I was wondering if anyone has altered the engine room cooling fan to run constantly when the engine is running? If you have done this, please let me know how you achieved this.
Thank you very much!
Trev
Thank you very much!
Trev
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Engine room cooling fan-how-Want on with ignition!
- Thread starter ffffanman
- Start date
I have not heard of anyone changing the engine bay cooling fan operation. Just for your information Honda stopped installing engine bay cooling fans in later NSX's all together.
Briank said:
mine was never on. when does it turn on anyway?
It goes on when the coolant temp reaches 194F - 90C
When its on its on!
From what I can see in the o&m, this fan comes on only when the radiator cooling fan is told to turn to high. So your car has to be pretty hot! There is a blue/red wire coming out of the cooling fan control box that goes to both relays, that is the high cooling fan relay and the relay for the engine bay cooling fan. From the ignition switch is a yellow black wire that comes to the other side of the EBCF relay. Coming out of the EBCF is a white/blue that goes to the EBCF motor. I see different other wires in the manual that say they are going to the EBCF so I'm confused right now.
I have mainfuse box no. 24 10amp white/green going to the EBCF.
I have dash fuse box no. 4 15 amp yellow/black going to the EBCF.
Page 2 of the wiring diagrams right at the back of the manual had that no.4 as a no.2 with 120 amps!!!
My eyes are tired so I might be silly here.
One thing that bothers me about monkeying around here is that that blue red that runs from the cooling fan control also goes to the FI-ECU - 14c.
Id hate to blow up my car!!!
I just wanted to do a McGiver with some silver foil from a wrigleys gum wrapper and make this fan run when my ign. is on.
Ill just leave it alone now and walk away!
Trev
From what I can see in the o&m, this fan comes on only when the radiator cooling fan is told to turn to high. So your car has to be pretty hot! There is a blue/red wire coming out of the cooling fan control box that goes to both relays, that is the high cooling fan relay and the relay for the engine bay cooling fan. From the ignition switch is a yellow black wire that comes to the other side of the EBCF relay. Coming out of the EBCF is a white/blue that goes to the EBCF motor. I see different other wires in the manual that say they are going to the EBCF so I'm confused right now.
I have mainfuse box no. 24 10amp white/green going to the EBCF.
I have dash fuse box no. 4 15 amp yellow/black going to the EBCF.
Page 2 of the wiring diagrams right at the back of the manual had that no.4 as a no.2 with 120 amps!!!
My eyes are tired so I might be silly here.
One thing that bothers me about monkeying around here is that that blue red that runs from the cooling fan control also goes to the FI-ECU - 14c.
Id hate to blow up my car!!!
I just wanted to do a McGiver with some silver foil from a wrigleys gum wrapper and make this fan run when my ign. is on.
Ill just leave it alone now and walk away!
Trev
I've only seen the engine fan run once. On a mountain drive on a hot day, our group pulled off to the side and we heard a fan running from one of the cars. Popped the engine cover and there it was, actually working!
In HK where the temp. in the summer is over 30 c,even in stop and go driving with the a/c on full, i have yet to see this fan on. I would not change this at all and there is a reason in early production to instal such. Honda is very cautious of the NSx and would built in such, in case !!!
What year did they stop installing them?Briank said:
I actually pulled mine years ago; It was not necessary on our NA engines. However, with my SC the ambient air temp in the compartment is now substantial. I am going to put it back and have it turn on with ignition. May not help, but cannot hurt.
Alternatively, I may use it to augment flow across an oil cooler mounted in the right fender well.
So, back to the orginal question...where is the easiest place to tap the fan wiring into so that it turns on with ignition?
Rear fuse box or does anyone know a wire in the adjacent engine harness?
By the way....does it blow out into the fender or pull in to the engine?
Alternatively, I may use it to augment flow across an oil cooler mounted in the right fender well.
So, back to the orginal question...where is the easiest place to tap the fan wiring into so that it turns on with ignition?
Rear fuse box or does anyone know a wire in the adjacent engine harness?
By the way....does it blow out into the fender or pull in to the engine?
It pulls in.
I would probably recommend having a seperate switch rather than permanently on whenever the ignition is on.
You will need to break into the harness feeding the engine fan relay that is located just rear of fan itself.
See location of the correct connector/harness at
http://www.nsxprime.com/FAQ/Reference/1991_svcman/1991servman.pdf
page 1000; and also in the pics in the subsequent posts.
