thermostat?

[dan58]

My radiator led a slow, painful death, so I ordered a new one from radiator barn.com I spent a few extra bux and got the 3 row. This thing sees 95% of all time going SLOW in 4Lo. What temp thermostat would be best? 195?

[jeepsr4ever]

Yes I think your right on the money!

[dan58]

Yes I think your right on the money!

Sweet. I got a taurus fan, so this puppy should be good to do.

This is the simplist two speed writeup yet (I have no desire to have a thermosta controlling it).


The Taurus fan will have 3 wires... 1 ground, 1 high speed power, 1 low speed power. I just went to NAPA and bought 2 30A relays, wire the high speed thru 1, the low speed thru 1, ground it to the battery, and then power the relays off of a 3 way toggle switch. I had mine so up was low, middle was off, and down was high.

[tufcj]

I run a Robertshaw high flow 180 degree stat in my Jeep with a FloKooler pump and aluminum radiator.

If your cooling system is good enough to cool below the rating of the stat, it will close to keep the temp up. I like mine to stay cool when rock crawling.

Bob
tufcj

[1980_Cj7]

The hi speed on the Taurus fan really draws a lot of amps. Most guys I know, including me, are using a 75 amp relay for the hi side. Here's what happened to a 40amp fuse when I tried to get away with that. I replaced it with a 60 amp cartridge type.

https://home.comcast.net/~rwsr50/ComcastOnlineStorage/Melted_Down_Fuse_001.jpg

[Goose]

:shock: :shock: Wow.. thats a lot of AMPs.. (or did that crisp over time?)

[dan58]

80CJ, do you have a wiring diagram for your setup? I'm planning at 75amp relay for the high side and a 40amp for the low side.

[1980_Cj7]

:shock: :shock: Wow.. thats a lot of AMPs.. (or did that crisp over time?)

No, it was brand new, installed at the same time as the new 401. Upon the initial startup, while we were breaking in the cam, I saw smoke, then flames, and....

[1980_Cj7]

80CJ, do you have a wiring diagram for your setup? I'm planning at 75amp relay for the high side and a 40amp for the low side.

Here's the way I did it, excuse my crude wiring diagram. The fan is thermostatically controlled, and will run whether the engine is running or not. The switch is an ON-NONE-ON toggle so you can manually switch from low to hi, but there is no way it can be accidentally turned off. I ran a separate hot wire to each relay. Initially I had only one that jumpered between the two relays, but when the fuse in the picture above blew, it made me think...with only one hot wire and fuse, if you lose it, you lose the fan all together. With two independent feeds, if you lose one, you still have the other.

https://home.comcast.net/~rwsr50/ComcastOnlineStorage/TaurusFan.jpg

[ironman_gq]

I did the same thing with the wiring. I got a 75 amp bosch relay from watekwire.com for $26. The parts store wanted $75 for the same relay and it would take 2 weeks to get it. I used an adjustable thermostatic controller for mine and used it to switch the relay.

[mrtazwrench]

I did the same thing with the wiring. I got a 75 amp bosch relay from watekwire.com for $26. The parts store wanted $75 for the same relay and it would take 2 weeks to get it. I used an adjustable thermostatic controller for mine and used it to switch the relay.

I always pull all the relays I can from anything I scrap out most of the time I don't have to buy any. :mrgreen:

[dan58]

Thanks 80CJ. I think I'll use your diagram, minus the temp sensor. I need a fan running at all times.

[1980_Cj7]

That Flexolite temperature controller has a probe with it that they tell you to stick thru the fins of the radiator. Instead of doing that, I stuck it in the upper radiator hose, right where it goes on the radiator. The lead is very thin so I just smeared some silicone around it and clamped the hose with a hose clamp as usual. Haven't had any leaks. Fuzz did his probe this way too.

[dan58]

80CJ, can you post the link to the relay? I can't quite make out the letters. :oops:

[1980_Cj7]

80CJ, can you post the link to the relay? I can't quite make out the letters. :oops:

Sure. Bosch 75A, 12V #75252 Power Relay.

http://order.waytekwire.com/IMAGES/M37/catalog/219_061.pdf

[dan58]

Outstanding! Thank you, sir. =D>

[dan58]

FYI for anyone who considers the swap, the new Waytek p/n is 75552.

[ironman_gq]

Yep and its not a bosch relay anymore. I think they switched to an imported equivalent. same price and number just a different name.

[1980_Cj7]

I wondered what was going on when I tried to find the link for dan58. That explains it. The new product line is Tyco. They are the people who took over the old AMP (Aircraft Marine Products).

[dan58]

I just cannot get the wiring right. It's identical to the diagram above, but I've eliminated the Flexalite temp sensor. ANY ideas at all?

I've checked and rechecked all wiring connections. I have 12V from the positive TO the relays, but I have no juice FROM the relays. I did check the fans, and they do work.

[dan58]

I got the fan working, and I HIGHLY recommend the Taurus fan. That thing just flat out rocks for cooling. The low speed brings the temps right down.

[1980_Cj7]

Dan sent me a PM. The problem was the relay control wires. I have + going the 85 terminal on my diagram, and - going to the 86 terminal. Dan had to reverse these to get his to work.

I didn't think it would make any difference which was + and which was -, but apparently it does. I didn't really look at our Jeep when I drew up that diagram, so I'm not sure how ours is, but it works great. I even did a little research on relay wiring, and it seemed to say it doesn't matter. Dan did some research too, though, and said some relays have diodes built in, and with those it does matter.

Just a heads-up for anybody else who may be using my wiring diagram.

[mika01]

FYI I'm using a 160 degree thermostat, Flowkooler pump, electric fan, CJ heavy duty 3 core radiator and now during the winter months while driving I don't even need the fan, most of the time I keep it off.

[ironman_gq]

the bosch or tyco power relays have two diodes in them so it does matter which way you hook it up.