Ser II Lightweight 'shorted out' !! shoot me

[mrdoiron]

title should say Ser III (Lightweight)

ok, so had pretty much everything working......,

and then took off the license plate light to reseal, and while repositioning I managed to short out the hot wire to the frame, and got a good spark... then noticed smoldering from the engine bay - seems the wire fried all the through - but need to check what all it managed to fry, as the head lights will now shut off now - even with the key out, as they were in the on position I believe when the short occurred.

Very depressing... as I didn't notice the headlights at first, but did start the engine to ensure nothing else was worse - it started ok at the time. So I carried on for 30m cleaning up and tracing where the wire seemed to melt through etc. I then noticed the lights on, and thought odd, as I was pretty sure I removed the keys, and sure enough, they were out - but the lights stayed on.

To make matters worse, the truck will now not turn over... not sure what's happening as it did start immediately following the short...

Any ideas where I should start ?? It is a 24V, which I've disconnected dfor now...

shoot me.

[greenmeanie]

You have just discovered the drawback to an OEM LR harness - there are not enough fuses so your wire became one. At some point you'll find the wire bundle has melted into one homogenous lump of melted insulation and copper so you various circuits are now cross feeding. My guess is to look behind the dash as that is where most of the harness converges.

If you're lucky you can get away with replacing part of the harness. If you are unlucky you arenow in the market for a complete rewire. Either way install more fuses in your new harness.

[mrdoiron]

I opened up the light switch panel, and saw a few wires melted together. separated everything obvious.. and saw a possible source contributing to the problem, in a small piece of tape across a break in the wire cover of the wire to the rear plate light.. it was fused at a couple spots to other wires in a couple spots. One section in the engine bay had similar fused wires, so separated those also and re-taped.

I then started up, and yes, I had ignition...! My excitement was short lived however following two subsequent things :
1. I noticed that while the engine was running, the headlights would not come on (recall they were on while the truck was shut off prior).
2. I taped up everything a little more securly and closed up the dash...

THEN - tried to start up again, and not turn over... just a small tick tick, not engine turn. Is it possible the starter solenoid could be intermittently working ? It doesn't appear to have been fried, and it did start twice since the short...

So I shut off, took out key,.... and the headlights are back on !! Shoot me again.

I think I'll need someone with more electrical debug skills (and patience than I), although I'd love some advice...

mike

[roverlandpark]

Since your Lightweight is ex-MoD, maybe it's a short in the 6-way light switch? These are prone to failure. You may get some advice via http://www.lightweightlandroverclub.org. Just a thought...

[mrdoiron]

thanks, put out an APB to anywhere I could find - just add there too - thanks

[teechizpet]

Try the EMLRA electrical section. They are extremely knowlegable as well as helpful.

[amcordo]

Beware that the tick ticking could also be a now-damaged battery(s) that is/are unable to put out enough power to turn your car over. Had that happen once just from a simple tiny short.



While you're fixing this use an old crappy battery if possible to save your nice one.

[mrdoiron]

Beware that the tick ticking could also be a now-damaged battery(s) that is/are unable to put out enough power to turn your car over. Had that happen once just from a simple tiny short.



While you're fixing this use an old crappy battery if possible to save your nice one.

Thanks,
You know I wondered that, and checked with voltmeter, and am getting 24V across the 2 connected, and 12 on each individually. I am baffled on how it started up (but headlights were not on - then it wouldn't start, and headlights stayed on after I took the key out tell me something crossed that shouldn't have. Since I disconnected the battery and reconnected, the lights have not come on (headlights that is, others are all working fine.)

Per another suggestion I am going to order a wore harness I think, as well as new starter solenoid, and of course the culprit rear plate light assy !


mike

[greenmeanie]

WHen looking at harnesses consider how you will add fusing for EACH circuit. The OEM harness just is not that good. On MOD trucks the number plate light lead is notorious for shorting, taking out the 6-way and then melting the whole lot to slag. No point is spending hard earned cash only for a repeat performance.

