My daughter has a stock 2001 is300 (we have four total, one for each sibling). The fans do not come on with the A/C, but do run when I jump the electrical plug at the bottom of the radiator. I just replaced the coolant sensor at the bottom of the radiator. Which relays control the fans - I believe there are three but I’m not sure which ones they are.
Thanks in advance for any help!
Not too sure, but I'd get a multimeter and probe from the fuse box to the fans. I believe every fan fuse is under the hood, which box they're in I don't remember if it's the one by the battery or by the driver headlight. Both fan plugs are right I front of the power steering pump, which is the black reservoir on the intake side of the motor. Might just be a bad relay, they do have a lifespan. Best of luck to you.
On mine it is the panel on the passenger side of the engine bay (i think drivers side for you), there are 3 relays that look the same. For the fan low speed fan and high speed relay, from memory the 3rd relay is for the horn or something else and can be swapped for one of the fan ones but not the other. It is labelled under the plastic cover.
I found the three fan relays in the driver’s side box. The fourth relay is for the A/C compressor, which is the same relay as fan number 1 and fan number 3. I have very little experience (ok, I have no experience) with 12v electrical systems but I energized all three relays and the other two prongs on each relay had continuity. Fan number 2 relay has 5 prongs (the three others have 4), with one of the copper looking prongs between the two silver prongs which is hot and ground. I had continuity between the two copper looking prongs at the opposite end from the silver prongs, but I had no continuity between the one in between the silver prongs and either of the other copper looking ones.
Should I set the multi meter to a setting to have a reading for the amount of energy between the copper looking prongs when energized?
Thanks for your help.
My daughter has a stock 2001 is300 (we have four total, one for each sibling). The fans do not come on with the A/C, but do run when I jump the electrical plug at the bottom of the radiator. I just replaced the coolant sensor at the bottom of the radiator. Which relays control the fans - I believe there are three but I’m not sure which ones they are.
Thanks in advance for any help!
To be honest i am not 100% sure either as i am no electrical expert either, when I was checking mine I swapped them around with some spare ones and with the others to see if it made any difference. If you can figure out which ones are the low current you could try switching them and then measure the continuity of the other 2 to see if they are ok.
If they all seem to be working the next thing is to check the fuses, or the AC console in the car.
Do the fans come on for normal engine cooling in traffic? If so then I doubt it is the relays, more likely AC console or fuse.
The fans do not turn on under any conditions. I will check into the AC console and fuses. Thanks
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Lexus IS Forum
5.5M posts
129.7K members
Since 2000
Community dedicated to Lexus IS Enthusiasts. Come in and enjoy our articles, galleries and information on aftermarket parts for the IS300, IS250, IS350.