Kenlowe fan relays
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Discussion

CAPP0

Original Poster:

20,836 posts

232 months

Tuesday 24th April 2018
quotequote all
Whilst not exclusive to Classics, I guess that aftermarket Kenlowe fans are more likely to be fitted to classics, hence asking the question here!

My v8 Defender has a pair of Kenlowe fans fitted, which were on there before I bought it and by the look of it have been there some time. Generally the fans don't cut in very often, if at all, but they were required last week and one of the fans decided not to play. When I had a look, it seems that the relay is sticking - a sharp tap brings the fan back to life.

It turns out that Kenlowe themselves don't deal with the public/aftermarket sector any more, so I can't get any help from them. Does anyone have any idea what spec of relay I would need to replace the dodgy one? At a guess I'd say a 20A normally-open would do the trick, but wondered whether anyone actually knows the spec, or has a relay they could read the details off for me?

Thanks.

Edited by CAPP0 on Wednesday 25th April 10:52

lowdrag

13,181 posts

242 months

Wednesday 25th April 2018
quotequote all
I can't answer your question, but every time i see anything about aftermarket Kenlowe fans I ask - are they attached through the radiator matrix? If so beware. They chafe and create leaks.

CAPP0

Original Poster:

20,836 posts

232 months

Wednesday 25th April 2018
quotequote all
lowdrag said:
I can't answer your question, but every time i see anything about aftermarket Kenlowe fans I ask - are they attached through the radiator matrix? If so beware. They chafe and create leaks.
I don't think mine are but I'll check. I've had it several years now and not noticed any issues/noise.

Yertis

19,707 posts

295 months

Wednesday 25th April 2018
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I'll have a look at mine tonight – I don't think the relay is anything special, just the usual Durite box. I guess they might vary from application to application. Regards Lowdrag's comment re fixing, mine is bolted up next to the rad on a couple of stout brackets. But I've seen some really dodgy Heath-Robinson Kenlowe installations over the years, so someone fixing through the matrix wouldn't surprise me.

lowdrag

13,181 posts

242 months

Wednesday 25th April 2018
quotequote all
Kenlowe supplied them with plastic ties which you threaded through the matrix and back again. A disaster waiting to happen. I have a Cool Cat on the E-type which bolts in place of the two-bladed windmill, and which moves 2,000 cu/ft per minute. And far cheaper.

HealeyV8

451 posts

107 months

Wednesday 25th April 2018
quotequote all
I'd get a 30amp five pin relay, these are pretty standard so relatively cheap Bosh is a good make.

CAPP0

Original Poster:

20,836 posts

232 months

Wednesday 25th April 2018
quotequote all
HealeyV8 said:
I'd get a 30amp five pin relay, these are pretty standard so relatively cheap Bosh is a good make.
What's the 5th pin for? The relays on mine only have 4, two for the coil and two for the contacts?

paintman

7,860 posts

219 months

Wednesday 25th April 2018
quotequote all
On my 3.5EFi RRC.
Still fitted with its original single relay which is a Lucas SRB525.
Relay connections:
30 is live in
85 from thermal switch
87 live out to both fans - instructions are quite specific that the wire to each fan is to be crimped together at this connection,
86 is earth.

Terminal 87a isn't used.

Fans must be fitted with the cable entry point between 4 & 8 o'clock as it also acts as a drain & breather.

Mine are the type that come with a DIY rod & clamp affair & make no contact with the radiator.



Edited by paintman on Wednesday 25th April 17:38

CAPP0

Original Poster:

20,836 posts

232 months

Wednesday 25th April 2018
quotequote all
paintman said:
On my 3.5EFi RRC.
Still fitted with its original single relay which is a Lucas SRB525.
Relay connections:
30 is live in
85 from thermal switch
87 live out to both fans - instructions are quite specific that the wire to each fan is to be crimped together at this connection,
86 is earth.

Terminal 87a isn't used.

Fans must be fitted with the cable entry point between 4 & 8 o'clock as it also acts as a drain & breather.

Mine are the type that come with a DIY rod & clamp affair & make no contact with the radiator.



Edited by paintman on Wednesday 25th April 17:38
That's interesting, mine are definitely wired separately via two relays. The feed from the thermal switch must be common I guess.

Perhaps I can just do away with one of the relays then.

TooMany2cvs

29,008 posts

155 months

Wednesday 25th April 2018
quotequote all
CAPP0 said:
HealeyV8 said:
I'd get a 30amp five pin relay, these are pretty standard so relatively cheap Bosh is a good make.
What's the 5th pin for? The relays on mine only have 4, two for the coil and two for the contacts?
One's normally-open, one's normally-closed. Four pin would do for a fan, but definitely bog standard relays would be just fine.

If there's two fans, you can relay 'em separately (each relay switching one fan) or jointly (one relay switching both). Obviously, the relay's gotta handle twice the current if they're joint. The other possible for two relays would be if it was a two-speed fan.

88v8

116 posts

227 months

Thursday 26th April 2018
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They draw a lot of current. Notice how the engine slows when they're running? I'd stick to two relays.

V8

paintman

7,860 posts

219 months

Friday 27th April 2018
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The argument for keeping them separate is that - as you have found - if one relay or fan fails the other should still operate.
Not a lot of extra wiring.