2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Elec. Fan retrofit- EXCELLENT REFERENCE!!

Thread Tools
 
Search this Thread
 
Old 09-11-03, 05:20 PM
  #1  
Driving RX7's since 1979

Thread Starter
iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Likes: 0
Received 8 Likes on 8 Posts
Elec. Fan retrofit- EXCELLENT REFERENCE!!

For all those looking to replace your mechanical clutch radiator fan with a wrecking yard electrical fan, this is an excellent how-to so install is as factory like as can be.

http://www.s-seriesforum.com/section...ntpage&artid=1
Old 09-11-03, 05:40 PM
  #2  
Like Ghandi with a gun

 
Kenteth's Avatar
 
Join Date: Mar 2003
Location: Rapid City, SD
Posts: 4,584
Likes: 0
Received 0 Likes on 0 Posts
seeing the pictures of those relay diagrams just makes me smile for some reason
Old 09-11-03, 11:33 PM
  #3  
SOLD THE RX-7!

 
Scott 89t2's Avatar
 
Join Date: Mar 2001
Location: Vancouver, BC, Canada
Posts: 7,451
Likes: 0
Received 0 Likes on 0 Posts
I don't uderstand why he has 2 relays ??? unless he plans to put more then 30 amps to the fan which I highly doubt.

or maybe as backup if one failed.
Old 09-12-03, 12:02 AM
  #4  
Driving RX7's since 1979

Thread Starter
iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Likes: 0
Received 8 Likes on 8 Posts
Why two relays

"The double relays are necessary unless you have a fan that uses less than 30 amps"

I believe the Taurus the fan came from calls for a dedicated 50 amp fuse. Thus, two 30 amp relays.

The thermo switch can only handle 16 amps by itself. So certainly a relay will be needed if you want an as needed fan.
Old 09-12-03, 12:08 AM
  #5  
Driving RX7's since 1979

Thread Starter
iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Likes: 0
Received 8 Likes on 8 Posts
administrator, please delete this...

ooppss

Last edited by HOZZMANRX7; 09-12-03 at 12:13 AM.
Old 09-12-03, 12:08 AM
  #6  
Driving RX7's since 1979

Thread Starter
iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Likes: 0
Received 8 Likes on 8 Posts
Administrator, please delete this....

ooppss

I couldn't get the delete button to work for me.

Thanks

Last edited by HOZZMANRX7; 09-12-03 at 12:14 AM.
Old 09-12-03, 12:13 AM
  #7  
Super Raterhater

iTrader: (6)
 
SonicRaT's Avatar
 
Join Date: Dec 2001
Location: NY, MA, MI, OR, TX, and now LA or AZ!
Posts: 10,624
Likes: 0
Received 2 Likes on 2 Posts
Why not just get a 45amp relay or higher? That's what I'm using
Old 09-12-03, 02:00 AM
  #8  
Senior Member

 
Tripple 7's's Avatar
 
Join Date: Jun 2003
Location: Tempe, AZ
Posts: 306
Received 20 Likes on 14 Posts
2 small relays do not equal one large one




That install sucks to be honest with you.

Especially the scotch lock, these should never be used on a vehicle as they are vibration prone, they are also refered to as "short locks" as to their problematic tendancy.


Old 09-12-03, 10:11 AM
  #9  
Rotors still spinning

iTrader: (1)
 
rotarygod's Avatar
 
Join Date: Jul 2002
Location: Houston
Posts: 4,181
Likes: 0
Received 19 Likes on 13 Posts
Scotchlocks, T-taps, whatever you call them, yes they definitely suck. Such little area for runnng current through. I'd be terrified to run anything that draws 30 amps through them. 2 small fuses equals 1 big one. Why not 2 relays?
Old 09-12-03, 10:46 AM
  #10  
Despise Enmity

 
Josepi's Avatar
 
Join Date: May 2001
Location: Richmond, VA
Posts: 2,420
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by rotarygod
Scotchlocks, T-taps, whatever you call them, yes they definitely suck. Such little area for runnng current through. I'd be terrified to run anything that draws 30 amps through them. 2 small fuses equals 1 big one. Why not 2 relays?
The ones I had couldn't even break through 14 gauge wire using pliers...
Old 09-12-03, 10:56 AM
  #11  
In Full Autist Cosplay

iTrader: (1)
 
Black13B's Avatar
 
Join Date: Nov 2002
Location: Alberta
Posts: 2,330
Likes: 0
Received 0 Likes on 0 Posts
Scotchlocks are bad.

