1998 v70 Intermittent headlight probs & now dies occasiona

[guitarguy]

Hello All,
This is my first post here, although I've learned a few things already from reading older posts, so thanks for the help with previous issues.

I have a 1998 v70xc turbo wagon - 366k miles - I've only owned it few months, but it was very well maintained by the original owner and I knew the previous owner, the body is in GREAT shape and it seems to run very well, over all... so I bought it, mostly to haul around some small music gear.
(that last line should imply that I am NOT a mechanic - but I can usually read instructions or watch videos and do most of my own small repairs) For a few months it has run pretty well, but I've had a few strange little things.. master control (driver's door) for rear driver's window(new master module installed when I bought it) doesn't work sometimes - indicator (prndl) light by the gear shift comes and goes - one bulb in dash is out. - - I haven't fixed the fuel gauge yet - that's about it.

Recently I changed plugs, wires, etc.. and in the process, found a hole in the turbo coupler, so I replaced that , which apparently increased the 'power' or 'compression' enough to cause it to blow loose an oil cooler line, from the radiator (which the previous owner had replaced) ... got that put back together and put some clamps on the retainer clips, etc.. Obviously, this threw a fair amount of oil around the front passenger-side area behind the headlight, which I wiped up the best I could. - It happened a block from my house, so thankfully no overheating from oil loss or anything.

For the first 2 or 3 weeks ( it doesn't get driven daily) that didn't seem to harm anything and it ran like a top... then toward the end of 60-70 mile trip (but only 5 minutes after being briefly stopped and restarted ) the headlights dimmed... then came back up to 'normal' - this continued all the way home - almost every time I'd take my foot off the accelerator and especially when followed by stepping on the brake, the headlights and at least most , if not all, dash lights, would go pretty much completely out... and then come right back up.

I made it home with no real problems (other than nerves) - tested the battery and alternator with a volt meter - everything checked out fine ( battery fine - alt. charging at 13.6, I believe )
Also ran OBD-II scan and found nothing except an evap emmisions code, which had already been there.
and , of course, after being shut down and restarted it was no longer showing any symptoms.

A couple days later ( after running and lighting fine a few times ) the same thing happened... same basic scenario - let off gas , lights dim then come back up. - This time I simply pulled over, shut it down , restarted and drove home with no problems. tested everything again... still looked fine.

Since then the 'pattern' continues.. runs fine a few times, then has the same issue... restart.. does fine .. eventually happens again ... However - on a couple recent short trips it started up and immediately just shut off- no sputtering or rough running.. just died - fired right back up and ran fine... drove it home and at least once, while parking - it died again the same way. Battery and alt. still testing fine.

Has anyone had a similar problem? any ideas what component(s) I should be looking at ?
relays, fuses, etc, which may have been affected by the oil or the possibly slightly improved power from the recent 'tune-up'? anything else? -

Any good advice would be greatly appreciated. - Thanks for taking the time to read !!
Thanks again for the forum.

[Ozark Lee]

I think I would start with the battery cable, particularly the connection that stubs off of the main cable to the fuse box. That connection can get loose or corroded and it will have exactly the symptoms you describe. In some cases it can be the other end of that cable where it goes into the fuse box that has overheated.

The electrical portion of the ignition switch could also be a problem but there is usually more intermittent weirdness than you describe when that is failing.

Start by cleaning and tightening all of the battery connections.

...Lee

[cn90]

1+ to ignition switch, about $50 at dealer.

The issues of start then dies without error codes:
- Could be bad fuel relay, search forum for the trick jumping terminal 15 and 87.
- Could be bad fuel pump, especially at that mileage. If you decide that the fuel pump is bad, stick to Bosch 69693 (search for the posts by "stephansvolvo").

[guitarguy]

Thanks Lee and Cn for the responses

I had seen the ignition switch mentioned in other posts, but wasn't sure I had all those issues.

Fuel relay was changed just before I bought it, because it was 'sticking' in cold temps and not starting .

Battery connections look good and no visible corrosion anywhere, but I'll check the other connections Lee mentioned.

Seriously hoping it isn't the fuel pump , because of the scary stories I've already read, when researching the fuel gauge on AWDs for this year/model ( the access panel leads to nowhere, drop the rear suspension, etc.) , but I'll probably be going there eventually, either way.

I'll be checking things and looking for other replies and will report back any progress or discoveries.

Thanks !

[Ozark Lee]

Seriously hoping it isn't the fuel pump , because of the scary stories I've already read, when researching the fuel gauge on AWDs for this year/model ( the access panel leads to nowhere, drop the rear suspension, etc.) , but I'll probably be going there eventually, either way.

Since I have changed two of them in the last month I've got the process down to a 2 1/2 hour job start to finish.

The fuel pump problems, however, are inconsistent with the dimming headlights.

...Lee

[abscate]

I think lee is right on a bad ground. There are a lot of grounds on these cars, which are small braided straps that corrode and need maintenance

[guitarguy]

Thanks again for the replies... taking my time and looking things over as far as connections and everything - like I said, I don't drive it everyday or anything... but I'm still tending to think there's a component causing this... because of the fact that when it happens , I can shut it down , start it up and be fine for the next few trips.. it seems very much like 're-booting' a computer, to me. - I'll be watching for more ideas and updating if I find anything.

[guitarguy]

just updating - Had a few other issues (door check, etc) to deal with - So far, all I have really done with regard to electrical to is wiggle and scrape around a few wires which had the tiniest amount of white 'corrosion' or 'scale' (barely visible) - I drive it so rarely that it's very hard to know if this helped, being such an intermittent problem to begin with. but in the last month the dimming problem has happened once.. and it hasn't died. most of the trips , however, have been very short. - still keeping an eye on it.

[rmmagow]

There's a "B" cable that needs to be thoroughly checked, easy fix. But, this could be just the voltage regulator getting tired. It is easy enough to change and could be giving intermittent issues that won't show up on a single test. My lights flickered and this is what fixed that for me.

[scot850]

The B+ cable is the smaller red cable running from the battery +ve to the main fuse box (the kidney shaped fuse box in front of the brake booster with the 3(?) spring clips holding the top in place). Open this up and look at the front corner of it for the B+ cable where it comes in and is held down with a nut. If the brass is shiny chances are it is good. This was/is a problem more on 99-00 cars. My 98 and others I've seen weren't affected by this.

At this mileage changes are it is the alternator or at least the voltage regulator failing. The carbon brushes can stick and be intermittent.

Finally, check the positive cables from the alternator to the starter and starter to the battery. One of my cars I found the cable had been damaged internally (previous owner didn't remove this when dropping the sub-frame and jacking the engine I guess).

If I missed it, then the other suggestion about the ignition switch is another area I have had strange faults happen. Had to replace on 2 V70's last year both with about 160k miles on them.

Good luck!

Neil.