Cooling Fan Installation

Gotta love that wiring . . .

Moderator: So Cal Mark

cyberborikua
Posts: 32
Joined: Sat Apr 05, 2014 4:13 pm
Your car is a: 1979 Fiat Spider 2000

Cooling Fan Installation

Postby cyberborikua » Thu Apr 20, 2017 11:41 pm

Hi. Im planning on installing a new 12" cooling fan via a 4 pins relay. My plan is to hook the + of the fan motor to the 87 pin, the + of a new 87 degrees thermo switch to pin 86, an 18 gauge wire to pin 30 with an inline 40A fuse to the generator, and the negative wires of the fan and switch to ground. My question is what goes to pin 85? Not planning on using a manual switch. Thanks.

1979 Fiat Spider
Roberto

1979 Fiat Spider 2000
1970 Oldsmobile Cutlass Convertible
2005 Toyota ECHO
2007 Honda Pilot

User avatar
azruss
Posts: 3536
Joined: Sun May 30, 2010 12:24 pm
Your car is a: 80 Fiat 2000 FI

Re: Cooling Fan Installation

Postby azruss » Fri Apr 21, 2017 1:13 am

pin 85 is also a chassis ground

cyberborikua
Posts: 32
Joined: Sat Apr 05, 2014 4:13 pm
Your car is a: 1979 Fiat Spider 2000

Re: Cooling Fan Installation

Postby cyberborikua » Fri Apr 21, 2017 7:45 am

Thanks. I was not sure. 85 is the relays ground.
Roberto

1979 Fiat Spider 2000
1970 Oldsmobile Cutlass Convertible
2005 Toyota ECHO
2007 Honda Pilot

spider2081
Posts: 1952
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT
Contact:

Re: Cooling Fan Installation

Postby spider2081 » Fri Apr 21, 2017 9:24 am

Does your coolant temperature switch have 2 terminals ? One being connected to +12V and the other to terminal 86 of the relay??
The wires on terminals 85 and 86 carry only the relay coils current and #18 is more that adequate. However # 18 wire for the fans operating current on terminals 87 and 30 is too small for a 40 amp circuit. I think you need a #10 wire for a 40 amp circuit. Also what is the maximum current rating of your generator. Are you sure your generator is large enough for the additional load of this fan??
If it isn't everything in the car could be operating at a lower voltage when the fan is operating.

cyberborikua
Posts: 32
Joined: Sat Apr 05, 2014 4:13 pm
Your car is a: 1979 Fiat Spider 2000

Re: Cooling Fan Installation

Postby cyberborikua » Fri Apr 21, 2017 11:21 am

Switch has two terminals. I have the stock generator. Question: Isn't the use of a relay help with the generator load? Can I then use the coil instead?
Roberto

1979 Fiat Spider 2000
1970 Oldsmobile Cutlass Convertible
2005 Toyota ECHO
2007 Honda Pilot

rridge
Posts: 33
Joined: Thu Aug 10, 2006 11:59 am

Re: Cooling Fan Installation

Postby rridge » Fri Apr 21, 2017 3:35 pm

The original Fiat electric fans drew less than 10amps. I would check the amperage of your new 12 inch fan. Most Bosch style cube relays handle 30amps or less. If the fan is less than 20amps, 12 gauge wire would handle the load.

Size the wire and the relay to the load. Size the fuse to the wire. Don't use a 40amp fuse on a wire that can only handle 20amps.

cyberborikua
Posts: 32
Joined: Sat Apr 05, 2014 4:13 pm
Your car is a: 1979 Fiat Spider 2000

Re: Cooling Fan Installation

Postby cyberborikua » Fri Apr 21, 2017 5:20 pm

Got it! Looked at the fan and see that it is 80W. That is 6.66 amps. All the wires in my relay are 16 gauge, not 18 as previously stated. The relay is a 30/40A. So can I just put a 20A fuse on the 16 gauge wires?
Roberto

1979 Fiat Spider 2000
1970 Oldsmobile Cutlass Convertible
2005 Toyota ECHO
2007 Honda Pilot

rridge
Posts: 33
Joined: Thu Aug 10, 2006 11:59 am

Re: Cooling Fan Installation

Postby rridge » Fri Apr 21, 2017 9:26 pm

I use 10 amp fuses on 16 gage wire.


Return to “Electrical Issues”

Who is online

Users browsing this forum: No registered users and 1 guest