robgti 0 Posted April 7, 2007 hi all ive managed to wire in my fans so that they run off a relay and switch but it keeps popping fuses. is it because im running twin fans instead of just the one so they for pulling more current than one? ive tried a 25amp and 30 amp fuse and it just pops them. any ideas? Share this post Link to post Share on other sites
robgti 0 Posted April 7, 2007 ok ive been doing a search and think it will be best to run one of the fans off a switch instead of the two as this is overloading the fuse. maybe i could make up another wiring loom with another relay the same and have the two running off two seperate switchs so that there isnt as much current running through one wiring loom if that makes sense? Share this post Link to post Share on other sites
Ryan 99 Posted April 7, 2007 Cars with twin fans as standard have a 25amp fuse for each fan, so I guess one 25/30 amp isn't enough? Share this post Link to post Share on other sites
robgti 0 Posted April 7, 2007 thats what i thought. think i will just disconnect one of the fans for now and see if it will run ok until i sort something out for the other one. cheers Share this post Link to post Share on other sites
Mikey G 3 Posted April 7, 2007 You could run 2 relays off one switch as the trigger current is minimal, but both relays would need seperate fuses. Or you could run both fans through a bigger fuse and relay like this one http://www.autoelectricsupplies.co.uk/product/171 I would keep the seperate relays and fuses so if one fails you still have the other. Share this post Link to post Share on other sites
robgti 0 Posted April 7, 2007 where would i get a fuse big enough to make this relay? ive seen the strip fuse which go up to 100 amp will these be ok to use? ( i know 100 amp is abit too much but 60 or 80 will be used) Share this post Link to post Share on other sites
Mikey G 3 Posted April 7, 2007 Yes it would need to be a bigger fuse, not like the standard blade type. Strip fuse would be a pain if it keeps blowing. You could run a trip although a little more expensive ---> http://www.autoelectricsupplies.co.uk/product/286 Share this post Link to post Share on other sites
robgti 0 Posted April 7, 2007 ok i think im going to go down the two relays to one switch way. just ordered myself the same wire and relay that im already using so hopefully will get this sorted. will a 30amp switch be ok to use with two relays? Share this post Link to post Share on other sites
Mikey G 3 Posted April 7, 2007 The switch to operate the relay would only need to be small. The amperage to trigger a relay is small, much less than an amp. That is the whole idea of using relays is to take the current away from a switch. Make sure the cable through the load side of the relay is greater than the amps you intend to run, then choose a fuse slightly smaller than that e.g. 30 amp cable would need a 25 amp fuse. To be honest 25 amps seems about right for a fan if not a bit big. Maybe get hold of a cheap amp gauge you can wire in temporarily to see what they are pulling then find a fuse size more suitable. Share this post Link to post Share on other sites
robgti 0 Posted April 8, 2007 ok thanks for the advice. ive been out this morning and disconnected one of the fans, put a 25amp fuse in and it works great cheers. Share this post Link to post Share on other sites