I know it's been stated above, but we need some serious emphasis on that.
Old 09-12-03, 03:01 PM
  #12  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
The person who wrote that seems to be lacking some very basic electronics knowledge. Specifically. paralleling two relays. This does not double the current they can carry. Why? Well, because both relays don't turn on and off at the same time. This is when the wear occurs. An arc is created when a relay makes or breaks contact. Because you have to mechanical arms moving, there is some variation and one will almost always turn on/off before the other. This means that it bears the full load of the current draw, and thus draws a fairly decent sized arc. This pits contacts, causes carbon build up, etc. Using 1 relay that can handle the current would have been the proper thing to do.

FWIW, I have a writeup like this targeted toward the FC owner that will be posted when I update my website. It is fairly detailed, with proper schematics, etc. But it won't be up for months.
Old 09-12-03, 04:04 PM
  #13  
Seduced by the DARK SIDE

 
SureShot's Avatar
 
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes on 2 Posts
I use 2 relays, but one is to ground the AWS solenoid.
I put a plug in the AWS hose with a 1/16” hole, so that when the fan comes on, the alternator doesn't stall the engine.
Old 09-20-03, 01:29 PM
  #14  
Driving RX7's since 1979

Thread Starter
iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Likes: 0
Received 8 Likes on 8 Posts
Question Higher amperage relay

Typical Bosh type relays are designed for 30 amps. Where would one get a relay designed to handle 45-60 amps that is also designed to withstand the heat and stress's of being in an engine bay?
Old 04-22-04, 03:15 PM
  #15  
Senior Member

 
surfpac's Avatar
 
Join Date: Nov 2001
Location: Pembroke Pines, FL
Posts: 354
Likes: 0
Received 1 Like on 1 Post
Re: Higher amperage relay

Originally posted by HOZZMANRX7
Typical Bosh type relays are designed for 30 amps. Where would one get a relay designed to handle 45-60 amps that is also designed to withstand the heat and stress's of being in an engine bay?
This outa do the trick
http://www.partsamerica.com/PartDeta...pe=575&PTSet=A

or Bosch part#0 332 002 156
from here http://www.bpg-inc.com/bpghome.html

Last edited by surfpac; 04-22-04 at 03:30 PM.
Old 04-25-04, 05:57 PM
  #16  
Senior Member

 
jhillyer's Avatar
 
Join Date: Oct 2002
Location: San Ramon CA 94583
Posts: 307
Likes: 0
Received 0 Likes on 0 Posts
Vouching

Originally posted by Aaron Cake
The person who wrote that seems to be lacking some very basic electronics knowledge. Specifically. paralleling two relays. This does not double the current they can carry. Why? Well, because both relays don't turn on and off at the same time. This is when the wear occurs. An arc is created when a relay makes or breaks contact. Because you have to mechanical arms moving, there is some variation and one will almost always turn on/off before the other. This means that it bears the full load of the current draw, and thus draws a fairly decent sized arc. This pits contacts, causes carbon build up, etc. Using 1 relay that can handle the current would have been the proper thing to do.

FWIW, I have a writeup like this targeted toward the FC owner that will be posted when I update my website. It is fairly detailed, with proper schematics, etc. But it won't be up for months.
I agree that paralleling two contacts each at 50% of duty is inadequate. However, we can dampen the current transient with a choke and capacitor for reactance. Impeding the load spike inline with a coil, and shunting the spike to ground with a capacitor is good for increasing life of a switched system, but adding enough dampening to allow for for wide variations in relay switching times approaches the cost of a properly rated relay.

Anyone have data about how this electrical load affects ignition performance?
Old 04-25-04, 06:01 PM
  #17  
Rotary Enthusiast

 
RylAssassin's Avatar
 
Join Date: May 2002
Location: Boston
Posts: 1,203
Likes: 0
Received 0 Likes on 0 Posts
Wait what the hell is going on? Theres no pic of the e-fan...What e-fan did he use>??
Old 04-26-04, 12:39 PM
  #18  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
Re: Vouching

Originally posted by jhillyer
[B]I agree that paralleling two contacts each at 50% of duty is inadequate. However, we can dampen the current transient with a choke and capacitor for reactance. Impeding the load spike inline with a coil, and shunting the spike to ground with a capacitor is good for increasing life of a switched system, but adding enough dampening to allow for for wide variations in relay switching times approaches the cost of a properly rated relay.
Exactly. Why would you do this when a properly sized relay is most certainly cheaper then a (high current) choke coil and decently rated capacitor?

BTW, my writeup, for anyone who cares, is now at http://www.aaroncake.net/rx-7/efaninstall.htm
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Blastfastrotary
2nd Generation Specific (1986-1992)
6
09-11-15 12:26 AM



Quick Reply: Elec. Fan retrofit- EXCELLENT REFERENCE!!



All times are GMT -5. The time now is 04:44 AM.