alternator swap?

[jerzeydevll]

hey everybody im looking into putting dual electric fans in my yj because my clutch fan is bent and wobbly, and im also rebuilding a ramsey winch, so i feel i might want a new alternator that will put out alittle bit more amps, does anyone have an opinion on this ? and if it is a good idea will i need any new wiring ? and what would be a good alternator to choose ?

 

[jfrabat]

I swapped mine out a while back (8 years ago?). Ended up unsing a load boss... 160A or so IIRC. It is still in the Jeep, and running strong.

 

[69jeepcj]

I have to do the same thing. I put a tarus efan in my jeep about a week ago and it is pulling too much from my alt, im blowing fuses and volts is only 11.5. I put 10 gauge wire on it with 40amp inline fuse. I think I just need a bigger alt. Its been nothing but trouble

 

[jfrabat]

I have to do the same thing. I put a tarus efan in my jeep about a week ago and it is pulling too much from my alt, im blowing fuses and volts is only 11.5. I put 10 gauge wire on it with 40amp inline fuse. I think I just need a bigger alt. Its been nothing but trouble

That's odd; I ran my taurus fan (along with my sound system, which includes and amp and SW, all my lights, which includes 2 pairs of 100W Daylighters, both my radios - CB and 2m, and my GPS) with the stock alternator for a couple of years without electrical issues. I swapped the the alternator because I wanted insurance that I would not run out of juice, especially since I was installing my 9K winch and was planning on starting to use it, but the stock alternator did handle the load.

How are you running the Taurus fan? Do you have it on high speed? If so, that's not necessary; low speed is more than enough to cool the Jeep. Also, it helps to have a controller with a soft start option, as that reduces the amp draw...

 

[Turbogus]

I'm no electircal expert but it seems I've read from others (here and elsewhere) before one invests in a high amperage alternator one should check out their batteries as our electrical components draw from them rather than the alternator itself. I'll see if I can find that write up.

Partial quote;
Winches will draw 500 to 700 Amps (Amperes) of DIRECT CURRENT when in 'Full Pull'.

There is no generator/alternator out there that would produce that much DC energy to power the winch directly.
It would take a separate V-8 engine and a DC generator the side of that V-8 to produce that 500 to 700 Amps directly
Not very practical to tow around an 800 pound engine and 2,000 pound generator everywhere you go!

Enter a second battery...

 

[69jeepcj]

Well, I do need help with this. should I start a sep thread to not hi- jack this one or do the two kinda go together? YES, I run the fan on high, but is on a switch and can run on high or low. This is how I have it wired, no thermo switch or relays, I bought a 3 way switch (on-off-on). The fan has 3 wires one red striped one yellow striped(cant remember which was the high) and a black wire, I grounded the black to the grill, ran the yellow striped to the on at the switch and the other spriped wire to the other on at the switch, ran a hot from the fuse box to the switch which is at the off position on the switch. no fuse on the hot wire from fuse box to switch but have a 40amp fuse on the fans high and low wires. So, I leave the switch on high and it turns on and off with the key, or I can manually switch it to low or off. I put a larger wire on the alt and a 40amp small fuse, it blew that fuse so I put a large 40amp fuse and it hasn't blown it. Last night I was coming home and the on-off-on switch started smoking real bad, I shut the jeep down and pulled over and think I found two wires touching, moved them and it started back up and went home. going to look at it today and see if I can figure anything out. Thanks for your help!!

 

[jfrabat]

I'm no electircal expert but it seems I've read from others (here and elsewhere) before one invests in a high amperage alternator one should check out their batteries as our electrical components draw from them rather than the alternator itself. I'll see if I can find that write up.

Partial quote;
Winches will draw 500 to 700 Amps (Amperes) of DIRECT CURRENT when in 'Full Pull'.

There is no generator/alternator out there that would produce that much DC energy to power the winch directly.
It would take a separate V-8 engine and a DC generator the side of that V-8 to produce that 500 to 700 Amps directly
Not very practical to tow around an 800 pound engine and 2,000 pound generator everywhere you go!

Enter a second battery...

