Citroen C3 cooling fan issue

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seanrx
Donor 2024
Posts: 168
Joined: 02 Feb 2017, 13:11
x 6

Re: Citroen C3 cooling fan issue

Unread post by seanrx »

Okay, there is two types of manual switch.

Overide. For cars with a normal working fan, but the driver wants to switch on from cabin also. So there is still ECU signal wires in loom.Track day types use it sometimes.

And just a manual switch, my car. If I removed fan, relay, wiring and battery and bolted to a steel table, fan will still work. Don't require the ECU. Relays are there to handle the power only.
I think a regular relay should fit in your car someplace.

Start a wiring topic here. I did three years back, lots of advice.
olimkd
Posts: 9
Joined: 09 Jul 2024, 12:09

Re: Citroen C3 cooling fan issue

Unread post by olimkd »

seanrx wrote: 18 Jul 2024, 19:10 Really?
So nothing in your fan wiring that's a sealed round/square plastic box with 4/5 flat pins sticking out downwards?
ooo yes . nothing. no classics 4/5 pins relay.
i traced 4 smaller pins from resistor, 3 wires are going to ECU, and one is splitting towards ECU and BSI. they are all good for resistance.
seanrx
Donor 2024
Posts: 168
Joined: 02 Feb 2017, 13:11
x 6

Re: Citroen C3 cooling fan issue

Unread post by seanrx »

Then you may have to manual switch as in my car. Depends how much you want to spend to find the ECU fault.

You write that fan does run with a d.c applied. That's a start.
My old fan did not.
The new fan did of course but was still no signal from the ECU. Pah! So I had to butcher £120 of new item for a manual switch.

Lots of diagrams online, easiest is using one wire to switch, like mine.
And a new battery pos clamp, a type that can accept other wires bolted onto it. From Halfords.