Radiator relay/sensor question

[Piwoslaw]

While fooling around under the hood yesterday I found a relay/sensor(?)


It's a plastic box with a metal cage on one side. Inside the cage are a spiral and a resistor(?). The module is mounted in a hole at the top left of my radiator, with the metal elements facing (almost touching) the rad. Two cables connect to the box, one with 4 wires to the top and one with 2 thicker wires to the bottom.

I didn't have time to open the box, but I did check resistance between the wire tabs:
between bottom '1' and top '4' is 1000 ohms,
between top '1' and top '2' is 150 ohms,
between top '1' and top '3', and between top '2' and top '3', are both 75 ohms.
Bottom '2' doesn't appear to be connected to anything. I believe that when hooked up, the bottom '1' connects to the '+' of the battery (the mass in my car appears to be '+', not '-').

Can anyone help me understand what this is and how it works? Is this the thermostat for my fan? BTW, my fan is supposed to be 2-speed, 1 turns on at 95*C (or 85*C with A/C on), 2 at 105*C. The fan has a 2-wire connector, but doesn't hook up directly to this module.
I'd like to know how this works, hoping I can tap into the right places for a cabin LED and grill openning motor.

Thanks,
Adam

[vtec-e]

That is one trick looking piece of kit there Adam! It almost certainly is for your radiator fan. How it works is beyond me however. You could try talking to someone from peugeot or citroen but i doubt they'd tell you anything. I doubt even the mechanics know how it works, only if it does or not! If it's sending an analogue signal to the ecu, as you imply, then hooking it up to an LED etc. is going to be more difficult. Well for me anyway....! But if it switches on at a given temp then you are in luck. All you need is a circuit diagram...........

ollie

[vtec-e]

I found this site after a search using the part no. in your picture. It may or may not be of use to you. Strona 189 - Katalog części - Auto-Szrot - używane auto-części pochodzenia zachodniego

Best of luck!

ollie

[Piwoslaw]

Originally Posted by vtec-e

I found this site after a search using the part no. in your picture. It may or may not be of use to you. Strona 189 - Katalog części - Auto-Szrot - używane auto-części pochodzenia zachodniego

Wow, and it's in Polish Thanks, I'll have a look
I put something up on the Peugeot Klub forum, maybe someone will know.

[Piwoslaw]

I got only one partial answer from the Peugeot Klub forum, but I did find some electrical schematics for my car, and it appears that this module only regulates the speed of the fan. The coil is a thermoresistor, while the little 'resistor' just above it is supposedly a diode (though when checking resistance it was the same both ways).
The diagrams aren't exactly easy to understand, so it may take me a while to grasp everything.
If anyone want a crack at it please PM me.

--Adam

[vtec-e]

So it would appear to regulate the fan speed with the use of a variable resistor. This could be used to regulate how much a grille block opens. I'm not sure how so i'll leave it to the electrical experts here.

ollie