2000 V70R electrical issue continues

[manovlov]

... Started up car and all ran fine. Immediately I turned the light switch to sidelights the engine started running rough and the headlight fullbeam came on (should not be activated) as well as the front fog-light, engine check light and ETS and both direction indicator dash lights.

I continue to think it has to matter with a relay, or may be the relays braket could have suffered from the initial wrong plug in operation.
+1 with The Wize One : to control the wiring.

Manov

[scot850]

Battery is on charge but at 2A only as still connected to car.

My wife added that when this started when she was driving the speedo also went out as did the dash lighting.

Why can I never get easy fixes??

I am thinking it may be low voltage or charging that may be the route cause. Trouble is I need the lights to be on to run a load test on the battery and the alternator.

Neil.

[scot850]

Should add, I disconnected the headlight wipers in case they are an issue, checked the headlight internal wiring and other than one light missing the plastic connector (the 2 push connectors are just pushed in place but not shorting and must have been there the whole time I have owned the car). I do have spare wires pulled just in case these were an issue. My car still has those 2 add in wiring extenders that the later cars got.

I'll have a look through the wiring more closely but no signs of poop or other critter debris so far.

Neil.

[manovlov]

This came about when I had a mishap trying to re-fit the battery at -20C and a gimpy arm. Managed to somehow get the +ve and -ve battery cables to both touch the terminals at the same time causing a large fat spark. When I tried to start the car I got all sorts of weird dash issues when I tried to switch the headlights on.

I know that I am stubborn and that my knowledge is very far from the knowledge that you are becoming. But I have a hunch that the problem is related to the instrument cluster. There is an element that is damaged between the battery and the instrument cluster.

I don't know these Volvo series. But can you access the circuitry behind the instrument panel (which means you have to take the dashboard off)? Maybe a wire has become hot and is making contact with the body of the car. This could explain the anarchy that is triggered by the headlight switch. When turning, the vibrations make this cable move and cause these micro-cuts that make your handset mess up.

Have a look to where the wiring torrent crosses the engine compartment panel.

[scot850]

If the battery and charging system does not fix the issue, your suggestion is a good one and where I was thinking of going eventually. If I need to do that it can wait until winter when I plan to pull the whole dash anyway to fix the mounts that squeak.

I understand what you mean. What does make me doubt it is that it takes a lot of power being drained to the dash cluster which I just don't think it uses. Also the issue only starts once the lights are switched on so far. If the lights are left off the car runs fine and everything else works ok.

These 99-00 cars are really sensitive to low voltages/current. The battery is still under warranty so that will be on the list to do.

Thanks for your info. Always appreciate help!

Neil.

[BEJinFbk]

Welcome to SEATAC!
With the opportunity of a long layover,
I dug a little further into just one part of
this little gem - The Turn Arrows.

You could be seeing the result of a ground
that they share being poor or open. It looks
like they share a ground on the 31/50 ground
bus on the interior bus panel below all of the
relays on the interior firewall. Reseating that
connector might do the trick.

Also, the 31/50 bus appears to be fed by the ground
point on the driver’s fender behind the air box, 31/52.
If you’ve already checked it and it seems OK, then
checking the multi-pin ground bus connector seems
worth the uncomfortable reach.
.

.

.

.

[scot850]

Tanks to all, and particular our man from the great white north BJ.

Appreciate all the wiring diagrams, and as I have said many time, electricery is not my strength.

So, here is the latest update, basically zero progress.

I charged the battery at 4A for 36 hours and then took it off charge and let the battery rest for 3 hours. 13V dead on.

Started car, all good. Tried lights switch, back to the same old crap and rough running.

Checked the grounds I can easily see. The one at the battery I removed maybe 9 months ago, cleaned it to shiny as well as the bolt and touch point on the inner fender. Still in same condition.

Checked the ground under the LHS (DS) dash area above hood release. Picture below. Nice and shiny.

LS ground under dash on inner fender

Figured out how the multi-plug worked and disconnected. No signs of rust or burnt connectors. Re-installed.

Multiplug on DS disconnected

Pin side of multiplug

Socket side of multiplug

Found a random toggle switch by the multi-connector I have never seen before (see pictures). I tired flicking back and forward a few times in case it had stuck internally. It was set to ON anyway. I love random stuff like this ( )!! It has 2 small black wires running from it up under the dash somewhere. That will have to wait until dash is out over the winter, assuming it is not dumped in a field and set on fire by then!

Random toggle on-off switch

I spent some time poking around but cannot see anything obvious shouting 'I am fried'!

I have not reinstalled the battery and tried it again yet but as I found nothing, assuming there will be no change.

I was planning to swap the electrical part of the ignition switch. Part number is different again to the 2 I have. One is a brand new part that is supposed to be for my car and most P2's. The one I pulled from the 99 S70 (no idea if original) is an alternate part for the newer one. New part # 8650054. Used part from 99 S70 # 9459503. Part fitted to my car: 8645228.

Latest part on the 'R' is 8645228 which I cannot find an alternate part for, but on Ebay it is listed for P2's. Can I assume safely that as the others 2 I have are also alternates for P80/P2's that this is as well?

I'll pull the Vida PC out and wind it up and check part numbers.

If the part number turns out to be compatible I will swap it out for giggles.

I spent some time trying to interpret the wiring diagrams looking for possible points of commonality. If I am correct the 5 parts I can see are:

1) The DIM (Dash speedo unit with warning lights)
2) The ignition switch
3) The hazard warning switch
4) Turn/cruise switch
5) Electrical portion of the ignition switch.

I think I have alternate new/used parts for 2-5 but not for #1 as I don't know if you can even swap these without coding from dealer is at all?

But then why any of this makes the engine run rough when the headlight switch is turned even to sidelights, is beyond me.
Also the dash lights are really dim except for the ones in my last post. The majority are barely legible as so dim.
Why do the lights for the turn signals both come on really bright as well as the Engine check light, fog-light indicator (front) and full beam. The last 2 items are not even switched on? Also when this happens the ETM doesn't switch off always after the rough running. Requires key turned to II and back to 0 to switch it off. If the ignition is off where is the power coming from?

Again, any help appreciated.

Neil.

[abscate]

Oh my. That switch is not good. Figuring out someone else’s wiring is never fun.

Have you monitored the voltage going into the ETM when your turn on the lights ?

You should be past the chassis break for the P80 ignition switch so the later one is what you want

[scot850]

Thanks abscate. I have not measured the voltage to the ETM when switching on the lights. I would if I had any idea how to. Can you inform the ignorant?

Can you use Vida on the car when running? I have only ever used it at ignition position II

Naturally I can test with Vida in position II and see what happens when the lights are turned onto sidelights/headlights and if the same things happen with the dash?

Maybe our friend Manov has something with the DIM. As why does the speedo drop out?

I am rapidly getting further out of my depth. Methinks tomorrow I will try checking if anything shows up with Vida. If I see nothing to make me any the wiser, I will try swapping the parts listed before and see if any make a difference. If no improvement, then it is on to the Dealer electrical expert.

Neil.

[manovlov]

Ok. To give my electrical car level, i need a wiring to understand where i am and where i go. But, your story makes me dig into my head. I recently looked to our friend Ed China. He was figure out with a issue that looks a bit like your, and the guilty one was the regulator. I'm so stupid about this car i had to download Skandix Catalog to be sure there was one on your car, it's to say. No shame, but the pleasure to learn something new. Well played, Manov !

Neil, i think you should have a look at his video. It may help you to succeed to fine the issue origin, at less i hope so.

Manov.