turning on the aux fan

[C85D4x4]

Can someone tell me how to set up a switch so that i can turn on the aux fan manually?

[Gil BullyKatz]

Hmmm...


I spliced into the wires leading from the fan at a connector a few inches away from it...

Ran a switch w/relay to the cab and called it a day...

Just gotta remember to turn it on or off

[C85D4x4]

Cant i just run 2 wires from the relay it has now at the fuse box?

[Gojeep]

If you have a 91 on then they are switched on via a ground. Look at my write up on fitting duel electric fans as mention it in there.

www.go.jeep-xj.info

[Slip Kid]

There's a relay already there.

Your Jeep is what year? on the Renix there's a 2-wire connecter between the harness and the radiator switch, just splice into those two wires, and run them to a switch in the cab that connects those two wires and you're set. Newer Jeeps dont have that sensor, but there's still a relay there you could tap into, just not as easy to find the wires - I hear the newer ones just connect to ground to switch the relay, which just means you only need to run one wire.
This can be done without hindering the automatic turnon - the switch just forces it to be on when closed.

[C85D4x4]

I have a 93

Dont i need to use a fuse or something, so that i dont melt any wires.
It has a relay, and if i run 2 wires from it, cant i fry the relay?

[Warthog]

just use this, takes all the time and guesswork out of it.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7966770911&category=33600

[xjj33p3r]

That's really conveniant, but $35 is a bit over-priced for 10 bucks worth of materials, don't you think?

[C85D4x4]

Yes

But i am talking about the relay that i have now, that is in the fuse box, under the hood.

Cant i just take 2 wires and connect them to where that relay is and connect them to a switch?

[Warthog]

That's really conveniant, but $35 is a bit over-priced for 10 bucks worth of materials, don't you think?

hey time is money.......i got this unit and it took 15-20 min. to install,
no trouble shooting, no fried relays. the instructions are easy to follow.

if you're a do-it-yourself, please by all means go for it. if your a plug-play person here is cool unit.

[Eagle]

Never mind. Redundant.

Sorry

[C85D4x4]

But i am talking about the relay that i have now, that is in the fuse box, under the hood.

Cant i just take 2 wires and connect them to where that relay is and connect them to a switch?

Does anyone know if this would work?

[XJZ]

Whatever you do, don't invert the wires at the fan-it'll blow outwards.

Couldn't figure out why my fancy manual fan wasn't helping with the cooling. :dunce:

Oh well.

[outlander]

just use this, takes all the time and guesswork out of it.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7966770911&category=33600
cool,I think I'll get one

[C85D4x4]

Ill try not to do that.

Anyone else?

[Planetcat]

I did the splicing thing. Works great, $15 worth of materials. 4-prong relay mounted near battery: prong 30 to battery (+) w/30 amp fusible link, prong 85 grounded to frame, prong 87 to fan splicing connector on (+) white wire on aux fan, and prong 86 to toggle switch. Ground toggle to metal under dash, run toggle (+) to under dash light (+) wire for lighted toggles and you're done. Best thing about it is you don't have to cut any existing wires. Fan goes on via ecu or manually via switch.

[C85D4x4]

I did the splicing thing. Works great, $15 worth of materials. 4-prong relay mounted near battery: prong 30 to battery (+) w/30 amp fusible link, prong 85 grounded to frame, prong 87 to fan splicing connector on (+) white wire on aux fan, and prong 86 to toggle switch. Ground toggle to metal under dash, run toggle (+) to under dash light (+) wire for lighted toggles and you're done. Best thing about it is you don't have to cut any existing wires. Fan goes on via ecu or manually via switch.
Ok i understand what ur saying,
but just not the "prong 30, prong 85, prong 87, prong 86"

What these?

[Planetcat]

I'm lame when it comes to electrical and can't understand how a relay works to save my life, yet have installed many of them on vehicles for lighting, fans, etc. On most of the relays, pep boys, kragen, bosch, etc. the prongs on the relay are stamped with numbers so you know which wire to hook to which prong on the relay. Some even have little relay switch diagrams stamped on them that you can use for reference if you understand how they work. Most of the wiring kit relays have them numbered too to correspond with the directions for installation.

[C85D4x4]

What relay did you use?

Or are all the numbers on the prongs the same on all relays?

[Timber]

What relay did you use?

Or are all the numbers on the prongs the same on all relays?
12v relays have been standardized. The poles (prongs) referred to are usually stamped on all but the worst-quality ones. The only thing to watch for is a "dual-output" relay. This will have an additional #87, labeled 87A. Don't bother getting this type; they're a bit more expensive and unnecessary for this project.

[Dingo509]

12v relays have been standardized. The poles (prongs) referred to are usually stamped on all but the worst-quality ones. The only thing to watch for is a "dual-output" relay. This will have an additional #87, labeled 87A. Don't bother getting this type; they're a bit more expensive and unnecessary for this project.

Not all relays with a 87a treminal are dual output, there is also a "change over" relay which uses either the 87 or 87a terminal depending if the coil is energized or not, and those can be found in normally open or normally closed variants as well.

Now that ive confused you Timber is right about just buying the one with only 1 87 terminal.

Dingo