"Fan delete mod"

**isolatos** · 04-01-2010, 08:28 PM

Originally posted by bimmer95

If you want to add a puller fan that won't kick on with the AC, try this...

So I hooked up this way using the blk/brn wire and the fan never came one. I used the test light and when I touched the blk/brn on the relay the fan went on. I am guessing I need the new rad switch?? Or is that wire only work when a/c is on? Just thought of that.
Thanks

**flyboyx** · 04-02-2010, 06:05 AM

why would you want the fan to work independently of the air conditioning? the factory designed it that way for a reason. if you delete a/c then the fan would only come on when the engine is hot anyway. why not just use the factory wire that runs to the stock fan? if you have a single speed fan, you can hook to the low speed wire and the ground. since the wires are already heavy guage, switch from a 15 to a 30 amp fuse(or whatever the fan manufacturer recommends) bam! all done! what am i missing here?

**7pilot** · 04-02-2010, 07:55 AM

Originally posted by MattM

so the M20/M50 thermostats are the same size? so i could put the 75* from my M20 into the M50?

I would buy a new one for peace of mind.
These engines run hot as normal, so the safety margin for the head gasket is lower, than for the older engines.

m

**isolatos** · 04-02-2010, 06:27 PM

I cant get the switch to fire my fan. I have now wired it to the original fan plug so I manually turn it on with the ac button. This cooling system has been the worst Ive ever had to work with!

**motorsports_3** · 04-02-2010, 07:44 PM

Originally posted by flyboyx

why would you want the fan to work independently of the air conditioning? the factory designed it that way for a reason. if you delete a/c then the fan would only come on when the engine is hot anyway. why not just use the factory wire that runs to the stock fan? if you have a single speed fan, you can hook to the low speed wire and the ground. since the wires are already heavy guage, switch from a 15 to a 30 amp fuse(or whatever the fan manufacturer recommends) bam! all done! what am i missing here?

Everyone seems to recommend against that, to run the relay system or a separate thermo.

How do you wire it with the a/c?

**flyboyx** · 04-02-2010, 07:59 PM

Originally posted by motorsports_3

Everyone seems to recommend against that, to run the relay system or a separate thermo.

How do you wire it with the a/c?

well, its very easy to hook it up to run a/c. just do as i mentioned above. if you don't have a/c also do exactly as i mentioned above. the a/c circuit and the temp circuit work in parallel to run the fan anyway. i really can't make any sense out of why anyone would not want to use the stock circuit the way i described?

:(

it is a really good system and it works great as designed by the factory. i have my "improved" aux fan hooked up the stock way and it is great. works exactly like it is supposed to and better. i completely understand that everyone here on this forum has different levels of experience. however, we are making this way more complicated than it needs to be. i also think people are trying to redesign the fan electrical system simply because they don't understand the factory one. the truth is, you don't have to understand it. all you have to do is figure out which wire is ground,(a hint: its brown and shortly after the plug it terminates at a bolt on the inner fender) then you have two wires to choose from. one is low speed and one is high. on most cars they are black/red and black/green. it is plausible that one could actually check the etm to see which is high and low. if that is too complicated, just try one. if the fan switches on too warm for your taste, switch to the other one and replace the 15a fuse in the low speed circuit with a larger one. there is no rocket science here. forget the wiring diagram posted above and do it the easy way.

**bimmer95** · 04-05-2010, 12:01 PM

Originally posted by isolatos

So I hooked up this way using the blk/brn wire and the fan never came one. I used the test light and when I touched the blk/brn on the relay the fan went on. I am guessing I need the new rad switch?? Or is that wire only work when a/c is on? Just thought of that.

I made that diagram for E36s, you'll want to double check the fan switch wire colors on your E30. On E36s at least, the fan circuit only has power when the engine is running, not when the ignition is just switched on, regardless of whether the AC is on or not.

**flyboyx** · 04-05-2010, 09:47 PM

Originally posted by bimmer95

I made that diagram for E36s, you'll want to double check the fan switch wire colors on your E30. On E36s at least, the fan circuit only has power when the engine is running, not when the ignition is just switched on, regardless of whether the AC is on or not.

on e30's it should run with the ignition in the "on" position. you can check this by turning the ignition switch on, taking the plug off your radiator temp switch and jumping the terminals. be sure to check your etm so you know which wire is ground.

**isolatos** · 04-06-2010, 08:37 AM

Just drove it again. No thermo, fan on constantly. Drove 10 minutes in city and the car got to 225. Pulled over and the passenger side of the radiator is ice cold, sstem is pressurized, motor is hot, coolant is warm at cap. Any ideas? It doesn't seem like te radiator is clogged, I did a reverse pressure flush and it seemed to flush fast.
Thanks

**bimmer95** · 04-06-2010, 10:32 AM

Either you've got a massive air pocket or your water pump is toast. Early E36 water pumps used an orange plastic impeller which had a nasty habit of breaking loose from the shaft or blowing completely apart. I've got a quick write up on swapping the pump and how to properly bleed the cooling system here, http://www.understeer.com/waterpump.shtml

**isolatos** · 04-06-2010, 06:22 PM

The pump is new and has a metal impeller. I bled the coolant 3 more times using different methods with the same result. When I rev the car I can see coolant squirting into the resevoir like crazy. I pulled the radiator and am taking it in to get checked tomorrow. Any other advise?

**isolatos** · 04-06-2010, 06:38 PM

I just checked all of my spark plugs to see if any of them looked different and they all look the same. Also my oil looks great, no milkyness

**dude8383** · 04-07-2010, 07:27 AM

It took me a LONG time to bleed my system when I completed the swap. You might have to bleed it another 3 times just to get it right.

**Fusion** · 04-07-2010, 10:16 AM

I agree with dude. My last heating issue http://www.r3vlimited.com/BOARD/showthread.php?t=165963
Seems it was all caused by air in the system bcause I've been doing some work on my engine, swapped the heater core lines and as I took them off, there really wasn't a coolant spill, so I had air in there.
I'll be lifting the front when I get done to bleed it again.

**bimmer95** · 04-07-2010, 10:24 AM

You've got to start with a cold motor and rev the motor quite a bit to bleed it properly. Most folks try to bleed at idle and end up failing miserably.

"Fan delete mod"

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment