Oh, well i’ve got a couple of those kicking around. it’s not like the S1 and S2 where it’s completely enclosed.
Thanx for sharing
Adds weight to the round?? Way back when, crankshafts were drilled and the hole filled with Mercury, then capped to achieve balance.
In gold rush days, Miners used Mercury and mined it. creating huge environmental disaesters. It got into the water along the Delta and into the bay. Fishing is good, but risky. Mercury laden!!
Carl
1 Like
First off, are we talking about the battery box or the Aux radiator fan?
Short answers
- Battery box - it varies depending on the temperature inside the battery box.
- Aux electrical radiator fan- only when the radiator coolant is out of spec or a system fault (regardless if the car is on or off).
Aux radiator cooling fan
If you’re referring to the Aux electrical radiator fan?, the fan is controlled by a temp sender in (or on) the radiator signalling a relay to turn the fan off or on. As long as the temperature of the coolant in the radiator is with in the (temp) spec the fan is off. otherwise the fan will stay on until the coolant temp drops to within spec. This fan will continue to run with the key out of the ignition until the coolant temp drops to spec. the fan will stay on until the battery is dead if either the closing circuit diode or the temp sender or the relay is damaged / faulty.
Battery Box
On my '74 XJ6 SWB Series II, (the only functioning battery box).
The fan goes on and off depending on the ambient temperature inside the battery box. The mechanism consists of a bi metal spring (or switch) that expands and closes the fan circuit. Then when the temperature inside the battery box drops the spring contracts opening the circuit to the battery box fan.
I Does this answer your question?
Not really. I understand how it works. I was asking about how often it works. And yeah, I was asking about the fan on the battery, since that’s what I thought this thread was about.
Oooooo! Shipwright’s hit *** hard***…
Well mine did not work at all by the time I got the car. The fan was inoperative, if I remember correctly there was a plastic fan blade that was warped, and the bimetalic switch was permanently open. The battery box did look nice tho.
**
It’s unanswerable, Kirbert - it will run, if at all, when the box temp passes the trigger temp. Which will likely vary with ambient/engine compartment temps and battery load…?
Heat the sensor until the fan starts - checking the temp with an infrared thermometer. It won’t answer your question, but will tell if your set-up works. I don’t think anyone regularly times battery fan operation…?
Frank
xj6 85 Sov Europe (UK/NZ)
**
2 Likes
Kitbert, my answer is:
It does not work 
1 Like
I have two little telltale LED’s in my series 1 DDS, one for the aux radiator fan and one for the battery box fan. When I repainted my battery box I checked the fan and the bi-metal switch within the box worked using a hot air gun. I can tell you that even in the hottest UK summer day and in heavy traffic when the aux rad fan is very busy I have NEVER seen it on in the last 7 years!
……… and yes the air is drawn from the scuttle vent, through the battery box and blow out into the engine compartment. There is a flap valve within the box to prevent engine compartment air going back the other way.
Best regards, Mike
1973 Series 1 DDS
1 Like
I tested the bimetal switch with a heat gun: as dead as a parrot… But modern replacements for these are a dime a dozen.
Here is an update.
A little video tells the story better than written words. Me happy. One quirky thing resurrected!
2 Likes
And to complete the thread, here is the test of the thermoswitch. It works!
Does that fan run the right direction? I can’t tell from the video.
That is simply a question of the polarity. Did not matter for the test.
1 Like
…dead as a parrot.
2 Likes
Well, it resuscitated!
In commemoration of Terry Jones, who died just a few weeks ago …
2 Likes