melted wiring

Hi Guys,
I have recently smarted from having to stump up for a gearbox change in my 03 4.4 lpg converted RR. this week it let me down and it transpires that a load wiring has melted causing all sorts of electrical failures. Earlier in the day though i was in D and the box didn't seem to want to change up. I was doing 3000rpm doing 50mph, i put it into manual and still wouldn't change up. It may have been i was in 3 and wouldn't change to 4. This glitch righted itself after a few minutes and the box seemed to operate normally. Later on having stopped for a couple of hours i was in manual and there was smell i thought was from outside, but the smoke in the cabin made me change that view. There was no fire just smoke. I had the vehicle relayed to the indi LR specialist who did the box change, they have confirmed the melted wiring but is unsure of the cause, although they have suggested something to do with the LPG but i've not had any problems with this prior to the gearbox change. I wonder if the glitch that occured earlier was something to do with the failure. Basically a surge of power has caused the wiring failure and all the other electrical circuits have shorted. Any suggestions would be appreciated.

Thanks

Neil

A short has caused the loom to cook. Nothing to do with LPG. The engine is completely separate, electrically from the gearbox. You will either have to make up a new loom, splicing in existing plugs etc. with soldered and heat shrink covered joints or see if you can get one from a breakers etc. Follow the loom back and look fot signs of trapping and exposure to heat etc. Wiring looms use cable sizes well able to handle the imposed loads and don't just burn out without a definate reason,

Is it possible there could have been a power surge which caused the wiring to melt. The garage has said that the cabling had not been touching anything, so a fault somewhere caused the melt. Could the power surge have come from the gearbox bearing in mind the recent new box and glitch i explained before. I'm trying to understand if it is possible for a power surge to cause this melt or as i suspect the garage are protecting themselves by diagnosing a fault to another cause. Thanks

If there was a power surge then I would have thought-if it was current, that fuses would have blown and if it was voltage at an extremely high level, every gauge, ECU, bulb etc. would have fried. Hard to see how it affected just one circuit??????????????

lightu said:

Is it possible there could have been a power surge which caused the wiring to melt. The garage has said that the cabling had not been touching anything, so a fault somewhere caused the melt. Could the power surge have come from the gearbox bearing in mind the recent new box and glitch i explained before. I'm trying to understand if it is possible for a power surge to cause this melt or as i suspect the garage are protecting themselves by diagnosing a fault to another cause. Thanks

Click to expand...

Virtually every circuit on modern cars is protected by a fuse between it and the battery, so it would seem unlikely to be a "Power Surge" because as Irish Rover said the fuses would blow. The alternator is really the only source of a voltage surge which could occur if the regulator fails. In addition, battery's are very good at absorbing short duration voltage surges. My bet would be that the loom became trapped. The garage might be unwilling to admit to this as they would get the blame whether or not they caused the problem.

Someone mentioned to me that the wiring loom is attached to the gearbox somewhere and if you try to drop the gear box without disconnection of the bracket or something carrying the wires, things get pulled etc? This was on my Defender, is it the same on a rangie?

My money is on it either being damaged on removal, or more likely incorrect routing when refitted, power surge is plain rubbish.
Ask to see the extent of the damage-take photo's and tell them you may see what insurance company will do.
Do this for 2 reasons,
1) so we can see if it's been trapped
2)for your own record

My money is on it either being damaged on removal, or more likely incorrect routing when refitted, power surge is plain rubbish.
also
I'm wondering if an earth wasn't connected-several times I have seen wiring fried by missing earth. Try no earth on any vehicle and turn the key= melted throttle cables,wiring and in the case of a local vauxhall garage a blown ecu.

Ask to see the extent of the damage-take photo's and tell them you may see what insurance company will do.
Do this for 2 reasons,
1) so we can see if it's been trapped
2)for your own record