Shared this idea with my local mechanic yesterday, who is intrigued. His only question, which I can't really find an answer to here:

When connecting the smaller wire (low speed) back to the larger one (high speed), do any issues come up with the power "backfeeding" up the large wire and causing any issues? If the car is sending an input down the low speed wire, it's not expecting any power to be on the high speed wire - which we've now introduced by connecting the two. I assume any issues from this would have been brought up in a 48 page thread, but thought I would ask why there wouldn't be any issues from that.

Thanks again for the great idea!

 

Quick answer no.

Both the feeds are relay switched so it will backfeed but only back to the relay which would be open and no further.

 

Good answer - and I assume there would never be a time where both feeds would be live at the same time - it's either off, low or high; no combination of any.

With the weather getting better, and A/C season right around the corner I'll be doing this "fix" soon. Just unsure of the best place to mount it as I've never done any "tapping" and don't want to try it on my car. Mounting to a plate, and then mounting a plate via an existing bolt somewhere is like the way I'll go.

Thanks again, Chris!

 

I have had this fix in place for over 10 years, still running my original fan. More that a few replaced theirs and have probably had to fool around with it again if they kept the MINI.
Just do it and move on. Best advice I can give.

 

Hoping someone can give advice. My fan resistor blew and within a few months the head cracked as a result. Rebuilt and running fine now (new head, Amazon resistor) but now the heater is lukewarm so I watched the coolant temp thru OBD/Inpa at idle after a short drive and for 5-10 minutes it hovered right around 195F as expected, sans fan. Revving to 3K got it to heat up to 210F and still no fan (temp gauge still centered). At 210F I turned on the A/C and the low speed fan quickly came on, I turned the A/C right off and the fan remained on, dropping the temp back to 195F and staying around 185F-200F, low speed fan on. Now I'm worried that the fan might again fail to come on sometime.

Both fan speeds work, this is the '03 with the high speed relay in the fan. Inpa can turn on both "low" and "medium" speed fans. Everything seems normal there.

The second oddity is that at idle and 195F with the fan running I can yank the low speed relay out of the fusebox and the low speed fan will stop for about 1-2 seconds before coming right back on at high speed. Inpa shows 195F during that 1-2 seconds and a IR thermometer on the radiator confirms. How does it know to turn on the high speed fan so quickly? I can do this over and over again with the same result.

So I have 3 concerns:
- low speed fan failed to come on once and let it idle up to at 210F (sticky relay?)
- High speed fan somehow knows to come on the second I pull the low speed relay (psychic?)
- Heater is lukewam (clogged core or valve due to oil contamination from the cracked head?)

What do you guys think?

 

- Low speed fan will kick on at 220*
- Make sure you 'burp' the system with the heater running so it pumps coolant throught the heater core.

 

Thanks 808, I just get nervous about temperature deviations after cracking the head. I'll try again and confirm that it comes on at 220F.

As for the high speed fan coming on almost immediately after I disable the low speed, I realize that there must be a second temp sensor after the radiator to determine the fan needs, so that would explain the fast reaction.

I'll keep trying on the coolant bleed. I've got about 10 miles on the car with the heater on and have opened the cap and front bleeder many times. I see now that there is a heater bleeder that I was unaware of -- hopefully that'll do the trick!

 

When you head cracked <G>, what were the symptoms? Before I last changed my fan for the 5th time (2003 MCS) I overheated (no smoke but the gauge pegged and I looked at my data. Artoo still runs strong and pulls up to redline, but it is consuming more oil than ever (a quart every 500 miles) and I really have been diligent with leaks. And he consumes not a drop of coolant. It didn't get over 225 but when I think about it, I think bad thoughts.

///Rich

PS-Artoo just passed 150,000 miles. I love driving him and really don't want to make a change.

 

At 100K miles I was cruising at 50mph and the temp gauge suddenly pegged. Engine didn't feel abnormally hot when I opened the hood on the side of the road but it sure needed a lot of water. Got home (2 miles) with normal temps and added a bunch more water. I then found that the oil pan was very overfull with chocolatey soup and the coolant was oily and dark. I had just changed the oil 2 weeks prior and checked the oil 1 week prior so I knew this wasn't a long term buildup.

Cylinders 2 and 3 were both low (120psi) and since the single oil passage goes between 2 and 3 and is surrounded by coolant passages it seemed like a head gasket slam dunk. Turns out the gasket looked fine and the head wasn't warped so further investigation was needed by a machine shop. I had no idea that engines still crack, I thought that was something long gone from the 1970's along with burnt valves and worn camshafts, but as it turns out, all those things still happen to modern cars for some reason. My next car will be electric.

Anyway, head was clearly cracked near the timing chain allowing coolant to spray on the chain. The crack ran across the gasket face and up the chain wall and was clearly distinguishable from the many scratches as it was somewhat jagged and "blurry". I never did figure out how oil got in the coolant or why the compression was low. Maybe another crack near the 2-3 bolt or maybe the gasket was indeed leaking after all? Oil cooler was tested and re-used. Supercharger gears were bone-dry but in good condition. Oil pan and crank sensor were leaking like crazy, especially the crank sensor.

5 fans?!! Were these aftermarket fans? I was worried about that so I took the much more difficult approach of replacing the resistor. Has anyone had one of the Amazon resistors fail yet?

