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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHRadiator fans not coming on
Leading reported evidence
Use a/c
Suggestion or failed attempt
No successful repair reported for this finding.
0
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0
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1
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Suggestion · Original poster
If I dont turn on the fans with the mod the gauge will rise past the zero and this is without using A/C.
Leading evidence: 'Use a/c' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Use a/c' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Suggestion · Original poster
The temp using the hack goes up to 215 and the fans do not come on at all with the A/C off.
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9 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
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I did the fan mod so I can turn them on with a switch however they just dont come on now that its cooler out and I'm not using A/C.
Where is the sensor that turns the fans on?
What do I check?
Need more info for sure.
First thing I'd do is turn the AC back on and see if the fans start up. It's entirely possible that they aren't on because it's cool out.
The reason I asked what year his car was is that if it's a Mk 1, he could do the coolant temp hack which, though imperfect, is more informative than the gage. That way, he could get a rough idea of whether the engine is warm enough to fire up the low speed fans or not, maybe
get
it warm enough, and then see if they kick in. This could be a big nothing.
My car is a '99. The fans do come on with the A/C in both low and high speed. The temp using the hack goes up to 215 and the fans do not come on at all with the A/C off.
I turn them on manually using the switch I put in and can maintain 185-195 degree coolant temps.
My original question - what turns them on and where is it?
The ECU looks at the temperature of the coolant and the status of the AC unit and then trips a couple of relays to operate the high or low status of the fans.
I have done the "fan mod" in my 99 c2 as well... it would be nice if I an install a relay to activate the high speed fans @ 185 automatically instead of me flicking the switch..... does anybody know how I can do this... a relay... don't really understand how that works...
Does anyone know the answer to my original question, where is the sensor that turns on the fans. If I turn them on with my switch the temp gauge needle sits dead center of the 8 and the 0. If I dont turn on the fans with the mod the gauge will rise past the zero and this is without using A/C.
What do I check?
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