I know this has been beaten to death but I just waded through 50+ pages of the mega thread and no one was explicit enough explaining how to bridge the high and low cooling stages on the fan so the fan comes on in high when the car is calling for low speed. AKA, my resistor burned out and I just want the fan to run in high whenever the car calls for cooling. AKA A/C...

I've seen people say splice the two stages together, the red/blue 4mm and the red/green 2.5mm should be spliced together. Does this mean I literally splice the two ends on both sides? If someone has a picture I would be extremely grateful... I can see the 2 cables you all talk about.. and yes I can strip them and splice them together... but do I leave BOTH cables connected to the fan connector from my car in my engine bay? or splice both cables together and then cut the 2.5mm or the 4mm side going into the connector?

I've included a crude picture to show what I THINK I am being told to do.

Please correct me if I am wrong and no I do not want to do the resistor fix for now... Thanks, just want the high speed fan to run when low speed is called for aka when my a/c is on...simple fix because I don't care about noise or power draw or fan life...

 

For about $68.xx w/free shipping (Amazon) and just slightly over an hour of your time, you can replace the entire fan unit, which (IMO) is a much better option than permanently altering the car-side fan connector/wiring and listening to a very loud fan that won't last long if it's only running in high-speed mode.

 

I'm really not interested in that for my question. Thank you though. The question is how to splice the wires to get the low speed stage to trigger the fan so AC will call for the fan to be on.

I already have a replacement fan I will install after this one dies. So please if anyone knows the answer to my question, let me know. I'm not interested in other solutions as I am already aware.

 

Totally agree on spending the small investment to fix this part of the cooling system.

Just did this repair with my son on his car and it was straightforward.

Monitoring the coolant temps through the OBC, they are steadier and more consistent, less swings into the 110+C range. More importantly, the fan doesn't run on high after the motor is turned off.

 

Guys, I sure do appreciate you trying to recommend things to me but I already have the resistor and a new fan and can splice it in at any time, my question still stands about how to do what I'm asking to get the low speed stage to kick on the high speed fan.

I'm not interested in any other solutions, just how to splice this correctly. I already have the resister to fix this and a new fan assembly for the future, but that's not what I'm asking how to do right now.

 

Shot term....checking the cars wiring might work...
But long-term...look at the effect of the back feeding voltage from the "paperclip" mod to add extra brake lights....fried BCMs...
Cheap mod, $$$ fix.
Been saying you years....don't mess with the cars wiring....
Nothing is as $$$$ as going cheap....

 

+1
Been saying it for years.....
Like I said above....folks love to save a few ¢ just to have to spend $$$$ to fix the problems caused by it....
If you want to do the "splice" add a blocking diode....if not, you are back feeding voltage up to the controller on the wire you splice into...
Yes... gets messy fast....

 

The wires lead to the relays. When the high speed relay is on. The low speed relay is off. So even if they are spliced shouldn't the relay being off mean it's not being sent any voltage for potential damage because the relay is not allowing current through? So it shouldn't matter if you splice them together is my thought in regards to back feeding power anywhere. The relay that's off stops this.

When the high speed relay is off and not providing power. The low speed relay if open would send power back to the high speed relay due to the splice which is shut off so it is not allowing power through to back feed anything. The two relays are either both not allowing power or one is on and one is off. Never both allowing power. That's my understanding.

If I'm wrong please correct me.

I still need to know if my diagram is correct for how to splice. Not all the opinions or possible negative effects. No one has answered my first question yet. I really do appreciate the advice, but I'm looking for somebody to answer my question of how.

 

You mentioned in your question that you didn't want to do the resistor fix, so I didn't suggest the resistor fix.

I suggested (and still suggest) fan replacement.

 

patsum, your diagram is correct. Run a jumper between the two wires as indicated by your red line. Super easy with a quick splice or (even better) Posi-Tap connector.

 

Perfect.
RKW,
Thank you for your help. My whole point of this question was to figure this out so I can just test for my own interests and purposes. Not to leave it like that permanently. I do have the correct fixes I'll install after. I just want to try this first for my own curiosity and so that other people searching online can find a clear-cut visual for this procedure as well.

Thanks again!

 

This thread proves that there will never be the possibility of "a really quick cooling fan question." Hence the 100+ page thread on the subject.