Radiator swap out questions

[Rich69]

A good MANUAL switch will run you $10...just sayin'...and a Gingko pill for the memory!!

Your getting closer to selling me on the Manual switch.

 

I'm guessing the reason I have read many have had problems findind the right switch is because the coolant coming out of the head is much hotter than where that bung is located halfway down the radiator. again I'm guessing for this to work right you would need a switch witch turns on off at a higher temp then the stock switch. ffpiercecracker1, I couldnt pull up the price from that link, I was looking t this switch:

 

http://www.summitracing.com/parts/der-16749/overview/

[ftpiercecracker1]

Try this link http://rodneydickman.com/catalog/product_info.php?cPath=21&products_id=233  You want the 210/200 switch $19. And you are 100% spot on with your hypothesis about the coolant being much hotter coming out of the head (where this switch will be) than where the stock switch is, at the bottom driver's side of the rad.   The trouble is how cold in the coolant coming out of the rad? I have determined there is about a 30* difference between the coolant coming out of the radiator and the coolant at the back of the head.

 

I know this because, i just finished testing a 199* switch in the lower bung and it did not turn the fan on until 230* according to the gauge in the dash, which gets its temp from the back of the head. Therefore, you need a switch that makes contact at roughly 180* and breaks contact at 170*. This means the temp at the back of the head would be 210* when the fan kicks on and 200* when the fan kicks off.

 

 

This is the only switch that fits the bill for the lower bung. https://www.carquest.com/webapp/wcs/stores/servlet/product_CARQUEST+Heater+%26+A%2FC+Switches+By+Wells__10151_-1_10651_457854?acesApp=1

 

 

I believe that between these two switches you would have a perfect cooling system, that would allow you to retain a/c and keep it simple.

[ftpiercecracker1]

and if you wanted to use an adjustable fan controller i have done a bit of digging on the Hayden system and it seems to be a pretty good little unit, very few bad reviews. cheaper too.

 

http://www.oreillyauto.com/site/c/detail/HDN0/3647.oap

[ParadiseMJ]

Your getting closer to selling me on the Manual switch.

 

I'm guessing the reason I have read many have had problems findind the right switch is because the coolant coming out of the head is much hotter than where that bung is located halfway down the radiator. again I'm guessing for this to work right you would need a switch witch turns on off at a higher temp then the stock switch. ffpiercecracker1, I couldnt pull up the price from that link, I was looking t this switch:

 

 

 

 

Yes...the coolant temp is higher at the head, and so the fan is designed to come on when the relative temp is ~20-25 cooler than what the GUAGE reads (remember, on the RENIX system they are 2 separate switches/sensors). If you ohm it out at the two the stock bung switch goes to 0.0 at 200.

 

 

This is the only switch that fits the bill for the lower bung. https://www.carquest.com/webapp/wcs/stores/servlet/product_CARQUEST+Heater+%26+A%2FC+Switches+By+Wells__10151_-1_10651_457854?acesApp=1

 

 

I believe that between these two switches you would have a perfect cooling system, that would allow you to retain a/c and keep it simple.

 

But if there IS no lower bung...the problem is finding a suitable switch...you know, since there isn't a bung...which started the whole discussion.

 

Even with a manual switch, or a regular switch, or an adjustable switch, or an alternately engineered switch...your fan will still work with the A/C - Defrost selection on the HVAC controls.

 

and if you wanted to use an adjustable fan controller i have done a bit of digging on the Hayden system and it seems to be a pretty good little unit, very few bad reviews. cheaper too.

 

http://www.oreillyauto.com/site/c/detail/HDN0/3647.oap

 

This sounds like a good option and you know, since it's adjustable, you can dial it in.  Other than a manual switch that is always available.

 

The REAL question is "Which Switch is Which"?? It's a Bi#ch!!    :???:

 

Another cerveza please.

[ftpiercecracker1]

 

This is the only switch that fits the bill for the lower bung. https://www.carquest.com/webapp/wcs/stores/servlet/product_CARQUEST+Heater+%26+A%2FC+Switches+By+Wells__10151_-1_10651_457854?acesApp=1

 

 

I believe that between these two switches you would have a perfect cooling system, that would allow you to retain a/c and keep it simple.

 

But if there IS no lower bung...the problem is finding a suitable switch...you know, since there isn't a bung...which started the whole discussion.

 

Even with a manual switch, or a regular switch, or an adjustable switch, or an alternately engineered switch...your fan will still work with the A/C - Defrost selection on the HVAC controls.

 

If there is no lower bung you need either a temperature probe, like the Hayden system OR find your self a Saab temperature switch housing from a

JY and splice it into your lower hose.  Threads for this are same as jeep 22 x 1.5 Metric

 

 

 

 

 

and if you wanted to use an adjustable fan controller i have done a bit of digging on the Hayden system and it seems to be a pretty good little unit, very few bad reviews. cheaper too.

 

http://www.oreillyauto.com/site/c/detail/HDN0/3647.oap

 

This sounds like a good option and you know, since it's adjustable, you can dial it in.  Other than a manual switch that is always available.

 

The REAL question is "Which Switch is Which"?? It's a Bi#ch!!    :???:

 

Another cerveza please.

 

Not following you. Which switch? Any old switch will be fine, so long as it can stand up to the current draw. ;)

[Rich69]

What year Saab is that out of? I really like that soloution. Cheap and easy and I can use the stock sensor......!

[ftpiercecracker1]

Stock sensor is too hot if you are doing a dual electric fan setup. As for the coupling i am not entirely sure of what year Saab, i would probably say mid 90s but to be sure set a week aside and read through this thread (41 pg), it talks alot about this and what switches can be used http://www.jeepforum.com/forum/f12/ford-taurus-wiring-solution-cheap-1325896/index11.html   Really good stuff in there, it just takes a bit to find it.

[comanchedude]

What year Saab is that out of? I really like that soloution. Cheap and easy and I can use the stock sensor......!

FYI dirt bound off-road sell a nice switch that installs like this one. and it have two different temp settings, dual sensor.

 

http://www.dirtboundoffroad.com/jeep-cherokee-xj/cooling/standard-fan-controller/

[Rich69]

I ran the MJ all winter wo a fan switch or any electric fan for most of the summer. Recently I was heading down the shore and knew I might get caught in traffic so i quickly wired a temp switch and set it on the top fo the dash. I picked up the newer T-stat houseing a while back with the 3/8" port. I took some temps with an infra read sensor after running the truck all warmed up. I found the tstat housing was about 205*-210*. I found the radiator close to the height of the missing bung at about 185* so the question is what is the best on / off temp for the new fan switch.

 

I was trying to find the spec on the thermostat as it should be above that. I would geuss the stock t-stat is 190 or 195 anyone know? Any suggestions on the on / off temp for the new switch? Jeggs and summit have a bunch of differnet switches which may work.