05 XC70 high beam relay - CEM

[Faust]

As posted before, I don't have high beams. Although I get blue high beam indicator on dash. I switched out the combination switch on the column (interestingly I got my DIM back, for about 1/2 an hour, now gone again) In any case, I don't seem to get any power at the high beam fuses. Looked for a relay, and can't find one. My "search" seems to indicate that the relay is in the CEM. Is that the case? Do I have to replace the CEM? It is noteworthy that the PO jury rigged power to the fuses, I don't know for sure that this ever worked, pictures attached. If I replace CEM is "reprogramming" required? Car came with records indicating extensive service over the years. If someone jury rigged wiring, this was probably an alternative to a very expensive repair.

If I tried a used CEM, are there "numbers" to look for? I notice the combi switch I replaced (which is "obsolete) required me to pull 5 out of boneyard XC70's before I found one with a number matching mine. If I understand, they are specific to cars with "trip computer". The number on mine is 30669738, don't recall more common number but ends in 097.

Can anyone explain where I can get VIDA. I seem to recall it is available rather inexpensively. I took my car to local "Swedish Car Specialist", he tells me he dropped VIDA because he could no longer afford it and recommended the dealer.

[darrylrobert]

Looks like there is a wiring problem between the Cem and the cabin fuse box or your cem is faulty?. You need to 1. find a wiring diagram 2 use a multimeter and start checking wires for continuity. This can be done without a wiring diagram but "sometimes" they change wire colours mid run.

[Faust]

Looks like there is a wiring problem between the Cem and the cabin fuse box or your cem is faulty?. You need to 1. find a wiring diagram 2 use a multimeter and start checking wires for continuity. This can be done without a wiring diagram but "sometimes" they change wire colours mid run.

It appears to me that the CEM and the fuse box is a single unit, or very closely connected. Unlike, 04 and older, the headlight relay is NOT mounted externally on the CEM. Removal of the CEM, for a better look, is quite a job. What I am having difficulty with is whether the fuses are supplying power to the relay, or transferring power from the relay. 10amp seems slight if they are suppling power to the headlights, and the wire seems small gauge. Because of the way the wires are encased, I am having difficulty determining which wires are which. What is being shown in the pictures is power being taken from the dash end fuse box, and then supplied to the headlight fuses, which are mounted on the CEM. I am having difficulty reading the wiring diagrams I have found.

An interesting note. In the boneyard I visited today, more than 50% of the Volvos had been stripped of all electronics. By that, I mean "everything". Fuse boxes, modules, switches, etc., etc.

[Faust]

Well, I decided to replicate the PO's "jury rig". Running power to the fuses produces high beams, so everything South of the fuses appears to be working. North of the fuses, the combination switch appears to be good. Therefore I suspect it is the relay in the CEM. I understand this to be a repair (having CEM rebuilt) totaling around $600, and disabling the car for about two weeks. Am I correct in my understanding that if I install a used CEM, I still need to get it to the stealer for "re-programming"?

[abscate]

Yes.

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Yagger here on this forum