8 replies to this topic

[gdcarpenter]

Fairly new to me, 1990 Mini Mayfair 1000, Japanese Spec.

There is a temp sensor in a bung in a pipe spliced into the lower rad hose, I am sure this was for the existing electric fan, came to me with the fan hardwired to dash switch.

There is also the switch in the photo in the bottom right side of the rad, facing the grill. What would this have been for as currently no sign of wiring nearby. Can this be used to drain the rad?

For what it's worth I wonder if this Mini originally was an SPI version? The car had a John Cooper Garages Conversion very early on in it's life,
Has a CAT and a plugged bung in pipe behind the CAT for an "EXH" warning light/alarm in a switch panel.
Has remnants of a white nylon/plastic return line from engine compartment to fuel tank, with a one way valve at tank that only allows entry into tank, remnant of 'Charcoal Canister System'?

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[cal844]

That's for the fan, its actually mounted into the bottom of the radiator. It's better to have the fan on a manual switch as its easier to control. The switch pictured is supposed to control the fan, the owner may have caught the wiring in the alternator (happened to me, so I fitted the switch on the dash). To drain the radiator I usually just take the bottom radiator hose off at the water pump, the system will drain that way.

The seal and lock tab are available from Minispares.com.

If you look behind the auxiliary fan you should see a cylinder with pipes and a small vacuum hose going to a take off under the top radiator hose, this is your charcoal canister, the return line is a fume vent line.

Edited by cal844, 12 April 2020 - 10:19 PM.

[Aria Aradhea]

The bottom hose temp sensor is what would have come originally on your '90 Mayfair. Both of my JDM Mini is like that (they're late 89 and mid 90 cars). The temp sensor on the radiator is usually found on the radiators fitted to early 90s Cooper or post 92 (injection cars). 

 

It is a high possibility that your car has gotten a replacement radiator at some point and that replacement is for a post 93 car.

The bottom hose temp sensor should accept a Honda temp switch P/N: 37760-PB2-003. IIRC, similar Rover cars around the same era also uses that part (as they are now basically Hondas).

[MikeRotherham]

I use the temperature sensor on the bottom of the radiator to drain the radiator and pipework.

 

I find that if you cover the area around the bottom of the radiator with plastic or old carrier bags its possible to direct the old coolant away from the body and makes a lot less mess.

 

You'll need to get a replacement seal for when you replace the sensor. They are available from Minispares as someone said earlier.

[gdcarpenter]

Thank you all gentlemen. Nice to know I have options for controlling the auxiliary fan. Will run with hard wired switch for now, though automatic is tempting in case one isn't monitoring the temp gauge well,

[cal844]

Thank you all gentlemen. Nice to know I have options for controlling the auxiliary fan. Will run with hard wired switch for now, though automatic is tempting in case one isn't monitoring the temp gauge well,

Automatic sender is too much to go wrong, keep it simple. As a rule if you are in traffic or the guage goes over half I switch the aux fan on. I've also had to use the heater fan to pull heat from the coolant

[Aria Aradhea]

The twist-in sensor at the bottom of the radiator can be quite unreliable, but I found the Honda sensor to be excellent. Especially if you regularly use the AC, temperature can creep up without you realizing.

Should you use the sensor, I'd recommend using the one from the bottom hose instead of the one from the radiator.

[gdcarpenter]

Thanks again,
Alas a lack no AC, will see what the hot summer here in North Carolina, USA does. So far with limited runs she has kept her cool. Agree with the 'KISS' principle, "Keep It Simple Stupid", or as the saying goes, "If it ain't broke don't fix it".

[Aria Aradhea]

Thanks again,
Alas a lack no AC, will see what the hot summer here in North Carolina, USA does. So far with limited runs she has kept her cool. Agree with the 'KISS' principle, "Keep It Simple Stupid", or as the saying goes, "If it ain't broke don't fix it".

If you're running a 998 with no AC, chance are the engine is good in coping with the heat, unless you're stuck on a particularly bad traffic.

But, you still have the aux fan that you can switch on any time. So, all is good!