88 Alternator

[makoa]

22 hours ago, Jeep Driver said:

 

That's a mistake. Your cooling system needs to be mindless, build it and forget it. 

 

I'm typing this not just for you but for anyone who may read this. 

 

You are building a cooling system. E-fans get a bad rap because most people who go E-fans fail to build a cooling system which works. 

 

Each fan must have it's own relay. Wires from relays to fans should be no longer than 24".

 

I'm posting this as an example, I'm not suggesting you buy this, do your own homework- https://www.ebay.com/itm/123916172594?chn=ps&mkevt=1&mkcid=28&var=424997860739

 

That is an ON delay relay. 

You can use-

Fan 1 - standard no delay relay

Fan 2 - 5 second ON delay relay

Fan 3 - 10 second ON delay relay

 

Sender from water neck will have a neg wire. 

Neg wire to trigger main relay.

Main relay triggers three fan relays. 

You will need two standard relays and two delay relays. 

 

You have now created a sequential three fan system. 

 

Fan (1) will come on immediately upon reaching 180 degrees. 

Followed by fan (2) 5 seconds later, followed by fan (3) 10 seconds later. 

 

 

Bonus thought- 

You can piggyback the Main relay (double pole) to a second Main relay with a 3 minute OFF delay. 

When you turn the truck off the second Main relay is then triggered for three minutes to continue cooling after the engine is shut off. Eliminating heat soak. 

 

 

 

 

 

I'm gonna try to figure this out, will update when its done. All the responses have been super helpful

[Eagle]

On 8/5/2021 at 7:45 PM, makoa said:

you are correct sir

 

He's correct about what?

 

You wrote that you want to control two electric fans with the OEM wiring. The basic MJ doesn't even have an electric fan. Those that do have an electric fan, the electric fan is an auxiliary fan that doesn't turn on until the engine temperature starts to get too high. That's fine for the auxiliary fan, but that's not what I would want for controlling my primary cooling fans.

[MiNi Beast]

10 hours ago, Eagle said:

 

He's correct about what?

 

You wrote that you want to control two electric fans with the OEM wiring. The basic MJ doesn't even have an electric fan. Those that do have an electric fan, the electric fan is an auxiliary fan that doesn't turn on until the engine temperature starts to get too high. That's fine for the auxiliary fan, but that's not what I would want for controlling my primary cooling fans.

I was corrrect about the lack of wiring and that he doesn't know how to go about the problem. He needs more guidance thinking a better alt will handle his fan issues. 

[Eagle]

2 hours ago, MiNi Beast said:

I was corrrect about the lack of wiring and that he doesn't know how to go about the problem. He needs more guidance thinking a better alt will handle his fan issues. 

 

Agreed. The alternator capacity is not the most important question here.

[Jeep Driver]

The alt is just as important as-

Wiring

Fans

Radiator

Sender/switch

Battery

 

It's all important. 

 

I'm guessing- sitting in traffic on a rainy night with AC on..........

He'll tax his electrical system to about 115-125 amps.........lights, radio, amp, aux lights........whatever else he has running. 

 

He could get by with a 140 alt. 

 

The 95 amp alt will not keep up, not even close. 

 

Not to mention the one I recommended will out perform the stock alt at idle. At idle it's capable of putting out more amps than the stock is at full-tilt. 

 

There's a reason he got a rad with three fans cheap......wanna guess what that reason is?

 

Those cheap fans will draw better than 40 amps each at start up........continuous draw will be close to 25amps.

And he'll run hot anyway. 

 

Big picture.