GUIDE: Repairing the wiring loom under your radiator

[chb]

Thing is though, the loom never looks rotten.
It blows in very isolated, separate locations that should cause bits not to work.
In my experience it was the wires carrying higher current that went (main ignition feed and ABS feed...oh and lambda heater feed). In each case this caused either a light on the dash, or total failure of the car to start. Any of these are point to raise if buying a car.

It is an easy fix if you follow the guide.

[v40bart]

That happened on mine too. Weird stuff was the fog lights not working and dash bulbs and head light bulbs blowing all the time. The culprit was a fog light feed wire that shorted on the radiator. Ahh, good ole V40, I miss it sometimes...

[kes1907]

Just wanted to say thanks again for a really useful post. I got under the car yesterday and sorted out the front loom. Thought it was going to be a nightmare and volvo wanted the equivalent of a kidney to do it for me. A couple of my wires were chaffing and had shorted. Quick re-splice and re-wrap = good as new.

ALL my annoying electrical faults inside the car have dissapeared. Lights all wqork as they should, no trip and clock re-set everytime you switch the ignition of and I dont think I'll miss the random warm flashing glow of the door open light on the dash even when every door is shut and locked.

[JSeaman]

Excellent news, well done!

[ravennexus]

does this only apply to pre2000, i have a 2004 V40 with o2 P0141 code and airbag lights on. changed rear o2 but light comes back on!!! so i guess it has to do with the wiring somehere, car had a front end bump was cat see and the lower rad support was bent in the crash.

[gatos]

Yes it applies to all S40/V40s from 1996-2004. However the O2 sensor has nothing to do with the loom under the radiator.

With regards to the SRS light, it is possible that the impact sensors have been damaged and you need new ones. I will check and get back to you about it

[gatos]

Had a quick look in Volvo VIDA and it seems that there are 5 sensors in total.

The collision sensors for the SRS system (4+1) are located in the B-posts, C-posts and in the SRS control module.
The collision sensors control the SRS system.

So my guess would be the SRS module which is under the centre console. However, if you want to be sure, then you should get the codes read and get back to us here. If the code SRS-0001D then that is definitely a shot SRS control module

[piperdave]

This happened to me...I locked the car to go on holiday, returned to find a very dead car. A visit to a local auto-electrician, and one to Volvo, got the car running again, but not alll things worked. The Volvo tech would not look at it as someone had worked on it before, to get it running, so the wiring wasn't" original". He told me to look under the radiator.

I wish i had found this post before.

I have limited mobility, so couldn't access it from underneath, so had to completely remove the rad from above to fix it. Took all day.

When i got it out, this is what i found....



....eight wires damaged.

Did give me the chance to replace the bottom hose clip though :¬))

Good post OP, thanks.

[twilightflyer]

If you guys want to replace like for like with the cables then try this place they can supply all cables in all sizes in metre lengths

[hjng]

u r lucky just sensors cable! mine cable at wiper storage area causing fire hazard!!!