dmoffitt

does anyone know what kind of resistor is used for the "slow" fan speed? i'm setting up my own switch in the car to... well, not to override but to offer me more control over the fan speeds.... plus i have a bad under-hood relay so i'm re-wiring the fans my way.

can anyone offer suggestions based on this wiring diagram and what i'm trying to do?

<a href="http://boards.rennlist.com/upload/dm-fan_speed_sw.gif" target="_blank">http://boards.rennlist.com/upload/dm-fan_speed_sw.gif</a>



basically the car will operate as normal (factory/stock) when the in-car switch is set to "off". when it's on "L" (low) the rans will run, even if the car is off (ie, for autox). same for "H" (high) - but also not just when the car is off, i can see myself using that when i know i've been driving harder and am going to soon be stuck in traffic, say, at a toll booth.


anyhow, suggestions / ideas would be appreciated, and i'd really like to know what resistor to use to make it the same opperation as the stock setup.

edit: i came up w/ another way (actually, i came up w/ this idea first) where it simply turns one fan on for slow, and both, for fast. note i don't think i used the right symbol for diode (and this diagram uses 2 switches, not a 3pos, but can be switched with either).



thx! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

dmoffitt

oh, and if anyone knows of freeware wire-diagram software plz lemme know (i suppose i could use adobe illustrator but that's not exactly effecient) cuz these hand-drawn sketchs aren't doin' it for me

yoyoguy2

those diagrams look a lot like my final exams, mostly unreadable by anyone but an engineer

they both look like they'd work to me, if you go with the first one i'd just experiment with different resistors to find a good value that gets the speed you want. you'll have to score some big resistors though, the 5 cent radio shack ones can't handle the current of the fan motor (or you could use a bunch in parallel, but that would get out of hand)

if you go the second way, with the 1 fan or 2 fans option, i'd do it like this:


same idea but uses another relay instead of the diodes (i hate diodes ), just a little simpler. your way should work just as well though. i didn't include the temp sensor but you would just throw it in parallel to the switch. don't know if i actually answered any questions... HTH at least a little....

dmoffitt

wow, awesome! i hate / misunderstand diodes too, and am glad i can do it w/o using one *whew*

i think i'm gonna try these resistors i bought (1ohm, 10a max, 2-pack) and see if either in parallel or series, they bring it down to the right speed... but otherwise, i think that diagram you posted will be what i am after.

thanks!!!

toddk911

Running those in series will cut your Res. in half.

I have also done some tweeking with my fans as I had one that had loose wires and I live in Florida where I am tired of my car running so hot.

By coincidence of testing out relays to see which one was bad for another problem, I put a basic relay (flasher) in place of the AC relay (as I don't need AC now )and when the car is on, both fans run all of the time. The car runs MUCH cooler and runs better do to the engine running much cooler. Once in a while they run and hihg spedd, but quickly slow to normal speed.

Question: Is it possible this is bad to do as the temp sensors will not read a high enough temp to let the coolant run through the engine properly? And thus making it an air cooled motor?? <img src="confused.gif" border="0">

dmoffitt

ok, i'm rather frustrated, i tried wiring everything up tonight, and i was HOPING to retain the factory wires, and just pull out the annoying huge g10 (silver / double) relay, and run leads from it's contacts to my own relays (and my switch). unfortunately, after practically "dissecting" the central-electric / fuse box, i couldn't seem to figure out which wires to look for (stupid me, i left my manuals at home in ny... DOH). on the other hand, ironically the fans worked perfectly (both high and low speeds) when i put everything back together and so that leads me to believe that the temp. switch (aka fan switch) in the radiator might well be the culprit of my intermittent fans-not-turning-on issue.

actually, it's quite odd now, as the low-speed doesn't turn on, but then it'll kick into high as the temps climb, and once it's dropped, the low speed DOES work... i'm really quite tired of how hideously complicated and ridiculous our fuse box / central-electric is, and would LOVE to have a friend or two at school (RIT, home of LOTS of EE / MicroE people) help me rewire the whole car, and run a lot of this crap off of a microprocessor (*yeah yeah, pipe dream* but i can hope, right?). it's just that, to me, well, 16-year old convoluted stuff isn't exactly fun to troubleshoot / repair / upgrade

so, does anyone have a scanned copy of the pages in the manual that show the fans' wiring, the temp. switch's wiring, the g10 relay, etc? if so could you email them to dmoffitt@rochester.rr.com (if they're under 5mb). thanks!! (i'm also very open to suggestions lol) <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" /> -- aaah, i needed that (considering i've been working on this the past 5 hours )

yoyoguy2

[quote]Originally posted by toddk911:
<strong>Running those in series will cut your Res. in half.
</strong><hr></blockquote>

i believe you mean in parallel.

[quote] Question: Is it possible this is bad to do as the temp sensors will not read a high enough temp to let the coolant run through the engine properly? And thus making it an air cooled motor??
<hr></blockquote>
i don't think this would make it an air cooled motor by any stretch, but i know on some japanese cars the ECU runs a different air/fuel mix when the engine is cold, to warm it up more safely. if this was the case on our cars, which i don't know if it is, it would cause reduced power and poor gas milage. friend of mine got an exta 10 mpg by puttin a new thermostat in his eagle talon.

dmoffitt, i've got the pdf of the factory manual, i can send you the electrical part if you want, but it's gonna be over 5mb so i assume you're email account can't take it... i've also got a haynes manual, i don't recall if there's a good diagram in that i could scan, i'll take a look...

dmoffitt

hmm, i've got it at home and if i recal it's HUGE (something like, oh, 5-600mb for all the files, each being 80-100mb-ish). I think i'm gonna just give up on using the factory wiring, and make my own connectors/harness (so that i can preserve it at least, in case I decide to go back to stock)... thanks a ton for the offer tho!!

anyway, please direct any comments/suggestions/ideas to the new thread at <a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=003387" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=003387</a> (i started it cuz this project is getting waaaay outta hand and expanding far beyond the scope of just re-wiring the radiator fans...)

thanks again!!