yng_750 247 Report post Posted February 14, 2013 so im doing some work on a e36 323i that has had some temp issues. seems the thermostat randomly jammes shut, can drive about 25km at 100kph at normal temp then jumps up very quickly. anyway we have got a new water pump,slightly cooler thermostat, aux belts, rad cap etc etc While we are here we will be installing a 16" electric fan as the fan clutch is getting pretty weak. Having viewed a couple of diys online they use the fan switch as the ground for their trigger feed. They always seem to splice into the high speed side of the plug. ( its three wires so i presume one ground and a high and a low speed relay feed.) Questions are 1.switches that are for sale on pelican parts are a 80/88 switch and a 92/99 switch, am i right in presuming that this car willhave a 92/99 and the 80/88 is just an aftermarket option. 2. would it not be better to install into the low speed side to get cooling asap if it is a 92/99 switch. thermostat is a 89' so fan at 92 would be good right? Thanks in advance Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted February 14, 2013 cars like 318is and 318ti that use a electric fan only mounted on the back side of the radiator , use the lower temp thermo switch. i use one in my 328i with the S/C so the aux fans cuts in earlier . also in my e28 m5 Quote Share this post Link to post Share on other sites
yng_750 247 Report post Posted February 15, 2013 Thanks brent will probably wire into the low speed side of the existing sensor and see how it goes,if its getting warmer than i would like i might order the lower temp one. The only other thing i notice is most people wire the positive feed for the sensor side of the relay from a switched power source in the diagnostic port is there any harm in taking the power (fused of course) directly from the battery? i understand if the relay sticks it will run the battery down but that is not a huge risk, and the benifit would be if the car is hot it would keep the fan going for a few minutes after parking up. only risk i can see is it back feeding up the signal wire to the previous factory relay but its all the same voltage so it shouldnt bother it. Quote Share this post Link to post Share on other sites
antil33t 90 Report post Posted February 15, 2013 Just get the Low temp one, they are $40. from Milland. the stock one is 90/99c or something like that, low temp one is 80/88. I've got an E36 318ti fan and low temp switch on my E34, and the AC fan is still seperate. just had to snip the wire going to the low speed relay and send it to another relay for the main fan (single speed only, had a dead resistor) Quote Share this post Link to post Share on other sites
maxlatimer 0 Report post Posted July 19, 2013 Just get the Low temp one, they are $40. from Milland. the stock one is 90/99c or something like that, low temp one is 80/88. I'm currently wiring up an electric fan for my e36 323i, if I were to install a 80/88 thermo switch will I need to install a 80/88 thermostat as well so the thermostat will open at the corresponding temps? Cheers Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted July 19, 2013 I'm currently wiring up an electric fan for my e36 323i, if I were to install a 80/88 thermo switch will I need to install a 80/88 thermostat as well so the thermostat will open at the corresponding temps? Cheers no , did you get my email . they have the wiring and aux fan already in the front , if you just fit the lower temp sensor it will cut in just as the gauge goes over half Quote Share this post Link to post Share on other sites
