Got an '88 TPI harness but its not set up for dual fans.

Call me strange, but I want to run my dual fan setup similar to the factory setup...one fan on with ECM control for primary cooling, the other one as a "backup" fan.

I don't have AC.

I've got to add in all the wiring for the second fan (easy, have the wiring manual) but I'm curious if there is a way to get the second fan running short of just using the 232* (according to my wiring manual) second coolant switch that was stock for a dual fan setup this vintage. If there is not, is there any 220* switch that I can use instead of the 232* for the secondary fan?

I was hoping there was some way to use the ECM for the second fan as well, so I could change the engagement temperature, of it like the primary fan and although it seems unlikely, I figured I'd ask. I can't think of any other ECM pins that are temp "outputs" that I can use, but maybe there is another way to approach that, which I don't see.

What I don't want is to have both fans on at the same time, because I know I won't need it. I don't run hot as is, but if something were to happen, or I needed the additonal cooling, its nice to know its there. I also don't want any "manual control" (IE toggle switch) over the fans. Since I don't have cooling problems as is, as long as I get the fans cooling the way I want (I want 195 as the minimum temp, but like a 210 cut in for the primary fan, 220 or so for secondary fan) I would much rather not have to mess with them while I'm driving.

Any ideas or thoughts would be great.

Thanks!

Dorian

 

maybe if you got a 180 thermostat, you could get a fan switch that turns on the passengers fan at around 200, and u can leave the primary fan alone.

that sounds like the cheaper and best way to do what you need.

http://www.thunderracing.com/index.c...ategoryid=1120

 

The only thing is, I've got to add the second fan wiring anyway, if it can be modded to do what I want to do, I might as well do it now. 195 is the temp my vehicle will/does run.

Just trying to figure out if there *are* any other options out there, besides just wiring it up "stock". I like keeping things stock (wiring diagrams are always right then) but things like changing the fan cut in/out temp I have no problem with.

 

i dont think you can do anything with the wiring, remeber you said u dont want anything like switches and stuff.

i would just put in a 180 thermo and get that fan switch and your normal operating temp should be from 190 to 200.

so just use the stock wiring diring for the dual fans and plug in a fan switch and your done.

 

Well, normal temp with the 195 stat is 195, with a 2 core radiator, so thats just not an issue.

This isn't really a concern that it will overheat, more that its just me wanting it wired up to change the on/off secondary fan temp. I *really* doubt that I'll ever see even 210, but this is a truck, and should I have to tow or something unexpected with it, I'd like to know the second fan will be there as backup.

As I've seen repeated again and again, the Camaro's were "programmed" to run hot as is, and I do not like seeing an almost 40 degree temp variation in my engine when its running, especially since my cooling system as is, is more than up to the task of easily keeping it at 195. 40+ square feet of frontal area helps in cooling, but thats all it helps lol.

 

ok then it sound like you just need the fan switch then. however if you get the 200 fanswitch and stay with the 195 then the fan might be on alot!, thats why you should lower the thermostat so the system can have some lee way, like the stock etup does.

my car runs 220 and the primary doesnt come on untill like 227 - 230, and that temp only occures when sitting in traffic for awhile. so neither of my fans are hardly on. and the secondardy doesnt even come on until 237, and that never happens for me at all.

 

Ahh...gotcha now! : )

I guess once I get the new motor in (another 350) I can try running it with no fans, and see if it equalizes somewhere above 195 all by itself...if it will hold down low like 210 or something, I may not have to worry at all. Like I said, with this 2 core (and its a corroded old one that came with the front end I bought) I can keep it at 195 no matter what external factors act on it. No auto transmission to cool though, and I have a feeling thats a large part of it. I know this radiator will fail sometime soon (only running 13PSI cap, figure that will help life of the thing a bit) and when it does, I'll be stepping up to a 3 or 4 core (about the same price) and an uncorroded radiator, I can only hope that 210 or so with no fans is possible...I still want to try that with this motor, it doesn't appear that I ever really need the fan lol.

Just trying to get my options in order before the whole engine/carb to TPI swap takes place.

I appreciate the comments!

 

sounds like your all set then.

 

primary fan on the dual fan setup is programmed to come on at 222 F. at least in 1989.

the secondary fan is ~240

 

Yeah the '88 secondary fan switch is supposed to be 238. Just going to have to wait and see if it will keep cool by itself with no fans, before I go messing with switches, if its even possible : )

Dorian

 

maybe when it's 0 degrees outside

 

We'll see, others have done testing and not had much problems, and apparently the size of the radiator in the trucks must be a large factor in cooling compared to a Camaro. (about 2" taller and wider, 1/4" thicker) If I had to, I *could* go with the diesel radiator which would be 8" wider than the Camaro one.

The way I look at it though is that water is heavy, and I really only need to carry around as much as is necessary. The diesel one would be WAY overkill.

Dorian