Rad and Fans Query

[Adtheman]

Hi There. Any of you guys running a Dewitts rad with dual Spal electric fans. If so where is the temp relay sender. Ive got mine in the rad but it doesn't seem to get quite hot enough in that part of the rad where the sender is. Changed out from a 195 to a 185 but not seeming to cut in. Its almost as if the rad is far too efficient for its own good. Manual override all working fine so i know the wiring is good. The temp gauge in the car is running around 210/220 which i know are not that accurate but it is getting hot. Its hotter on the top hose and thermostat housing than the area of the rad where the switch is. Other option is to re route the sender unit to the cylinder head, bit annoying as this should work where it is.

 

[Forrest Gump]

Where in the rad is your sender positioned?
I've got my sender in the top left corner of the rad. That is the hottest point of the rad.

 

[stealthyflatfish]

Not DeWitt's but Champion, makes no difference. Got an electric fixed temp thermostat on mine, cut into the top hose with an inline coolent housing, think mine was 42mm ( big block ) diameter, but check. Available in UK from most performance stores.
Works spot on accurate and tidy.
Tried the bulb refrigerator type switch which i found very inaccurate and untidy. Top left picture is fitting, thermostat hangs underneath.

 

[Adtheman]

Where in the rad is your sender positioned?
I've got my sender in the top left corner of the rad. That is the hottest point of the rad.

Yep top left corner it can’t be faulty as I’ve tried a 195 and a 185

 

[Forrest Gump]

The senders might be good but there could be a problem at the other end? There's some kind of module holding the relays etc I assume.

 

[Forrest Gump]

Is that a bulldog clip on your carb?!!!

 

[Adtheman]

The senders might be good but there could be a problem at the other end? There's some kind of module holding the relays etc I assume.

yes bottom left of pic attached to bulkhead

 

[Adtheman]

Is that a bulldog clip on your carb?!!!

Yes, Don't worry i'll take it off before i put the air cleaner on

 

[Forrest Gump]

yes bottom left of pic attached to bulkhead

If you ground the sensor wire does that bring in the fan?

 

[sublimemike]

I run an auxiliary electric fan switch below the dash. Saves fretting if you see the temp dial rising and worrying if the fan(s) have cut in.

 

[Adtheman]

I too have the switch under dash. Managed to sort the problem now by re earthing.