The electrical schematic is on pages 1100/1101.
(just type the page number [enter] in the field at the bottom that indicates page 1 of 1420)
Disconnect the plug feeding that connector under the relay:
Find the blue/red wire located in the harness that you have just unplugged then cut it (make sure you give yourself enough wire to work with i.e. don't cut it too close to the connector!).
Take the cut end that goes to the connector end itself (as opposed to the one going back into the harness), and splice a wire to it, from which you will connect it via a switch to ground.
(I would just splice a wire to that blue/red one & run a wire into the interior compartment & mount switch somewhere conveniently for the driver - on the switch, connect this new wire to one terminal, then connect a wire from a convenient chassis ground location to the other terminal)
Plug the connector back in & check it out.
If you don't want to mess with the cabin switch, simply connect an extension wire this same blu/red wire (feeding the plug end) directly to chassis ground. Then it will operate continuously with ignition on.
Incidentally the "open" end of the blue/red wire you cut, will continue to have the o/p from the fan control unit feed the radiator high-speed fan & the ECU without inteference from the engine fan unit itself, or to your new ground switch and associated wiring. Just make sure you actually cut the wire - don't simply splice a wire onto there with a wire tap.
Note: Make sure you get the correct wire - there are essentially 4 wires feeding that relay connector; It gets confusing here in my manual because the colors don't agree in the two reference schematics;
one (page 1000) says the 4 wires are yel/blu; blk/yel; wht/red; wht/blu. THESE ARE WRONGLY IDENTIFIED - I physically checked them.
The other (pages 1100/1101) shows blu/red; yel/blk; white/grn; wht/blu. THESE COLOURS ARE THE CORRECT ONES
The blu/red one is the one you want: It supplies a ground to the coil of the engine fan relay;
If you really wanted to get sophisticated, you could also cut the yel/blk wire & splice it to the acc cct, rather than ignition - this would allow you to turn off the engine, but still have the fan run with the ign switch in acc position.
You will need to break into the harness feeding the engine fan relay that is located just rear of fan itself.
See location of the correct connector/harness at
http://www.nsxprime.com/FAQ/Reference/1991_svcman/1991servman.pdf
page 1000; and also in the pics in the subsequent posts.
The electrical schematic is on pages 1100/1101.
(just type the page number [enter] in the field at the bottom that indicates page 1 of 1420)
Disconnect the plug feeding that connector under the relay:
Find the blue/red wire located in the harness that you have just unplugged then cut it (make sure you give yourself enough wire to work with i.e. don't cut it too close to the connector!).
Take the cut end that goes to the connector end itself (as opposed to the one going back into the harness), and splice a wire to it, from which you will connect it via a switch to ground.
(I would just splice a wire to that blue/red one & run a wire into the interior compartment & mount switch somewhere conveniently for the driver - on the switch, connect this new wire to one terminal, then connect a wire from a convenient chassis ground location to the other terminal)
Plug the connector back in & check it out.
If you don't want to mess with the cabin switch, simply connect an extension wire this same blu/red wire (feeding the plug end) directly to chassis ground. Then it will operate continuously with ignition on.
Incidentally the "open" end of the blue/red wire you cut, will continue to have the o/p from the fan control unit feed the radiator high-speed fan & the ECU without inteference from the engine fan unit itself, or to your new ground switch and associated wiring. Just make sure you actually cut the wire - don't simply splice a wire onto there with a wire tap.
Note: Make sure you get the correct wire - there are essentially 4 wires feeding that relay connector; It gets confusing here in my manual because the colors don't agree in the two reference schematics;
one (page 1000) says the 4 wires are yel/blu; blk/yel; wht/red; wht/blu. THESE ARE WRONGLY IDENTIFIED - I physically checked them.
The other (pages 1100/1101) shows blu/red; yel/blk; white/grn; wht/blu. THESE COLOURS ARE THE CORRECT ONES
The blu/red one is the one you want: It supplies a ground to the coil of the engine fan relay;
If you really wanted to get sophisticated, you could also cut the yel/blk wire & splice it to the acc cct, rather than ignition - this would allow you to turn off the engine, but still have the fan run with the ign switch in acc position.
Last edited:
D'Ecosse,
OUTSTANDING...thanks!
OUTSTANDING...thanks!
Thanks so much!
Thanks a bunch dude!
Trev
Thanks a bunch dude!
Trev
