My cooling fan turns on when the A/C is running, however it will not turn on when the engine warms up. I opened up my service manual and the electrical diagnosis says the engine heat sensor won't turn on until it hits 238F. 238F sounds very high. I thought engines were supposed to run around 190 - 210F. Is 238F correct? My last 305 would smoke real bad once it got over 220F, only occuring in heavy summer traffic. This one is not smoking but I always shut it down once it gets up to 220. Should I run this engine up to 240F and see if the fan turns on? What's generally considered a safe maximum temperature for the 305 TBI (L03?)?

 

You can put a lower temp fan switch in. I run a SW555 I think and it comes on around 205-210. It is the replacement fan switch for an 89 Turbo Trans Am. Jet makes them that will turn on even cooler but I think 205-210 is optimal. I agree 235 is too hot.

 

SW555 is my favorite with a 180 degree thermostat it came factory in the 1989 3.8L turbo trans am I believe 212 on and 205 off. Works great for me and is a direct swap over factory.

Here are some alt part numbers

WVE/AIRTEX/WELLS 1S4394 {#3053190, SW555}

https://www.rockauto.com/en/moreinfo...933036&jsn=449

 

I'm having difficulty locating the cooling fan switch. The manual for the L03 (VIN E) shows it somewhere on right side rear of engine block. Can't get an eye on it, should I lift the vehicle and look from underneath?