 

Ditto what he said, plus, is your A/C on, that should make the fan run because of pressure in AC, and is not dependent on coolant temp at all.

 

I don't think this solution is good. because the resistor can get very hot in summer and without air cold.


I think you can use this solution:


use two benz cooling fan 0.6ohm resistor. you can get 0.3ohm. in summer the resistor can be cold down by air and in winter the resistor can be warmed by engine .


the resistor is

 

The resistor in the first pic does not overheat in summer as it is not air cooled its joined to the aluminium strut with heat conductive paste, the whole thing is one big heat sink!

the second mod you show involves stripping the front end of the car, that's why the first mod was invented its a half hour job, permanent fix.

 

More like a 10 minute job and that includes a beer.

 

I have found myself in this predicament. Actually it is effecting my AC. Read here if ur interested: https://www.northamericanmotoring.co...ure-issue.html

I realize there are 2 options here... One is much less work and the other requiring "service mode".

I don't mind ripping the car apart nor splicing & tapping.

I just would like to use whichever method & part will work better & last longer?

I will go with Dorman from RockAuto if I choose the replacement route.

I know their are many variables to longevity but I'm just curious before pulling the trigger on parts.

Thanks

 

If your fan is working in high speed, and you have a one connector fan, then the external resister is great and will last until the fan motor itself goes bad.

Since I have a 2-connector fan in a 2003MCS, I got a discarded OEM fan and replaced the internal resistor with the Dorman/Detroit Tuned heavy duty assembly. And it has been great so far.

///Rich

 

Finally got around to installing the Arcol HS100 R33 resistor today and now have my low speed fan back. I took the long route and removed my radiator to do it. Cut out the bad resistor, connected 24 gauge wires to the lugs. Ran the wires back (following the fan harness wires) to the front left bumper bolts when the Arcol resistor was mounted to an aluminum plate for extra cooling. Found that mounting tip somewhere in this thread. I do plan later to put slots in the plate holes so the plate with the resistor can be removed without pulling the entire bumper forward. Thanks to all who contributed to the thread

Rich

 

 

I will say this about the Dorman replacement resistor "kit", which are available around the web (got mine from a seller on Amazon) as a FYI. I bought and installed it this past weekend. Had my low-speed fan working again, did some other cooling maintenance things while I was in there and buttoned everything back up.

Next day, I had no fan at all - almost overheated. I wondered if I had done something to kill my fan because I couldn't get it to spin by delivering 12V to the connector plug (yes, while the plug was grounded). I also wondered if the (rather simple) resistor was bad, or if my wire-connecting skills had failed.

But after opening everything back up and doing more testing, I got some intermittent fan response. So... loose wire somewhere. I dug further and found that the green ground wire in the new resistor kit had come loose from its post. I don't know how these wires are supposed to be attached, but there was no solder. It looked more like they are spot-welded on, then covered with black RTV.

I'll have a replacement tomorrow, but be forewarned - those wires aren't very well attached. Of course, I now wish I'd bought the new complete fan assembly but they come with the crappy-style OEM resistor. Can't win, I guess.

 

Yes. Post 1159, I had the same experience. Fixed with ring terminals:
https://www.northamericanmotoring.com/forums/stock-problems-issues/174040-low-speed-fan-resistor-we-need-solution-47.html#post3993348

I found this before I installed the resistor, I had wanted to remove an extraneous wire because I have the two-plug fan design.

I used marine-grade heat shrink, locktite, stainless screws, and the re-potted the terminals with silicone. Probably overkill but the fan motor will die before that comes apart.

 

I concur. New part arrived today (Dorman) same EXACT problem. Wire came off the terminal before I even had a chance to connect it to the fan wire. I used your suggestion and did the ring terminal thing. It works, but I told Amazon that I shouldn't be charged for it.

People: DON'T BUY THE DORMAN RESISTOR KIT (unless you want to modify it).

 

Hi NAM

This forum has proved to be very useful to me since last summer when the power steering on my '02 R50 started getting the hiccups. (Resolved by taking advantage of the extended warranty on the PS pump.)

I have a feeling this thread is going to be of use to me, if only I can find some instructions on how to commit to this fix.

Would anyone be able to point me in the right direction?

I took a look at everything and page 8 jumped out in particular, but still, the pictures aren't helping me enough. I'm afraid I'm going to cut the wrong wire whenever I open the hood!

A few pointers would be very helpful.

Thanks in advance.

 

What, exactly, are you trying to accomplish? Is your low-speed fan circuit dead (open because of a burned resistor)? If so, are you wanting to add the external inline aluminum resistor?

 

Hi Filmy

Thanks for the quick response.

The resistor for my low speed radiator fan is shot. With summer coming and the hot weather in New York approaching, I need to resolve the issue of the high speed radiator fan kicking in when I park on a sidestreet and turn the car off.

It kills my battery

 

If you have an '02, you have a two plug fan and the inline resistor will not work with a simple splice. In order to install it on your car, you'd have to remove the fan and jump the resister on the existing resister.

A better solution once the fan is out is the Dorman wire resister. Much stronger and will work with your OEM fan since the fans themselves seem to never go bad.

///Rich

 

Thanks for the quick reply, Rich. I really appreciate it.

This actually confirms what gear-head was talking about earlier on in this thread around pages 7-8.

Is this Dorman kit what you're referring to?

http://www.detroittuned.com/dorman-gen-1-fan-relay-kit/