I overcharged my xc90 and now it wont start,electrical problems

[volvochesterct]

I guess the moral of the story is to buy a newer smarter charger thats shuts off if you forget and leave it on for my next volvo

[volvochesterct]

I guess the moral of the story is to buy a newer smarter charger with auto shutoff for my next volvo

[matthew1]

Yea, they're inexpensive as ever https://amzn.to/3xuaL7J

Sorry this happened to you. I'm following. The only thing I can think of is to contact the + terminal with the body (ground) to zero out any residual charge in the system. (Without the battery in the loop, on either polarity.) I doubt it will help given everything else you've tried.

[chitownV]

Let’s hope it’s just a coincidence and something simple like a worn out starter.

Whether it’s now or later, if you plan to keep this one or get a newer used XC90, it may help to get an OBDII scanner or VIDA. Even a cheaper $32 one from Amazon that uses Bluetooth and a phone app will help to read many of the engine codes and show live data. Should work on your van too. https://a.co/d/05qKI4Aj

Next time, try to avoid jump starting with jumper cables and another vehicle. With all the electronic modules, a voltage spike could cause damage. You mentioned CEM, but it could also be your ECM or engine computer.

Using one of the jump starter battery packs is safer. They also come nowadays with fault detection in case the cables are accidentally reversed as well as fusible links in case of overheating. https://a.co/d/09vLjfrP

Yes about the battery charger. Besides a 10A taking up space, the highest I go is ~4A with my CTEK which has options for AGM, smaller batteries, and reconditioning. Instead of a straight charge then shut off when it reaches ~14V, something like the CTEK will build up voltage/current and then draw it down in different modes. Well worth the safety and quality of charging. After buying 4 other trickle/float chargers in the last 15 years, this one performed the best for me. YMMV https://a.co/d/05AYA0df

Remember you can install a larger H8 size battery if you have an H6 one. The larger capacity can help if you need to keep the accessories on with engine off, like for playing & singing songs with kids while waiting for someone, or for charging tools as a carpenter.

Good luck with the diagnosis and repair

[Krons]

If it is diagnosed as just the starter should be easy for your mechanic to fit a new one. I’ve done two on the 5 cylinders and it’s a pretty easy job, right under the intake manifold.

[volvolugnut]

well my neighbor came over with a voltage tested and we reading 12.2 at the front of the car and 12.8 at the battery in the trunk. Starter fuse is good.
Im thinking a tow to the volvo mechanic may be in order next. Get a diagnostic and see what whats..If its a relay or some immobilizer function or something simple I will pay to fix but if its a costly CEM repairs with hours chasing gremlins I will say goodbye and use that money towards a newer used xc90. I did try to jumpstart it today no luck

OK, but what was the load when you made these voltage readings? Headlights? None? Ignition switch 0, 1, or 2?
The voltage drop seems high is there was no load. If so, you may have corrosion on the wiring or wire damage.
volvolugnut

[volvochesterct]

my headlights were on and ignition was at 2.

[volvolugnut]

my headlights were on and ignition was at 2.

OK. That seems reasonable to me.
volvolugnut

[ggleavitt]

"My sunroof won't open. My interior lights won't come on."
If this is still a problem, maybe see about fuses on the left side of the dash (11C block), specifically 12 and 13. Maybe have a look at the symptoms in this post- viewtopic.php?t=83377 in the meantime to see if anything resonates. Having the codes read will provide granularity to the fault but you can check the fuses as an easy first step.

[volvochesterct]

We used to go to european auto in old lyme for years but unfortunately john retired.They were the best.I live in chester ct-can anybody on here who might be from this genral area recommend a volvo specific mechanic to bring it to?or a mobile mechanic?thanks