speedo binacle problem

[AD Ent]

I once lost the left rear taillight, all bulbs were fine. but the wires going to the back of the cluster were fecked. Some were just holding, some were hanging together by a strand, in poor shape. Snipped them back, made a join and then some heatshrink. Lovely job, Taillight back on.,:thumb2 But why does my dash not work right? Back to the Rear Taillight, found another wire in not good shape, repaired it and dash back working again. Strange because there were no blown fuses.
Worth a check anyway. Looks like water gets in the wiring and corrodes. Poor design really.
You'll need a torch because you will have to follow back more than you think, and there aint no room either.
lots of knuckle scuffs.

 

[ste68blue]

Right guys a quick update...

Today i thought i would dig a little deeper into my electrical problem...I stripped the lower part of the drivers side dash so that i could get to the fuse box nice and easy, stripped off the centre console and gear stick gaiters so that i could get to the gear box and reverse switch.

Once i had done all of this i had a look at the wiring diagram and it shows a yellow wire coming out of the fuse box through the wiring loom to the reverse switch on the gear box then comes out as a red wire that then goes to the rear lights.

Please remember i dont claim to be an electrician....:augie

So i disconnected the plug off of the reverse switch and put my multi tester on the yellow wire and touched it to earth with my tester on continuity and it bleeped which i assume means that the yellow wire is making earth somewhere along the way, through the loom.

So i tried to inspect the loom all the way from the fuse box up the back of the dash, through the engine bay and down to the gearbox and i have to say i couldnt see any problems with it...

So i am now stumped and i have temporarily disconnected the plug into the reverse switch until i can have a brain wave....

Any ideas??

 

[firebobby]

Try running a separate wire from the feed to the switch and see if that cures it, if it does, just reroute a new wire

 

[ste68blue]

Hi thanks for the reply.

I did consider snipping the yellow wire coming out of the fuse box and running a new wire from there to the switch, but if my intelligence reads right the yellow wire must come out of the fuse box and then supply other things by splitting off to other items, ideally what i need to to i guess is find where it splits and then snip it from there and run a new wire, if that makes sense?

The problem i have found is that the wire disappears into a loom and then up the back of the dashboard....

 

[Lazy-Ferret]

According to the wiring diag, Fuse 12, which the yellow comes off of, does all sorts, including the rev lights, gauges and speed sensor, so best not snip it at the fuse end. Unfortunately, it does not say where the joins/splits are in the loom.

The thing is, if the wire is in situ, and only blows the fuse when you select reverse, the fault has to be either the switch, or the cable from the switch to the rear lights... or the actual lights of course, but can't be that actual wire to the switch, otherwise that would blow the fuse continually.

Just going to go back and have a re-read of your fault finding.

 

[Lazy-Ferret]

Reading what you have written, because of all the other things connected to the yellow wire your continuity meter has given you a false reading.

Try putting the yellow wire back onto the reversing light switch, but taking the red wire off. Select reverse and see if the fuse blows. If it does, the switch is faulty (unlikely), if if does not, then it one the red wire going to the back of the car, which is most likely, as this wire runs in lots of places it can get trapped and worn. To be honest, if it was me, unless I had made any recent mods that may have caused the short, and could be in danger of shorting more in the future, just run a new wire from the switch to the back of the car.

Before your do that though, if you have either a 13 pin, or grey 7 pin towing socket, I would definitely be blaming that, or the attachments of that socket to the cars wiring loom as the most likely place for the fault, in fact, even if it does not currently have a tow bar on it, I would be checking to see if one had been removed, and the wires cut off, as some garages think that cars having towbars on reduces the selling price and take them off to sell the car, often just chopping the cables off under the car.

 

[ste68blue]

Hi thanks for the reply, all help is much appreciated.

Yes i can understand what you mean about the yellow wire and the false reading...as it is supplying other things too...

When i had it all in bits i did do the same test with the red wire and the meter didnt beep...

It did originally have a tow bar on and i took it off last year some time but left the wiring and the plug in place and just tucked it up out of the way, do you think then that this may be a factor to consider?

cheers
stephen

 

[Lazy-Ferret]

The problem with a continuity tester, is it only makes a positive indication, when what you are putting it across has a low resistance, so the problem is, when it does not make a good connection, it will read that the wire is open circuit, even if the probe is on a bit of junk stopping the connection.

Maybe the red wire was shorting, and when you took the panels off to get to it, you stopped the short...

I am pretty sure though from what you say, it comes down to either the switch it's self, or the red wire connection going towards the back of the car

It did originally have a tow bar on and i took it off last year some time but left the wiring and the plug in place and just tucked it up out of the way, do you think then that this may be a factor to consider?

cheers
stephen

As long as it either had twin 7 pin sockets, or a 13pin, I would definitely start with the grey tow bar socket, in fact if I was a gambling man, I would place a bet on it being something to do with either the actual socket, or where it has been wired into the main loom. Probably got salt in the socket, and now it has corroded.

If it only had one 7 pin black socket, then this is probably not the cause.