Help! 451 Blown Fuse #12, short circuit

[denisjolicoeur]

Please help...

I have a 2008 451 with about 105,000 kms, now off of warranty..

Today I suddenly lost my instrument cluster, strip-panel switches (heated seats & sometimes door locks, & the rear hatch unlock switch), signal indicators.

More specifically, my speedo and tach are stuck at 30 kph & 2000 rpms respectfully, and the lights & leds beneath the speedo are all blank. (I don't have a fuel gauge, dummy lights, indicators, outside temp guage, etc...)

The rear turn signal lights work (with a fast flash) but the side indicators and front signal lights don't work...

I checked all of the fuses and #12 was blown... Tried replacing it and unfortunately every fuse I try immediately blows.. There's a short circuit there!

My wife's mechanic had a quick look and is also unsure on how to proceed.. He tested that fuse #12 slot and there's definately a "dead short" (even with everything turned off, tons of current)

Anyone see this before? Where would the short likely be?

[Duckhunter]

you can try and isolate the shorted circuit by disconnecting areas. Looks like indicators, ODB, Rear Fog?,Transmission. You mention heated seats, this would be a good current draw and cold easily short. I would start there. Not sure of the transmission but should not draw much except servo for gear change. Am not sure if that fuse is for that or just the low power electronics.

[Bum-bling-B]

Here goes......

My uncle had a Volvo in his repair shop with a similar problem. He had all of his mechanics check it over and over again with no luck and the car had numerous things replaced before he let me know about it and asked if I would like to take a stab at it.

From what you have said I would guess to check the turn signal bulbs - ALL OF THEM. Look at the contacts, better yet spend a couple bucks and replace them. Look at the socket where the bulbs came out too. Most likely it is a bulb IMO. While I could be wrong, it is a place to start since that would be a good place where you are getting the feedback causing the short.

I've blown Fuse 12 before but for a completely different reason and once again, most every problem I've had with my car....I did myself. Do you happen to run a Scangauge? Has the car thrown any codes?

[Duckhunter]

Noticed heated seats on own fuse and agree with all signal bulbs, just remove them all and try fuse again but should not be on unless lights on.

[Bum-bling-B]

I just re-read what I wrote and it isn't too clear. The Volvo I solved the similar problem on had the problem in a bulb. The contacts were fused together causing a short. I do agree you would have to cause that short by causing the lights to light. The bulbs are only a start since IMO they are the most fragile part where the short could have started.

[jetfuel]

...remove all turn signal bulbs...check draw..
...remove/unplug switches strip..check draw..
...if still drawing hard..you're only left with the onboard diagnostic plug or transmission control unit...
..as BBB said look at the light plugs closely...use a big bright light to aid in the inspection of the plugs/sockets..
jetfuel...good luck

[Duckhunter]

If you have been in lots of water lately it might be water in an exterior plug or elecrical connector.

[denisjolicoeur]

Thanks for all the feedback... I'm going to try the signal bulbs this evening (and keeping my fingers crossed)..

I'm picking up:
2 - 7528 (for the rear),
2 - 2357A (for the front)

and ??? What bulbs are needed for the side turn signal lamps? (I know my manual says wy5w but the manual is wrong on the others)

[Bum-bling-B]

Originally Posted by denisjolicoeur

Thanks for all the feedback... I'm going to try the signal bulbs this evening (and keeping my fingers crossed)..

I'm picking up:
2 - 7528 (for the rear),
2 - 2357A (for the front)

and ??? What bulbs are needed for the side turn signal lamps? (I know my manual says wy5w but the manual is wrong on the others)

I wouldn't worry about the side markers, never seen one of those direct plug in style wear like I have seen the twist in dual filament bulbs contacts wear. Good luck, it least it is a starting point and as Duckhunter and jet said, you can first get away with removing the bulbs and trying to replace the fuse with the bulbs out. Easier yet, just unplug the lights.

[denisjolicoeur]

Well... had time to try a few things this afternoon..

Removed all the signal bulbs (including the side-markers) and tried the fuse.. fuse blows..
Disconnected the switch strip.. fuse blows..