fans dont activate by themselves
Thread Starter
Full Member
Joined: May 2007
Posts: 56
Likes: 1
From: Canada
fans dont activate by themselves
i'm having an issue here with my FD. i know the AC fans are supposed to turn on by themselves to cool the car but mine never do. I have to manually turn the AC on for them to fire up. never thought this would be the way they operate but is it and how can I fix this? 
When the relays come on:
- Relays 2 & 4 controlled by PCME, come on when temp reaches 221F.
- Relay 3 controlled by thermoswitch, comes on at 226F
- Relay 1 controlled by A/C switch.
- Off, none on
- Low speed comes on when relays 2 & 4 are active.
- Med speed comes on when 2 & 4 are on plus either 3 or 1 comes on but not both
- High speed comes on when all are on.
- The fan controller can bypass the 226 thermoswitch and fake out the relays 2 & 4.
- Grounding the test lead _immediately_ turns on relay 3.
- When you ground the test lead then the fan controller waits 2 min and turns on 2 & 4.
- If the test lead grounded for 2 minutes before engine shutoff, relays 2,3,4 will be kept on.
put the key to the on position, in the diagnostic box jump the TFT and GND together. you should hear the relays (pass side by the strut tower) click. that will test if they actually work or not... do that and post up.. or pm me you number and i can help walk you through testing it
Thread Starter
Full Member
Joined: May 2007
Posts: 56
Likes: 1
From: Canada
Unless you have something to turn the fans on sooner, the stock ECU will not trigger them to come on until 221F:
http://www.fd3s.net/fan_mod.html
http://www.fd3s.net/fan_mod.html