That is correct; the amp will not run the winch. But the more it provides power to the battery, the slower you drain it. I did replace my battery with an Optima at the same time, though. Also, the higher the Amp in the Jeep, the faster you can recharge the battery regardless of the other electrical components that are running... At least that is my understanding (not an electrical engineer either)

Well, I do need help with this. should I start a sep thread to not hi- jack this one or do the two kinda go together? YES, I run the fan on high, but is on a switch and can run on high or low. This is how I have it wired, no thermo switch or relays, I bought a 3 way switch (on-off-on). The fan has 3 wires one red striped one yellow striped(cant remember which was the high) and a black wire, I grounded the black to the grill, ran the yellow striped to the on at the switch and the other spriped wire to the other on at the switch, ran a hot from the fuse box to the switch which is at the off position on the switch. no fuse on the hot wire from fuse box to switch but have a 40amp fuse on the fans high and low wires. So, I leave the switch on high and it turns on and off with the key, or I can manually switch it to low or off. I put a larger wire on the alt and a 40amp small fuse, it blew that fuse so I put a large 40amp fuse and it hasn't blown it. Last night I was coming home and the on-off-on switch started smoking real bad, I shut the jeep down and pulled over and think I found two wires touching, moved them and it started back up and went home. going to look at it today and see if I can figure anything out. Thanks for your help!!

OK, wait a second; you are running the fan DIRECTLY from the switch? No relays? No wonder it was smoking... You need to use the switch to run a relay; switches are not meant to handle that kind of load. You will have an electrical wire under the dash if you keep your current setup!

Also, once you install the relays, keep in mind that the low speed may be fine with a 30A relay, but you will need a larger one (more than 40A; the fan can pull upwards of 70A when it starts running, reducing as the fan picks up speed, and settling to around 35A). Also, small fuses will not work; you will need Maxi Fuses to run 40A loads. Wiring is also a factor; you need to run larger gauge wires to handle all that current so you don't melt your cables out in the middle of nowhere when wheeling. TRUST ME ON THIS ONE; THAT IS NOT FUN!!! Don't ask how I know!

 

[Turbogus]

When I wired up my fans (Merc Mystique) I wired each fan independantly referring to this (and other) diagrams;


Testing with an override incorporated in this setup and they're working fine with 40 amp relays. Over the past year I've been review various diagrams and this one made the most sense to me. (A lift of the lynch lid to Mike Coiz for the diagram)

 

[69jeepcj]

Yes it is run directly off of the switch. im not very good with electrical stuff. So, do I absolutely need a relay?? I talked to my brother today, and he said that I could use a circuit breaker instead of a relay, correct or no?? because he said he has one I can have. I did switch to the maxi fuse after the smaller one blew, and went up to a 10 gauge wire. I pulled the jeep into the garage earlier and going to take a look at it in just a bit. Thanks again

 

[jfrabat]

Well, you don't ABSOLUTELY need a relay... You just need one if you don't like your dash to catch on fire.

Circuit breakers would replace the fuses, not the relays.

I am by no means an expert, but as far as I understand, here is how it works:

1. You DO NOT want high amps in the dash, as you run the risk of an electrical fire INSIDE the Jeep (fire is never good, but INSIDE is even worse!).
2. Since you only handle small loads inside the Jeep (especially in the dash), you run your switches with small amps and small fuses (say 2A).
3. Your switches will signal the relay, which in turn makes the high load connection (in this case, 40A). So basically, your switch is a small load that activates a high load switch (the relay) further down the line.

Another thing I just read is your ground; make sure the ground is good. If your ground is not working at 100%, you can create more electrical load unnecessarily (or at least, I have been told so).

I suggest you take a look at the circuit posted above; it seems to have been thought out pretty well.

 

[jfrabat]

When I wired up my fans (Merc Mystique) I wired each fan independantly referring to this (and other) diagrams;
View attachment 17261

Testing with an override incorporated in this setup and they're working fine with 40 amp relays. Over the past year I've been review various diagrams and this one made the most sense to me. (A lift of the lynch lid to Mike Coiz for the diagram)

That's pretty much how mine is wired up; of course, now my DC Controller failed (for some reason it is not turning on), so I now have to replace it (already have the Flex-a-Lite one sitting in my garage for that purpose). Truly functional to wire it up like that.

