No Supply To Radiator Fan Relays?

[GSMGuy]

Hi all,

Wondering if anyone has come across this before?

My 08' 2.0Hdi had the A/C regassed yesterday after I replaced the (holed) condenser, the A/C was inop when I purchased the van last week.

Anyway, A/C is great now - BUT I noticed that the radiator cooling fans were not coming on at all when the A/C was on, which they should do. So a bit of investigation revealed the following;

• Both fans work fine when connected direct to 12v.
• Both fans earths are sound.
• All 3 relays in pack fixed to slam panel operate as they should, opening and closing with A/C demand.
• There is no 12v supply to the "switched" contacts on any of the relays.
• Supplying the "dead" side of the relays with 12v, causes the fans to operate perfectly, switching on and off with the relays.
• I've also got access to a SnapOn Modis Ultimate, and although I can operate the fans via OBD, just the relays close, no fans actually spin as there is no 12v to the relays.

So, I'm thinking there must be a fuse somewhere that covers the main high current supply to the fans, but where, I cannot fathom. I've downloaded every workshop manual and wiring diagram I can find, but cannot see it..

Anyone got an idea where I should be looking?

Thanks in advance for any replies..

Mike

Edited December 20, 2015 by GSMGuy

[paul.h]

Have you looked in the handbook for a fuse list ? If you do not have a handbook these can be read/printed/saved in sections from  http://service.citroen.com/ddb/  and you will need to select your language.

 

A quick look in one suggests the engine fuse box, fuse 1, 20amp is for the fan assembly but also the ecu, fuel and air systems so if the fuse has failed these would also be affected. Maybe you could follow the wiring back from the fans to the fuse box and check for any damage.

[GSMGuy]

Have you looked in the handbook for a fuse list ? If you do not have a handbook these can be read/printed/saved in sections from  http://service.citroen.com/ddb/  and you will need to select your language.

 

A quick look in one suggests the engine fuse box, fuse 1, 20amp is for the fan assembly but also the ecu, fuel and air systems so if the fuse has failed these would also be affected. Maybe you could follow the wiring back from the fans to the fuse box and check for any damage.

 

 

Hi, yes I've checked the handbook, fuse 1 is for the fans & ECU etc, BUT it's for the "low current" supply that activates the relays, what I'm looking for is a fuse for the high current side of those relays, which I would expect to be around at least the 50amp size..

 

Mike

[paul.h]

Citroens usually have a set of maxi fuses hidden under the top layer of normal fuses in the engine fuse box. These are not listed in the handbooks but are often noted in manuals. As an example, in the C5 Haynes manual wiring diagrams for the fans it shows maxi fuse MF1 with a direct feed from the battery to the fan relays. It does not give the fuse rating though. To find them you may need to undo a nut or clip so the top fuse layer can be lifted or maybe there is a separate small fuse box - on the latest C5 there is a hidden one at the side of a front wing.

 

It would make sense if a maxi fuse has failed since the fans work with your temporary supply from the battery. Maxi fuses do not normally fail but we had one go for no apparent reason on a Picasso so it could have been a weak fuse.

[GSMGuy]

Thanks, there are a few maxi fuses in the engine box, look like a pain to get to though :(

 

Mike

[GSMGuy]

Well, looks like I might be getting somewhere..

 

Bought myself a cable tracer from Ebay (£18) and traced the relay feeds back to the under bonnet fuse box, where they are attached to a separate block;

 

http://i63.tinypic.com/50qfjl.jpg

 

Pulling this forward reveals that it has fusible links front &P rear, which appear to have well, fused...

 

http://i66.tinypic.com/34ywfg0.jpg

 

Replacement is £100+ from main stealer, so bagged one for £22 from Ebay:

 

http://i64.tinypic.com/35ksoz8.jpg

 

Will test fans individually first to make sure they are not shorted, hence the excess current..

 

Pics attached of box/links.

 

Hope this helps others!

 

Mike