow wire that goes to the starter solenoid, in the same way as for all other secondary components like heater fan, A/C blower fan, etc.
That way the fan will stop running temporarily when cranking the engine and all battery power will be dedicated to solenoid and starter only. Useful when battery is not fully charged and weather is cold.

yep, I was thinking to pick one of those components that start only after the engine for sure, thanks

[mike sampsel]

Originally Posted by francesconyc

fantastic thanks, this is the confirmation I needed! thanks

I saw the oil cooler (carrera style it is supposed to have its own temp sensor...who know if I have it... when I install the fan I will check it...

since I'm removing the fog lights, I'm almost thinking to connect the fan to that switch to have a nice clean button that I can a custom icon for

Probably okay, be aware that fog lights may be shut off when headlights are in High beam.

[fallingat120mph]

Not sure if this helps...just in case you are looking for ideas.

When I was in the process of transferring an oil cooler fan from one of my 86s to the other one, I was finding a few threads with folks using a rear wiper switch for a on/off fan button.

Complete honesty - I was just getting my feet wet with electronics and relays so have started a few threads asking questions not found in Waynes 101 or Bentley, etc...

Anyway, here is my thread from a while back and in the end the rear wiper switch worked like a charm and is actually where my old "headlight water switch" was near the clock. I removed the washer system and the button at that point was useless.
So bought a new rear wiper switch as you can not use the headlamp washer/squirter' switch.


https://forums.pelicanparts.com/porsche-911-technical-forum/1158244-electrical-wiring-question-front-oil-cooler-fan-86-coupe.html


Erik