OK, so I have been noticing something odd, it didnt click till today exactly what was happening.

So it had been seeming like the Primary and Secondary fans were just randomly kicking on one or the other, but never both at the same time.

So, it just clicked to me tonite that the Primary runs when the car is first started. After a short time the primary kicks off and the Secondary Kicks on.

I had just put in a 180 or 185 Fan switch (cant remember) in the pass. side head.

So what it appears is that when the car reaches 180 or 185 whichever it is. The secondary fan kicks on, and then the primary kicks off.

Now I have done a 350 swap into a 305 tpi car. I put in a prom from a 87 350 TPI and mine is a 88. I dunno if the tune was stock or upgraded to keep the primary fan on or not...

so...... what is going on here? I am not really good with electrical, and im baffled as to why when the one fan kicks on, the other turns off.

thoughts?

 

anyone?

 

Comon, somone has to be able to chime in and point me in the right direction!

My primary fan is kicking off when the secondary kicks on.

thoughts?
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I have tried unplugging the secondary fan and the primary kicks back on, I just dont know what would be causing the primary to turn off when the secondary kicked on?

Bad Relay?

I dont know why the primary would be running all of the time either, but I am assuming it has something to do with the prom that I got from the 87. Assuming it must be tuned to run the fan all of the time, but that could be an unfair assumption.

Not really good with electrical troubleshooting, so need some guidance guys...

 

Maybe I am confused.

It is the drivers side fan that runs when the car is started. Once it reaches 180/185 the Passenger Side Fan Kicks on and the Drivers Side Turns off.

Which of the 2 is considered primary/secondary?

I cant get the car to go much past the 1st notch on the temp guage unless I unplug fans, so I have been unable to get it hotter than that to see if the drivers side fan kicks back on when it gets hot.

I cant really test the A/C because my AC box has a hole in it from melting last summer.... Long story. But I have a replacement box to put in sometime this summer.

Sending out an SoS here guys, need some feedback.

 

I have done some searching, didnt really find anything that was helpful.

anyone?

 

how is youre battery or alt?
maby youre alt is buggerd and when the second fan switches on it is drawing so mutch power that it is overloading the alt and there for it has insufficient amount of power to keep the primary going.
What dose youre Volt Meter read when idleing with no fans?
(mine sits around 13-14V with fans off).

Duno just a thought.

 

Alt is starting to whine a little bit. Needs to get replaced.

I havent tested the battery while running.

 

Im not 100% but I recon that could be youre problem then.
Dose the Alts belt squeal when the second fan comes on? or do you feel extra load on the engine at idle.
when both my fans come on i get a 100 to 150RPM drop from the extra load on the Alt.
(but im running 2700CFM dual thermo fans out of a mid 90's V8 not stock ones).

EDIT: i just thought of a way to test it, Ok at idle 1 fan running put a volt meter on the battery then wait for the second fan to engage and see what the volt meter reads when it dose.

 

Hrmm, I will have to try that.

I only notice the altenator whining at idle.

It doesnt really do anything different from what I can tell when the primary kicks off and the secondary kicks on. I will have to pay more attention though when I try it again.

 

allright well uvve pretty much got it all wrong lol.. the primary, left fan when looking at it from the drivers seat is supposed to turn on once the car gets hot, if u happen to be starting the car when its already hot it will turn on right away.. the other fan is your secondary and a/c fan.. when u turn on ur air conditioning it turns on and depending on your car your other fan may turn off when the 2nd turns on however most dont. but if they randomly turn on and off especialy when cold and a/c not on u got a problem, fan relay? coolant temp sensor? a/c switch? thats what we mechanics like to call a ghost.. nd depending on whats wrong it can be a pain in the ***** to find

 

Thanks for responding.

I know I have a problem with the AC pressure switch because the box has a hole in it, so it wont build pressure and turn on with the AC.

I guess it wouldnt be so concerning that the primary isnt running and the secondary is if the primary wasnt running on startup for whatever reason.

Mainly because the primary isnt supposed to kick on stock till like 222? and with the secondary fan switch at 185 it would run before the primary.

I dunno, I am gonna do some playing around, but I guess I need to first figure out why the primary is running at startup.

If anyone has any other info, please chime in.

 

I have a feeling that part of my problem may be because of this.

What is this connector specifically?

And... what does the "F" connector do. That light green? wire appears to be completely gone from the harness on both sides.