 

[Turbogus]

The really nice thing about this 'roll your own' is if something goes haywire one will know where to look more easily and the componentry is affordable and normally locally acessible. I've seen other make this remark on the home built controls.

...and from the good book of JeepHammer;

RELAYS are used when you want to keep the wiring sizes reasonable.
There is no sense in running a highly loaded, 'HOT' 10 Ga. wire through the firewall,
Through a switch that isn't rated for anywhere near the amperage a 10 Ga. wire will conduct,
Then back out the firewall 'Hot' to what ever load might be on the other end.

When the switch is 'ON' the wire is hot both directions, and we all know what happens to wires stuck through holes in the fire wall...
Even if you use a 'Grommet' in the fire wall hole,
Eventually vibration and the weight of the wire will cut through the Grommet and then the wire insulation, and you have a MASSIVE short circuit!
(Excellent time to have a properly sized fuse or fusible link in the correct place!)

A RELAY lets you leave the Large Wires out in the engine bay,
Keep the short so they don't build a lot of resistance in the circuit,
And they keep you MUCH safer by NOT having them running in and out of the firewall,
Plus, a Relay can handle many times what a 'Switch' on the dash can, do it safely, and do it for YEARS without issues.






These quotes are from another forum but I'd rather not post link as I've been called on this before

 

[jerzeydevll]

thanks ...

 

[69jeepcj]

Jerzeydevll, I didn't mean to hijack your thread and hope your question got answered. I will try to answer it for you if not. As I under stand it you would need to find out how much amps your fans will draw, I know the ford Taurus efan draw around 100amps at start up then drops down to around 35ish once it gets going. Find out what amp alt you have now. I had a 95amp alt and am running the Taurus fan. With headlights, radio, heater, wipers all being powered by the alt, I think im right on the raged edge of needing a bigger alt. The yj may come stock with a larger amp alt then I have, so you need to check. If you exceed the amp output of the alt or real close to it I would get a bigger one. They have 135ish amp alts for stock replacement at your local auto store. hope that helped and sorry again

 

[69jeepcj]

Up Date on mine. After looking at the jeep yesterday I found it wasn't the fan switch smoking at all, and in fact had nothing really to do with the fan. I found a exposed wire where I had put in a inline fuse, I had crimped it back too far and some wire was exposed and had rested on top of my metal steering column and melted the fuse holder which was near the fan switch, so I jump to conclusions that it was fan related since I have been having problems with the fan. I do see though that I will need to get a relay and I will probably wire the high and low side of the fan with two separate switches and run a relay for each switch.. Thanks for your guys help

 

[Turbogus]

Actually 69jeepcj, you can use a double pole double throw switch (DPDT), to cut the clutter on the limited space we have on our dash panels. I got this one from Rat Shack and as I'm running the Merc Mystique/Ford Contour double fan setup the low speed is controlled by the resistor on the fan shroud itself. Therefore I wired each fan with the little controllers I got from NAPA and as far as the switch goes, one hot pole goes to this controller for thermostat control and the other pole of the switch is an Override On circuit. In this setup then while dual contollers and dual relays are being used only one DPDT switch is needed.
I hope this helps, initially I was mysitfied myslef by this fan upgrade.

 

[jfrabat]

I think he has the single fan dual speed one... For that one, just make sure both speeds cannot come on at the same time, and you should be fine. In my case, I use a 3 position switch, where the middle is OFF, the bottom is AUTO (it activates the control box; at this time, the box is not working, so down does not do much, but once I replace the DCC with the Flex-a-lite controller, this will work once again - The control box is wired to the high speed side of the fan, but the box can control the speed), and the top runs through a relay (dont remember if it was 35A or 40A) to the low speed side of the fan.

 

[69jeepcj]

Thanks a lot guys, I went out last night and got a 40A relay to wire into the low side of the fan, (hopefully today). They didn't have any relays over 40A at that store, so I am going to keep looking for a 70A relay for the high side. I am going to look at the diagrams above to try and wire the 40A relay and just use the low side for now until I can get ahold of a 70A. Oh, and yeah I have the two speed, three wire ford Taurus single fan. Could I use the double throw pole switch posted above to run the low and high side of the fan instead of dual fans?? I have the three way switch now on-off-on, for high off low or should I just use two switches? thanks!