Back story: Engine replaced, tranny replaced, later year plastic rad, new tranny aux cooler, 75 carbd 350 engine in an 83

Had clutch fan setup for like 2 days after dropping it all in.
Swapped an '88 single electric fan in.
Wired it directly to a switch for like 3 days.
Yesterday, wired up a realy. Positive side of relay switch connected to the electric choke power wire. It has 12v when key is ON. Connected the ground to the temp switch in pass head. Soo, the fan does not turn on until the car has been sitting at 260*+ for a couple mins. Now instead of ground going to temp switch, I wired it back to the manual switch.

Here's what I have:
Gauge Temperature sender: TU66
Fan switch: SW500 - Closes at 220*-239*
160* Thermostat - I THINK

Now the thing is, the old block is 1/2x14 thread. The switches are 3/8x18. I got adapters from home depot to change the thread. The temp gauge sender has a brass adapter. The fan switch has a chrome adapter, they didn't have brass at the time.

Gauge reads on the mark between 100 and 220 with fan kicked on all the time. When I had it on the temp switch, it goes upto 260+, then kicks the fan on, which in turn brought the temps down and turned the fan off on the mark between 220 and 260.

What should I do? Which switch do I use?

 

I would check that teamp with a infra red thero gun..maybe the gauge is screwed up !!!!

 

Where would I read temp at exactly? We have one of those guns at work.

 

I would check it at the thermostad neck !!

 

Roger that, will see tomo.

 

Gauge reading between the white mark in the middle of 100/220 and 220.
Temperature at:
Fins on pass side right next to rad cap: 169*
Fins on drivers side right next to outlet tube: 180*
Thermostat neck: 190*
Car off. Fan off.

These are temps after immediate shutdown from driving 20-30mins. Flipped the fan on for like 10 mins while slow driving to keep temp under 220.
The temps rose with the car off after standing a couple mins.

 

So , what is the problem.....seems normal to me !!!!

 

Hah, problem is, I have to manually flip the fan on. The SW500 switch turns the fan on when the gauge reads 260+. If I were to go with a cooler switch, which should I get?

 

I would get a 220 on/ 190 off

 

That's what the Autozone SW500 is^^.
'Nother question, what is the difference between a single terminal switch and a dual terminal switch besides connecters?


and this

 

I just bought an SW500 from autozone. Are you saying it causes the fan to turn on too late?

 

In my case, it did. But keep in mind, my setup is wacky. 1975 350, I had to use an adapter to make the SW500 fit my head. It could be something with my setup. Wait till one of the pros chimes in on the SW500 itself.

 

Any chance your adapter is not conducting electrically well enough to enable the switch to ground through the block as well as it should? If so, switch adapters

 

I have no idea.
The switch could be a faulty new one.
The "chrome" adapter could be doing something funky.
Theoretically, if the fans flipping at 260+ when then switch is for 230, I can get a switch for 180 which should turn it on at 210. Unless the resistances change exponentially?
I don't know.
If I change the adapter to a brass one and that doesn't work with the current switch, I don't want to do it again. It's getting way to cold now for coolant to be spilling all over my hands. Plus it's a waste of coolant.
You'd think popping in a switch for stock temps would just work.
Bahhhhhh
Also, still looking for an answer on those two blade switches. All 1/2" switches are two blade. That way I wouldn't need an adapter.

The adapters I used are Home Depot Watts A-828. That's the brass one for the gauge sensor. The 'chrome' one is A-828F I think.

 

Sounds like your gauge may be off. However, it is possible that something is a little messed up. I bought a Jet fan switch from Jet performance Products. 195* on, 185* off. My gauge is definitely off because when the fan turns on...it's reading over 220* on the gauge.

 

I thought about this again, and...did u ever compare the gauge temp with the laser thermo temp ?????

I mean,,,yes..the gauge could be WAY off !!!

I mean. let run untill the fan kicks on ( ~ 260 ) then use the thermo gun and shoot at the thermostad neck and see what u got , if its more like 220-225 then u know u are fine and the gauge is off..if u are really at 260 + then u know the switch is wrong !!!???

 

Actually, no I haven't. That seems like a good idea. I'll keep reading it as the temp rises. Thanks for the suggestion! I'll try it when I have a 3rd hand around.

 

let us know how it worked out !!!!!!

 

Haven't got to it yet. Don't have a second person to read the gauge. In time...


Have you verifed your temps with an outside monitor, ex. a temp gun?