First off the truth... I am not or ever claimed to be a wiring wiz kid !!!!
Problem, I am installing 98 Winstar e-fans in my F 250 ... the secondary fan will start with the A/C clutch and have a manual over ride switch ... simple huh !!!

The primary fan will run thru a Hayden 3653 adjustable t-stat ... this is where the issue starts in Hayden's wiring diagram first on the list >>> Hayden - Instruction Sheets it shows the t-stat connected to the ign. (12v+) and to another (12v+) switch wire going to the fan (mine will go to a relay to give power to the fan) ... am I over thinking this ... or is there no ground needed for the t-stat to work ??? .
My over ride switch is going on the secondary fan... or should I put one on the primary fan also ??? Dave

 

if im looking at the right diagram. the "mount under dash switch" is the override to turn the fan on if the thermostat doesnt kick in , but if you have the second fan wired on a switch along with being wired for the ac then you shouldn't need it for the one with the controller. unless of course you want to have a switch for both.

that controller should have 2 wires. one has a 12v keyed source the other is power out to the fan/relay. there is no need for a ground as its not an electric t-stat. there is a piece inside that once it gets warm enough it touches the contacts together to complete the 12v line to the fan/relay. think of it just like a in line toggle switch.

 

Look... the clouds are clearing away it's going to be a sunny clear day LOL !!!
Well that cleared up my thinking ... or overthinking to be exact THANK YOU !!! The printed sheet they send with the t-stat has been copied till it is blurry and doesn't say that the under dash switch is an option... in that case I just might do both, just to be safe here in the land of 100*+ summers
Thank you for your insite on my confusion it's easy for us "old people" ...now, I can finish my control panel for the fans ... Have a GREAT Sunday... Dave
I tried to give you some REPS... but if won't let me I sez I gotta spread it around

 

Glad it cleared things up for ya. The reason they don't show that switch as "optional" is when only running a single fan and if the T-stat fails there has to be a way to turn on the fan. But since you have duals and have a switch on the second one anyways that takes its place. I knowi would have both wired to switches in the cab just incase

 

[QUOTE=Midnite1987;11936118
that controller should have 2 wires. one has a 12v keyed source the other is power out to the fan/relay. there is no need for a ground as its not an electric t-stat. there is a piece inside that once it gets warm enough it touches the contacts together to complete the 12v line to the fan/relay. think of it just like a in line toggle switch.[/QUOTE]

Midnite, Howdy there, everything on my E-fans is working fine EXCEPT the Hayden t-stat ...I think, I seem to have it adjusted so the temp doesn't go above where it did with the old fan in place... but it won't shut off. it won't over cool any more than it did before. It seems that the water t-stat is setting the lower end temp range. when the A/C is on the upper range of the gauge stays with in the "N" in normal on the gauge. Just to check it, I set the Hayden controller higher and the temp does go up ... but still never shuts off. After a long time with the truck not running... overnight cold, when I start the truck the fan runs from the start, but if I "tap it" slightly with something it shuts off and restarts when it reaches the set temp. I think it is defective because I think it is designed to restart 15 to 20* below the set high temp. I will recheck it in the AM ...our temps have been running in the low 100*'s with AM lows around 65* to 70* ... by next weekend they were talking 112* + or so,... WHEW, now that's hot, I don't care who you are !!! LOL Just lookin for another opinion on this issue ... THANKS ,... Dave

 

Mine did the same thing. I turned the fan so it turned on a little warmer. I found on the highways truck woul run between. The R and M without the fan on so I set the fan to come on just above that. I thinknit had something like a 15-20* difference between cut in and cut out. If you set it to turn on right at the normal operating temp it will not turn off. I set mine to cut In just above the M and it would cool down to the normal running temp and shut off. As far as it still running when starting after shut down all night seems like your T-stat might be sticking. I got the electric version of the one you got.

 

Hey thanks, I will give it a shot t-morrow and check it out I'm thinkin I need a REAL TEMP GAUGE not a Ford one too ... I have been told the factory gauges kinda mmm off a bit !!! Have a good rest of the weekend... and Happy Fathers day ... if it apply's ... Dave

 

Doesn't apply to me as of yet lol and happy fathers day to you (if it applies lol)

 

OH, it does, even grandpas day too Have a great Sunday any ways LOL !!!