96 850 interior light problem

cet · Post by **cet** » 09 Jul 2011, 13:01

I recieved an early aquaintence with the crazyness of Direct Current in an automobile when my brothers 64 dodge dart would have the dome light come on when you hit the brakes, i now have something close on the Volvo. Fuse 15 will blow as soon as you put it in and any actuation of an interior light will cause the (the door is open the keys are in the ignition bell) to ring at a reduced volume. open the glove box or switch on any interior light and its ding....ding... anyone with a clue?

Post by **BEJinFbk** » 09 Jul 2011, 14:58

Find out what's blowing the fuse, fix it - No More Ding Ding Ding.
Here are the systems that get power through fuse 15:

: 96 850 fuse 15 systems.jpg (27.07 KiB) Viewed 5402 times

And this is where to get the complete wiring diagrams for your car:

https://www.matthewsvolvosite.com/volvo-wiring-diagrams/

Post by **Ozark Lee** » 09 Jul 2011, 17:34

My bet is that someone changed the sunvisor and chopped the wires without disconnecting the battery. That is where I would start my quest.

...Lee

tassieti · Post by **tassieti** » 10 Jul 2011, 02:18

I'm trying to sort out something similar on my C70 Coupe at the moment. Fuse 15 keeps blowing (at the fuse box there is 12v going in one side of the fuse and the other side is always grounded). I've disconnected all interior lighting and the thing still keeps blowing! I've narrowed it down to about half a dozen wires that cause issues, some don't even seem to be related but when connected cause other wires to ground out blowing the fuse.

I'd start by disconnecting all interior lighting and see if that helps, I hope for your sake it is!

valvster · Post by **valvster** » 10 Jul 2011, 04:38

Fuse #15 feed goes all over the interior of the car including the doors and the boot(trunk).
The ding ding will disappear once you have fixed the cause of the fuse blowing.
As Ozark said the sunvisor is the most likely place to start your search.... then any doors or
the trunk if you have had any accident damage and repairs.
If yours is a post October 1996 model it may have provision for wiring for alarm sensors in the trunk
under the tail lights that may be shorted to earth.
Mostly the wiring is fully protected in plastic tubing except just under the trunk latch, in the same location is one of those
plastic fasteners to hold the trim, this is where my fault was. The power aerial was replaced under warranty and the tech
had pushed the wire into the fixing hole with the fastener. Started out as an intermittent fault 6mths after I got the car in 2000, a year later it turned into a permanent fault and took the local Volvo specialist 12 hrs to find the fault....thankfully under warranty.

Good Luck,
Valvster

cet · Post by **cet** » 11 Jul 2011, 20:59

i have looked at the schematics for interior lights and seat belt/ key warning to the point of halucination, so all the suggestions are welcome.
Lee and BEJ, thanks for your help in the past, the schematics are much better than those i found on search and i can see why someone would want to chop the visor lights as my kids wiped out a marginal battery leaving them on.
I am going to pursue what Valvster has suggested (the systems seem to be the same in US and australian markets so the fix may be of help to Tassieti )
i have experienced a sticky trunk lock lately, will rip into there to check for a solenoid meltdown or other anomily, stay tuned!

tassieti · Post by **tassieti** » 24 Jul 2011, 22:14

Did you have any luck with this?

I'm pretty sure my issue is in the wiring loom that runs behind the dash (I removed wires from the connector block one by one testing for shorts), I went to remove my dash but I have a stripped bolt on my steering wheel so I can't remove it. I'm so frustrated at this point, the interior is in pieces and I can't stand to look at it

Post by **Red-Arrow** » 27 Jul 2011, 01:18

Sounds like a bad Earth.

cet · Post by **cet** » 12 Jul 2012, 23:48

Took some time but the quest is over. The drivers side light bulb in the cluster surrounding the rear view mirror had been inserted too far causing the metal case of the bulb to short circuit between the positive and negative contacts. I have experienced a number of light fixtures from Cibie and Bosch going back to the 140 model and have never encountered a more poorly designed fixture.There is no firm containment of lateral placement of the bulb, other than the bayonet bumps on the side of the ground case, there is a slot but no push in and turn set up customary with these bulbs. i am pretty sure that pushing in and turning is how i messed this up and caused the short.

If one of the bulbs burn out, i would caution anyone to take off both plastic light lenses, remove the left and right torx screws and drop the whole unit (just takes 2 min.). It is the only way to ascertain proper placement of these bulbs and will save you the cussin and spittin that you will do trying to get the bulb in otherwise.

Post by **BEJinFbk** » 13 Jul 2012, 09:39

Glad you finally found it.
It's always a good feeling...