So ive got a 91 prelude, very nice. One problem: when the ignition is turned foward, this is the key, the cooling fan shuts off. The temp sensors are working fine because if you let the car run untill it gets to the point that the fan should turn on and then turn the car off, the fan turns on. But then when you turn the key foward, the fan shuts off. Fan will not start with car running. For now I hard wired in a switch and just watch the temp gauge. ANY IDEAS??

 

I believe this is normal operation. That's how the fan is wired. At least on my CRX's and my '91 teg. I'm assuming they do this becasue there is no need for the fan if you are moving. Or to save power for cranking.
I know my teg with A/C has a small ECU that controls both fans and it has a lot of sensors going into it. Maybe '91 preludes are wired the same.
If you don't have A/C though they dont have the fan ECU. At least with 2G tegs you don't.
HTH

 

No, its not normal because before I put the hard switch in, I could let the car idle for 20 minutes and overheat. ( I got caught in bad traffic and had to shut it off so I wouldnt blow a head gasket.)
I dont do this, but you can turn the car on and let it idle for a LONG time and the temp gauge will go all the way up to "H".

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by matt_ackerman2000 &raquo;</TD></TR><TR><TD CLASS="quote">No, its not normal because before I put the hard switch in, I could let the car idle for 20 minutes and overheat. ( I got caught in bad traffic and had to shut it off so I wouldnt blow a head gasket.)
I dont do this, but you can turn the car on and let it idle for a LONG time and the temp gauge will go all the way up to "H".</TD></TR></TABLE>

Above could be correct. But, 1st find out if your car has "an A/C fan timer" or fan control module, as it's sometimes called, and then have it checked. Thats a better route than wiring in a switch. JMHO.