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Hey all, I have a 2007 v8 vantage coupe. I had it on a Ctek 7002 trickle charger and when I took it out this morning, nothing on the dash worked. Speedo and rpm is frozen. Lights, radio, AC all work… just the dash is dead. I googled it and it seemed like the roadster folks had this issue with their CRM but mine is a coupe. I located the cabin fuse and noted that fuse 46 was blown. I replaced it and it blew immediately. Any ideas?
FYI when it was on a trickle charger plugged in the trunk and we’ve had lightning storms/power surges so maybe that was the culprit?
Any help/input is appreciated
Update: Thanks to @hsm precision and the electrical schematics, I confirmed which things Fuse 46 controls. I went back at it this morning, put a new fuse, reconnected the battery and tested the functions. First thing to note, the fuse blew...however, whats odd is that all the items in green still works (master light, interior boot switch, center console/AC) but all the things circled in red did not. How is it possible that the green items still work with a blown fuse (I actually removed it)? My next step later this afternoon is to remove the instrument panel as I fear this is what's shorted as for some reason, the needles on the speedo and tach are not at zero.
Edwin
Last edited by PrecisionPorsch; Sep 12, 2021 at 08:32 AM.
Hi,
Fuse 46 goes to quite a few areas - I don't envy you having to dig through that
Here is a link to the workshop manual files I have - the electrical one has the full list of what is on that fuse on p56. (sheet 33).
It looks like F46 powers the interior light relay, so that should be easy to pull and isolate that at least.
As said above, I don't envy you. I would buy a box of whatever size fuze F46 is, as you will likely need them... A ohm meter will be your best friend, as it sounds like the fuze blows immediately. If I had this issue, I'd put the meter across the downstream (EG, fuzed side) of the fuse to ground and verify that it is shorted. Work your way around the easy items and remove and see if the impedance changes. Likely it won't.
Then start removing the modules that require effort to remove. At some point you will isolate the branch that is shorting. Your challenge then will be to discern if it is a module, OR, a power lead that has worn through and is making contact with the frame. Given this is a 2007 that can't be ruled out. When I rebuilt my 06 DB9, I spent quite a bit of time adding heat shrink and automotive loom tape to my harness as it was showing wear due to vibration and contact.
As said above, I don't envy you. I would buy a box of whatever size fuze F46 is, as you will likely need them... A ohm meter will be your best friend, as it sounds like the fuze blows immediately. If I had this issue, I'd put the meter across the downstream (EG, fuzed side) of the fuse to ground and verify that it is shorted. Work your way around the easy items and remove and see if the impedance changes. Likely it won't.
Then start removing the modules that require effort to remove. At some point you will isolate the branch that is shorting. Your challenge then will be to discern if it is a module, OR, a power lead that has worn through and is making contact with the frame. Given this is a 2007 that can't be ruled out. When I rebuilt my 06 DB9, I spent quite a bit of time adding heat shrink and automotive loom tape to my harness as it was showing wear due to vibration and contact.
As always, YMMV!
Larry
thank you Larry. Had trouble sleeping last night bc of this 😠. Quick/stupid question, when I, testing the impedance, is the battery connected or no?
Locate the power off switch behind the passenger seat. The one you push if leaving the car for an extended time. Unplug that module. Let me know if that helps.
Locate the power off switch behind the passenger seat. The one you push if leaving the car for an extended time. Unplug that module. Let me know if that helps.
Is there a diagram of where the module is? Also, I just updated the original post after more tinkering this morning. Thanks for your help
Glad I was able to help (a bit).
The fact that there is likely a short in the power may not be that bad a news - it's good info to help isolate the problem.
I'd start pulling fuses until you can figure out what circuit is back-feeding fuse 46, then see where those 2 could be shorted.
I think the battery switch is also good advise to isolate - in my 2007, it's in the trunk, right beside where you plug in the trickle charger so it may be in a different location depending on the model/age.
Matt
So another update: Took apart the dash (was surprisingly easy), removed the instrument panel and replaced the 46 fuse and reconnected the battery... viola... fuse 46 is good and not blown. However, there is no power to the glove box button so I still can't open it.
I think I've narrowed it down to either the glovebox switch, the instrument cluster or the wires between these three (instrument cluster, glove box and fuse box). Does anyone know if there's a way to manually open the glove box so I can unplug the switch back there? Also, if it is the instrument cluster, has anyone replaced it with a used one before (how does the mileage work) or is there an outfit that can repair it?
thanks Matt. Believe it or not, the panel holding the glovebox button just pulls out 😂 and I disconnected it. Unfortunately the fuse blew once I reconnected the instrument panel (with the glove box button disconnected) so I think it’s the panel. Now to research who can fix it or if I need to buy a new one
Before you buy a new instrument panel be aware that the short might not be actually IN the instrument panel. It could be somewhere else and the instrument panel is just a “pass through “
I would try and “borrow” a known good unit for testing purposes.
Looks like the little LCD panel might be to blame in this case. You might want to open up the cluster and see if you can tell what blew up
Yeah I think that's the next step. I'm by no means an electrician so I hope I'll see a clear burned mark somewhere
Originally Posted by embdenb
Before you buy a new instrument panel be aware that the short might not be actually IN the instrument panel. It could be somewhere else and the instrument panel is just a “pass through “
I would try and “borrow” a known good unit for testing purposes.
I would love to but unfortunately, I don't think anyone would be willing to lend me theirs (and I don't blame them haha)
Originally Posted by MRCW
If you think it's the panel, I'd do a continuity (ohm) test on the plug and harness to the panel first...
@MRCW , that's a great idea. Will try that. Thanks
Sorry for the resurrection of an old tread however really could use some help. Edwin did you ever find out what caused the short. My Cluster went dead last night. So bummed. Fuse 46 blows when I replace it.
Update: I lucked out.
First I unhooked the glovebox release, blew fuse
Unhooked the battery switch-off button, put in new fuse and no blow. I dodged a bullet with it being not being the gauge cluster.
I just have to now figure out the short in the battery switch-off circuit
