radiator fan switch modification
11-12-02, 07:25 PM
#1
2/4 wheel cornering fiend
Thread Starter
radiator fan switch modification
In performing the radiator fan switch modification (tapping into the rad fan switch relays to activate the fans remotely while stuck in traffic, etc.) on my '93 touring, I found that the wiring setup for the "medium speed" configuration doesn't work. I'm able to activate the fans on "low speed", but when I ground the relay combo for medium, it only works when the engine is off. All it does when the engine is running is activate the 10-minute fan sequence when the engine is shut off, even though the coolant temps are far below what would normally trigger the sequence. In checking the wiring diagram, it appears that the modification also grounds the temp sensor, which could possibly trigger the sequence. Yet I've talked to other FD3S owners who haven't had a problem performing this modification on the "medium speed" setting. Does anyone have any experience with the electrical setup on an FD3S to offer an explanation/solution? (yes, I know that activating the A/C runs the fans on medium/high speed, but I'd rather not have the unnecessary drag on the motor if possible)
Also, I discovered that the driver's side radiator fan has died. I was told by TriPoint Engineering that this is a fairly common occurrence. Anyone else had this problem? I'm loathe to have to spend the $$$ for a new fan motor...
Kto
Also, I discovered that the driver's side radiator fan has died. I was told by TriPoint Engineering that this is a fairly common occurrence. Anyone else had this problem? I'm loathe to have to spend the $$$ for a new fan motor...
Kto
11-12-02, 08:01 PM
#2
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If you are just grounding the wire to make the fan come on at medium speed correctly (both grounds) then I suggest check your relay housing.... my money is its all burned up.
There was a thread on that a while back... I can't find it though.
There was a thread on that a while back... I can't find it though.
11-12-02, 08:11 PM
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11-12-02, 10:46 PM
#4
Do you know about?
You mentioned the 10 minute cooling fan run so you may know this, but:
http://www.scuderiaciriani.com/rx7/fan_mod.html
In short, ground an existing and unused test wire next to the ECU 2 minutes before shutdown. The fans come on medium. Run the car until it's as cool as you want. Shut down. Un-ground the wire and the fans shut off OR leave it grounded for 30 seconds. The fans run for 10 minutes on low.
The mod that you are going after will give you an immediate on / off, but this mod is far simpler to do and works great.
It's especially useful when shutting down a hot engine during the blistering summer days here in LA, CA.
http://www.scuderiaciriani.com/rx7/fan_mod.html
In short, ground an existing and unused test wire next to the ECU 2 minutes before shutdown. The fans come on medium. Run the car until it's as cool as you want. Shut down. Un-ground the wire and the fans shut off OR leave it grounded for 30 seconds. The fans run for 10 minutes on low.
The mod that you are going after will give you an immediate on / off, but this mod is far simpler to do and works great.
It's especially useful when shutting down a hot engine during the blistering summer days here in LA, CA.
11-12-02, 10:54 PM
#5
don't race, don't need to
How weird is THAT? I just did the mod you are speaking of, where I ground the black with green wire for low speed (relays 2 and 4) whether the car is on or off. Whan I ground the violet with pink wire on relay 1, I only get the fan on med if the ignition is set to run. This makes sense according to the circuit diagram. So your med speed only comes on with the car OFF!!?? Specifically, which relays did you set up to be grounded?
BTW, LOVE LOVE LOVE the fan mod. Though it does heat up the air box and IC a little
BTW, LOVE LOVE LOVE the fan mod. Though it does heat up the air box and IC a little
11-13-02, 12:03 AM
#6
I pulled my air conditioning relay out of the socket. I rarely use the A/C so it is not really a sacrifice for me. With this relay pulled, I am able to turn on my A/C, have the fans come on, but keep the compressor from compressing. I usually use it at shut down and any idle time that the car sees. Good luck.
Kyle
Kyle
11-13-02, 03:30 PM
#7
2/4 wheel cornering fiend
Thread Starter
Thanx for your suggestions everyone.
"Spurvo": the relays I grounded are exactly the same as you specified in your post. And yet I'm getting an entirely different result.
"Twifosp": Thankfully, the relays are in good working order (plus, if they were burnt up, the fans would not come on at all, no?). But after reading the thread you forwarded on the posts arcing and burning up, I shall keep a close eye on them.
"James Paventi": Yes, I did know of the "original" fan switch mod, but I preferred this one due to its convenience (not required to remember to activate two minutes before shutdown, then waiting 30 seconds to activate 10-minute sequence). However, I may reconsider reverting to the original mod in the future. My only concern is that it does heat up the I/C more than it already gets from heat soak within the engine compartment after shutdown, which is a slight concern in city driving. I had Tripoint install a small SPAL fan on my Greddy SM intercooler specifically for the heat soak at slow speed problem, but IMO it doesn't force enough air through to make a major difference.
Kto
"Spurvo": the relays I grounded are exactly the same as you specified in your post. And yet I'm getting an entirely different result.
"Twifosp": Thankfully, the relays are in good working order (plus, if they were burnt up, the fans would not come on at all, no?). But after reading the thread you forwarded on the posts arcing and burning up, I shall keep a close eye on them.
"James Paventi": Yes, I did know of the "original" fan switch mod, but I preferred this one due to its convenience (not required to remember to activate two minutes before shutdown, then waiting 30 seconds to activate 10-minute sequence). However, I may reconsider reverting to the original mod in the future. My only concern is that it does heat up the I/C more than it already gets from heat soak within the engine compartment after shutdown, which is a slight concern in city driving. I had Tripoint install a small SPAL fan on my Greddy SM intercooler specifically for the heat soak at slow speed problem, but IMO it doesn't force enough air through to make a major difference.
Kto
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