Cooling fan wiring question
Thread Starter
|
Postmaster
Joined: Aug 2001
Posts: 2,882
Likes: 0
From: Nevada
Cooling fan wiring question
I'm wiring multiple cooling fans and Sumitt sent me two relay wiring harnesses, one by BeCool and one by Spal. The BeCool harness has the fuse in the power wire between the fan and the relay while Spal has it in the battery power wire between the battery and relay. Which is correct or preferred? I can change either harness.
Thanks in advance for any advice and recommendations.
Thanks in advance for any advice and recommendations.
Post Fiend
Joined: Sep 2000
Posts: 8,238
Likes: 3
From: Oregon
Most have the fuse between the main relay and the electrical unit. The alternator connects to the relay to charge the battery, and if the fuse was between the battery and the relay it would shield the battery from an alternator surge but not the electrical unit. You are talking about, I assume, an auxillary relay for your fans. This being the case I would put the fuse before the relay, to head off any spikes coming down from the main relay. Either of your harnesses could be considered "correct", its merely preference. Its only a switch, but you might as well head off any meltdowns when you can. Thats how I have mine wired up. Basically I have all my fuses AFTER my primary relay (solenoid) but BEFORE my auxillary relays.
Last edited by proeliator; Oct 4, 2003 at 10:03 AM.
Thread Starter
|
Postmaster
Joined: Aug 2001
Posts: 2,882
Likes: 0
From: Nevada
I've converted to a one-wire aftermarket alternator and mini high tork starter with a self contained solenoid, so this will be a direct connection to the battery with a power block to feed the fans. I got rid of the solenoid and external regulator on the fender.
I agree the protection should be before the circuit and relay and will convert the BeCool relay to that. Should I use a circuit breaker in the battery feed wire before the power distribution block for extra insurance? Was this BeCool's assumption when wiring the fuse after the relay?
Thanks for the response.
I agree the protection should be before the circuit and relay and will convert the BeCool relay to that. Should I use a circuit breaker in the battery feed wire before the power distribution block for extra insurance? Was this BeCool's assumption when wiring the fuse after the relay?
Thanks for the response.
Posting Guru
Joined: Jun 1999
Posts: 2,007
Likes: 0
From: Oregon
It's always a good idea to have a fuse close to the battery to protect your distribution block and wiring, so if something shorts in the system anywhere, things can be protected. It's also a good idea to have a fuse between the relay and the fan. If the fan were to ever short, the fuse would protect your relay from surpassing it's current rating. Your battery doesn't push current out to your fan, your fan pulls current from the battery. In the event of a short at the fan, (or the B+ wire touching ground someplace), the battery just see's a huge load and will deliever untill it's dead or till the power wires burn up and melt. When your fuse blows, it's just cutting off the current drain.
If you were to put a fuse to each of your fans, if one fan had a problem it would blow it's own fuse and the other fan or fans would continue to work. And if a major short happened at the distribution block, the fuse at the battery would protect your wiring to the battery.
If you were to put a fuse to each of your fans, if one fan had a problem it would blow it's own fuse and the other fan or fans would continue to work. And if a major short happened at the distribution block, the fuse at the battery would protect your wiring to the battery.
Thread Starter
|
Postmaster
Joined: Aug 2001
Posts: 2,882
Likes: 0
From: Nevada
Using an average maximum start-up draw of 20a per fan (each fan is rated at 1500cfm and I'll check the draw at installation to be certain) and another accessory rated at 15a in the distribution block means an 80a circuit breaker (or more?) between the battery and distribution block. Then run the power wire from the distribution block directly to the relay. Power from the relay should then be fused between each relay and fan. Do I have it right?
What about the ignition wires from the relay? Is there enough draw there that I should I use a distribution block and fuse it between the ignition and distribution block? Or do it for the sake of convenience.
I really appreciate the help, and after your help and looking at what was done to a stero in another vehicle, I do intend to have a serious talk with the installer.
What about the ignition wires from the relay? Is there enough draw there that I should I use a distribution block and fuse it between the ignition and distribution block? Or do it for the sake of convenience.
I really appreciate the help, and after your help and looking at what was done to a stero in another vehicle, I do intend to have a serious talk with the installer.
