Cooling Fans

These motors are indifferent to polarity, so the position of the connectors is irrelevant. But leave it to Lucas to confuse generations past, present and future by providing what appears to be a polarized plug. Numbered no less. Doesn't your wiring harness have two simple female Lucars?

Long answer to a simple question:
1) Your car originally came with series wound motors...there are two 1/4" connectors built into each fan chassis, and polarity doesn't count. These motors had a "square" cross section, and were painted hammertone silver.

2) Some vintage subtitutions used later Lucas motors which had permanent magnets. These are polarity sensitive, but again, there are two 1/4 inch terminals.

3) Aftermarket, anything's the norm. If you have a pair of Coolcats, then they will have 1/4 inch connectors on black and orange leads.

In the latter cases, polarity counts, but if you reverse, the fan will simply run backwards, no harm. One wire going to the fans is hot. The other wire goes to a relay contact: the other relay contact will be ground.

I have no idea what you mean by a "lug", or why your fans wouldn't have two connectors. A photo might help.

The relay should NOT be energized all the time. Even if you have A/C, the relay will only be on when the A/C is on.

Those are original 1.5 and 2 series Lucas square motors. Should have 4-blade oars for fans. If I recall, the original plugs had a knob on one to fit the slot shown on #2.If not, should be field wound (like heater motor and wiper motor) and shouldn't make any difference on running.
Dave

Mike,

The end cover of the square style fan motors has two square "receptacles" that surround the male spade connectors for the fan motor. One of these "receptacles" has a notch on one face, while the other one does not. It appears that this might be designed to accommodate a protrusion on one of the female spade connectors, to ensure that the correct female spade connector is plugged into each male connector. Alternatively, it could be designed to accommodate a single female connector containing both spade connectors, in which case the notch would polarize the connector to ensure it was plugged in the right way round. I am guessing that this is what Phil is referring to when he writes about a "lug" - i.e. something that engages with the notch in the receptacle. However, as far as I know (certainly the case with my car), the wiring loom to the motors just contains 2 leads, each with a plain female spade connector, with nothing to engage in the notch in the motor casing. Probably just another case where Jaguar saved a few pennies by not buying an unnecessarily special connector, when 2 spade connectors would work just fine....

-David

Dennis is correct in that when the AC is on the fans should run all the time--if the ac is not they should simply cycle as the Otter switch determines. Running the fans in all weather and all conditions at all times is unwise and counter productive for the engine temp as well as the life of the fans.

Pic was too big ---sorry

Guys,

Here is a photo of one of my fans. If you look closely you will see the "lug" for a wiring locator. Usually used to differentiate one wire from another.
Thanks!

Long answer to a simple question:
1) Your car originally came with series wound motors...there are two 1/4" connectors built into each fan chassis, and polarity doesn't count. These motors had a "square" cross section, and were painted hammertone silver.

2) Some vintage subtitutions used later Lucas motors which had permanent magnets. These are polarity sensitive, but again, there are two 1/4 inch terminals.

3) Aftermarket, anything's the norm. If you have a pair of Coolcats, then they will have 1/4 inch connectors on black and orange leads.

In the latter cases, polarity counts, but if you reverse, the fan will simply run backwards, no harm. One wire going to the fans is hot. The other wire goes to a relay contact: the other relay contact will be ground.

I have no idea what you mean by a "lug", or why your fans wouldn't have two connectors. A photo might help.

The relay should NOT be energized all the time. Even if you have A/C, the relay will only be on when the A/C is on.

If your car is air conditioned, the fans should run all the time. There are two relays on the front crossmember that allow this to happen. My Series 2 is air conditioned and was re-wired by someone to run only when the water reached a certain temperature. The car ran hot until I replaced the relays and allowed the fans to run continously.

If your fans are the square style, they are not polarity sensitive so the wiring does not matter. If the later round style, just hook up so that the air is sucked out of the radiator, not forward. The square box style motors are different from the Series 1 vs Series 2 cars so check to make sure they are running in the correct direction.