Saxo radiator switch

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Jonathancilia
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Saxo radiator switch

Post by Jonathancilia »

Hi i recently went to the parts store and bought a radiator switch and gave him the car vin number so the part will be good. But when i went to remove the old one i noticed it has 2 pins and new one has 3 but connector fits exactly, fan on this car doesnt run much so im concerned that it will not come on and overheat. It is a 1.5 diesel.

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white exec
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Re: Saxo radiator switch

Post by white exec »

Let us have your VIN, and we can check it out.

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Re: Saxo radiator switch

Post by Jonathancilia »

Im not from UK will it work anyway?
Last edited by Jonathancilia on 16 Jul 2021, 11:52, edited 1 time in total.

wheeler
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Re: Saxo radiator switch

Post by wheeler »

Yes it will work even if not from UK

Jonathancilia
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Re: Saxo radiator switch

Post by Jonathancilia »

VF7**************[VIN obfuscated, can be read by forum staff]

Jonathancilia
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Re: Saxo radiator switch

Post by Jonathancilia »

I bought another one with 2 pins for peac eof mind, at the moment i have some air getting into the diesel aswell, replaced the injector return lines because they were cracked but problem is still there, starts fine when cold but when at a stop the idle jumps up and down slightly, kind of annoying.. i heard that it could be the diesel filter housing getting porous, maybe?

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white exec
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Re: Saxo radiator switch

Post by white exec »

Apologies, Jonathan, for not coming back on this sooner.
For the Saxo 1.5D, it has a single fan (twin fans for Hot Countries), and a 2-pin radiator thermo switch, 97°C on / 92°C off, for the single 120W fan.
Same switch fitted to good few other PSA cars.
The item is available from Citroen still, and half-a-dozen aftermarket ones on Mister Auto (and elsewhere).

(The 3-pin one is intended for twin fan two-speed fan installations, and operates at 101/96 as well as 97/92°C.)

There is also a relay shown near the radiator, presumably going between the thermo switch and the fan.
Sorry, but I don't have a Saxo circuit diagram handy. You may have one already (eg Haynes).

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Re: Saxo radiator switch

Post by Jonathancilia »

Dont worry bought the proper one now for it. Thanks for the info though, the diesel priming bulb is a check valve? I had a look at the pipes connecting to it and the inlet seems a nightmare to get to as it seems to go inside the car.

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white exec
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Re: Saxo radiator switch

Post by white exec »

All the fuel supply pipework up to the injection pump operates under suction — the injector pump draws fuel from the tank on diesels, where it is pumped from a tank-fitted pump on petrols. So on diesels, you'll not likely see any leak, but air can get sucked in.

Common air leaks are hose joints (always use genuinely circular hose clips, not jubilee/worm types), and the fuel filter itself.
The rubber priming bulbs can also go leaky - replace or temporarily by-pass. The priming bulb does contain a non-return valve, so it only squirts one way.

To test for air in fuel, temporarily replace a section of the pipe with a length of clear plastic hose (start where the pipework arrives at the pump, and work backwards, towards the tank). You should be able to see any air in the fuel; there should not be any.

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Re: Saxo radiator switch

Post by Jonathancilia »

Since i replaced the injector return lines i dont see air in the clear pipe anymore but the priming bulb when pumped goes hard then goes soft after a few seconds.

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Re: Saxo radiator switch

Post by Jonathancilia »

Most of the pipes are barbed and heat shrinked onto fittings, i cant just replace them without destroying them

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white exec
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Re: Saxo radiator switch

Post by white exec »

That's normal for priming. When you pump it goes fairly solid, but this build-up of pressure fades away pretty quickly when you stop.
The priming bulbs (or filter plungers) are only there for emergency priming purposes, and don't actually do anything (except let fuel pass through) during normal running.

Good that the air has disappeared.

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Re: Saxo radiator switch

Post by Jonathancilia »

But before this issue it used to stay hard all the time, and the idle pulsing is still there

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white exec
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Re: Saxo radiator switch

Post by white exec »

Replace the primer bulb with a new one. Possible that its non-return valve has gone leaky.

Check the idle speed adjustment on the pump (there are clearances to the stops to be got right), and check also that there is a tiny bit of slack on the main throttle cable where it attaches to the pump. Important that the throttle cable "tightness" is not responsible for the idle speed, because engine movement will then affect it. If the pump has a cold-start mechanism too, check the clearance on that too.

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Re: Saxo radiator switch

Post by Jonathancilia »

Thats my plan , the hose from the primung bulb to the fuel filter is no problem its rubber, but the inlet pipe from tank to the bulb its like plastic and it continues to the inside of the car it seems