If you really want an OEM harness I would either add in line fuses which are ugly but allow you to keep closest to the original design or add an aftermarket fuse block.

Converting your headlights to commonly described relays removes the higher currents from the 6-way after which they give no problem. LR liked to run full circuit power through the dash switches which both reduces their life, adds resistance to the circuit and increases the potential for meltdowns where the harness bundles behind the dash. I prefer to convert any high load circuits to relays to remove this problem. Just document your modified wiring when you do this as it will save many headaches in the future.

[mrdoiron]

WHen looking at harnesses consider how you will add fusing for EACH circuit. The OEM harness just is not that good. On MOD trucks the number plate light lead is notorious for shorting, taking out the 6-way and then melting the whole lot to slag. No point is spending hard earned cash only for a repeat performance.

If you really want an OEM harness I would either add in line fuses which are ugly but allow you to keep closest to the original design or add an aftermarket fuse block.

Converting your headlights to commonly described relays removes the higher currents from the 6-way after which they give no problem. LR liked to run full circuit power through the dash switches which both reduces their life, adds resistance to the circuit and increases the potential for meltdowns where the harness bundles behind the dash. I prefer to convert any high load circuits to relays to remove this problem. Just document your modified wiring when you do this as it will save many headaches in the future.

Fuses strategically placed make a lot of sense, surprised that MOD vehicle didn't have such a defensive measure... apparently I fried the rear loom from the back forward to the bulkhead, and the melted the multi-block connector were the front and rear looms join to the bulkhead loom, this has then melted the control wire to the 6 way switch-----wonderful. ..likely the metal relays have also meltdown. To repair this (with time and patience) need to trace every melted wire and replace it , but will likely get a new harness loom and let a professional do it (my patience there not a spiritual gift).

Jac04 - had you put in a new harness on yours ? Now sure if you have a 24V or not, but any tips appreciated...

Also still not sure if relay's or solenoid is shot, I cant get it to turn, just a tick tick when key is turned...

I was so close, replacing that rear plate light was the final piece after paint... shoot me again...

[jac04]

On MOD trucks the number plate light lead is notorious for shorting, taking out the 6-way and then melting the whole lot to slag.

Any idea of why/where it shorts? I put a new plate light on mine and the wiring was very simple with no obvious potential problem spots. If there is something to correct, I would like to take care of it now.

Mike- Mine is a 12V. I re-used the harness because it was in excellent condition. I quickly realized the headlight circuit wasn't the greatest, and converted the headlights to run off relays. Sorry I can't be of more help.

[mrdoiron]

Any idea of why/where it shorts? I put a new plate light on mine and the wiring was very simple with no obvious potential problem spots. If there is something to correct, I would like to take care of it now.

Mike- Mine is a 12V. I re-used the harness because it was in excellent condition. I quickly realized the headlight circuit wasn't the greatest, and converted the headlights to run off relays. Sorry I can't be of more help.

When the light assy was removed for painting, the center "U" piece rivoted that the bulbs press against broke off. In an attempt to reattach, I touched the hot wire to the frame...my bad for sure. watch however if ever replacing a bulb etc...as I would never have guess that a short out there could do so much damage...

[jac04]

watch however if ever replacing a bulb etc...as I would never have guess that a short out there could do so much damage...

For sure. Your experience has definitely made me more cautious.

One other thing that I have on my vehicle is a master cutoff switch that isolates the battery from the vehicle. Unless I'm driving, I always have the master shut off. Maybe overkill, but I sleep better at night because of it.

[NelsAnderson]

One other thing that I have on my vehicle is a master cutoff switch that isolates the battery from the vehicle. Unless I'm driving, I always have the master shut off. Maybe overkill, but I sleep better at night because of it.

I've thought about doing that...even bought the switch. But haven't figured where I want to put it. Can you show where and how you mounted it?

[jac04]

^^I mounted it on the top of the passenger side footwell. I'll try to remember to snap a picture tonight.