Running hot and cooling fan not coming in

[fastivaca]

Looking for some advice. The B6T is running hot and the cooling fan is not kicking on. Here's what I have checked:
- timing is set as per Mazda specs
- there is 12 volts at the correct terminals of the relay with the key in the run position
- fan does work, verified by hooking directly to battery
- fan does NOT turn on when I unplug the temperature sender (engine running and definitely up to temperature).

What should I be looking for next? Could the thermostat be stuck shut?

Thanks

[sketchman]

You said you checked the terminals of the relay. Did you check the terminals at the fan connection?

One of ours has corroded to the point that the fan would not come on at all. Cleaned it up, or lately just clip it and install a new set of plugs, and it woks again.

[fastivaca]

You said you checked the terminals of the relay. Did you check the terminals at the fan connection?

I haven't. Will do so a bit later. Going to run some errands while the car cools down.

Thanks

[fastivaca]

OK. Had power at the fan plug, cleaned the contacts and now I have a fan!!!

[bravekozak]

I re-terminated all of the non-sealed connectors. Fan plug, parking lights, alternator, etc.
It is very difficult to wire Dremel the interior of the brass female terminals.
Twenty-five years of oxidation is best replaced with identical open barrel terminals from Canadian Beaver.
With a little practice, it only takes about three minutes a connector, to pop out the old terminals, cut them off, strip 1/8" to expose some shiny copper, crimp on a new terminal and click it back in. Good for another twenty-five years.

[1garyz]

it also does not hurt to push in some dialectic grease into the female side of the plugs to help keeps moisture and hosing the engine compartment out of the connections. the terminal set there, Canadian Beaver, can i look up a website under that name and find a terminal set like that or do you have to order individual terminal types to make up the set you had there?

[fastivaca]

I'm pretty sure I have the cooling issue sorted out. I replaced the rad and switched the cheap e-bay slim fan for a brand name one sourced locally. More details in this post in my build thread...

Ian