Twin Fan Relays And Uprated Rad

[Mr Teflon 1 1 Cars]

Hi All

 

Had a couple of cooling concerns on the last trip - and only managed 5 laps of Cadwell on Thursday before I resigned myself to having a tinker around with the Mi.

 

Figured a new rad couldn't hurt as the one on the car looked original - and I killed a 5 Turbo once by changing everything but the rad that turned out to be 80% blocked - so off I toddled to the local motor factor.

 

I asked for an alloy cored rad, explained why and the chap came back with 2 options.

 

Standard rad with a 35mm core.

'Uprated' rad with a 44mm core.

 

Naturally, I took the 44mm and fitted it today. I did ask my father (40 years with PSA) why there would be the 'uprated' option listed at a local factor and he told me it was most probably an export spec rad.

 

 

Slotted in nicely.

 

 

Only thing I'm stuck with are the relay arrangements behind the front grill. 3 relays for 2 fans ? Only a Pug!

 

 

By grounding out the thermo switch contacts I can get one fan running fast, both fans running slow but not both fans running fast! Which is what I want instead of just one fan cutting in when the car gets to temp as it does now.

 

Should both fans be running fast when they cut in? and which relay is at fault on my car if so?! And why is there a slow setting?

Help welcomed

[ryan13961345402285 1]

If your car has air-con then unplug the Bitron sensor (brown multiplug screwed into the bottom of the thermostat housing). This fools the system into thinking there's a fault with the sensor and hence it puts both fans on full as a failsafe measure.

While you're at it unplug those relays, clean the contacts and put some silicone dielectric grease in them

[petert1345402284 0]

There are three relays for a reason. 205's are the same. The fans are connected in series for low speed, then in parallel for high speed.

[petespug405mi16 0]

now that looks good how did that rad cost?

[KRISKARRERA 2 1 Cars]

Something isn't right because you should have both coming on at high speed.

(just to state the obvious! )

Edited July 1, 2007 by KRISKARRERA

[Mr Teflon 1 1 Cars]

The rad wasn't cheap - but I figure it's worth it given the use the car gets subjected to! LOL

 

£140

 

When I get a minute I'll swap the relays around to see if I can identify one that's faulty (Unless someone can tell me which one is most likely to to control the high speed settings for the fans?). If the issue remains as described I know it will be a wiring matter - possibly to or from the relay that controls the high speed setting.

 

Should be taking it to Brands Hatch tomorrow for a shakedown - it needs to be right as it's off to the Ring for the weekend

[Mr Teflon 1 1 Cars]

Sorry, meant to say no aircon ...

[Mr Teflon 1 1 Cars]

Cooling sorted - good thrash round and no problems

 

I'll sort the fans over the next couple of weeks.

[Guest turbolag]

Hold on a mo...my (non aircon) phII has only 1 fan. Is this normal?

[KRISKARRERA 2 1 Cars]

I can't answer - not familiar enough with the phase 2. Maybe they decided 2 fans was overkill.

[Guest turbolag]

It's got the mounting hole for a second fan, but i just assumed that this was where the aircon fan would sit, but if other Mi's had 2 then maybe I should have. Either way, a second fan slipped into my hole (oo-er!) might be an idea. The existing fan is also switched, so i can whack it on before things get too bubbly.

[Mr Teflon 1 1 Cars]

If anyone is thinking of uprating their rad I can tell you that this 44mm core kept the temps rock steady even after 6 back to back laps of the 'Ring, always with at least 3 people in the car in a hot ambient temp

 

Well chuffed - the car only gets 'hot' when idling now, must sort that second fan

[KRISKARRERA 2 1 Cars]

Look at the pics I can see they are the thick radiators like in the GTi6.

[Guest serrento405]

Look at the pics I can see they are the thick radiators like in the GTi6.

<{POST_SNAPBACK}>

 

 

your new rad is the same as mine,and my car is a 2L with air con,fans normaly bad relay or bad Bitron sensor mine plays up and all connections are good ,it just plays up now and then on my list to sort i no it,s the bitron box non air con 2L only have one fan

[Miles 331 1 Cars]

The Rad is just a std Rad with car's fitted with A/C, Non A/C one's are the thin one's,

Not sure about the fan number, I know every Mi16 I;ve had always had 2 fan's but all had A/C fitted.

[Guest turbolag]

Mi phII has only 1 fan, but is a non aircon model. A second fan is on the shopping list for the future.

 

thanks for the heat exchanger info the other day - it's all on hold now until i've got the brakes and back end sorted...