Yo! Long story short, I have an electrical issue with my hippo, the vehicle is an 02 commercial, retrofitted by the local land rover dealer where it was ordered from, with all the optional/accessory driving/fog & spotlights. The car broke down while I was away from home and my wife was using it, apparently it drove sweet as a nut to her destination, when she went back to it to go home, it showed no signs of electrical power whatsoever. One of our friends tried jumpstarting the hippo for her, to no avail, so my wife made arrangements for a local garage to recover and investigate it. First thing the local garage did was check fuses, and found the little mini fusebox above the fuel filter, I've highlighted in the pictures, as having melted fuses in it, so they removed the battery terminals and walked away from it saying they thought it could be a can of worms and didn't want to get involed.

So, now I'm back home, and I'm hoping to get on the case with a multimeter and see whats what, starting tomorrow, but I was wondering if anyone knew what this mini fusebox in the engine bay is for? I have tried finding it on rave and microcat, as I was going to order a replacement box, as if its melted a fuse its probably scorched the fuse holder? However I had no joy and couldn't find it in either system. I've also had a look on google at hippo td4 engine pictures, and some have these additional boxes, others don't? This brings me back to the lights? I wonder if the fuses in that little box are for the spot/fog lamps?


What I am thinking is I need to identify what that box is for, which of the 3x 30 amp fuses in it melted, what caused it to melt, repair or isolate that system to make the vehicle electrically safe again. Then when I'm happy I'm not going to cause an electrical fire, reconnect the battery and try to get it starting again. My worry is that the initial breakdown may have been something simple like a battery terminal clamp had rattled off and the aforementioned friend might have reversed the jumpleads, causing the fuse(s) to melt and lordy only knows what other damage. Best case is that the little fuse box is for the extra lights, and I can safely isolate that circuit, get the vehicle running again, and come back to fixing the lights after that.

I managed to get across to where the hippo is stored just now, had a rummage and found the owners handbook, this has a page explaining that the supplemantary fusebox can be for either the heated front screen if fitted with 2x 30 & 1x 7.5 amp fuses, or be for the PTC if, like mine is, it is fitted with 3x30 amp fuses. A bit of googling later and it turns out PTC stands for Positive Temperature Coefficient, and refers to an electric auxiliary heater element incorporated into the heater assembly located just below the heater matrix. After jumping back into RAVE, I now know that the PTC is operated by a couple of relays the first of which is energised by the fuel pump relay, other controls are heater thermostat position, fan blower switch position. In essence, only when the fuel pump is energised, AND the ignition switch is in position 2, AND the thermostat is past 1 o'clock, will it energise the feeds to the three heater elements in the PTC heater, one on each of the 3x 30A fuses.

I'll try and put together all the information I've referenced together into one PDF for future use by other forum users, after I get our hippo running again.

Pulling the PTC fuses won't stop the engine from running, or the heater from working. I also don't think it's responsible for your dead battery, although it's possible the relay has stuck on. Pull the relay and fuses, then charge the battery and measure the current drain on the battery.

I dont think the PTC is the culprit, but I had to figure out what those melted fuses were connected to before I faffed about with other electrical fault finding, as given the garage the landy went to described it as a melted fuse box on the phone, which I had pictured as being the main engine fuse box melted, and three thirty amp fuses melted, that must have been a hell of a lot of current? Lucky it didnt start an electrical fire, so I'm treading lightly.

My gut was telling me the melted fuses are a valid thing to investigate and fix but a red herring regarding the breakdown. But I had to be sure they weren't critical systems like say Fuel Pump, Alternator Excitation etc. The actual prime suspects for what was up with it when it broke down was a battery clamp came loose, and or it was a loose wire on the starter where the main live from comes from battery to starter and is met with another eyelet ended cable going to the main fusebox both eyelets bolt onto the main power to starter solenoid.

But now I know what system those fuses were part of, I've been able to figure out how to isolate those three melted fuses and the PTC heater they feed, leaving me the simple matter of getting it running again. And I think we are agreed that the rest of repair process is just going to be straight forward auto-sparky-ing, most likely leading to something pretty simple. And I wouldn't be surprised if I have the vehicle running again in less time than its taken me to figure out what those three fuses in the supplementary box are/were for.

Fuses would normally break open if the internal fuse wire over heats due to the current flow through it being higher than the rating of the fuse. Were the over heated fuses the correct rating?

Sorry - I meant to update this thread on Friday night to let y'all know that I've got the freelander running again, it was as we discussed simple autosparkying and those melted fuses were indeed a red herring. That being said I've I've still to fully fault find the melted fuses for the PTC, I do however have a theory on that, which I'll come back to.

How I got it back to life was the first thing I noticed was that the positive battery clamp was loose, so I split it down and filed a larger gap in the split so it could bite tighter, then put the power back on to car, went to start it, ring around ignition barrel was illuminated, turned key, dash lit up, tried to crank - complete black out. Went back to battery with multimeter, 12.7V, followed feed into fusebox, checked feed against battery neutral, 12.7V, went to first fuse in fusebox, 4.6V. Took battery live off, removed live lead from fuse box, and it was minging, verdi gris galore. So I got some super fine emery cloth followed by scotchbrite, cleaned it up followed by scotchbrite for the fuseable link. Put the power back on, 12.6V at all fuses, back to the drivers door, key in, all the usual lights on dash, cranked her starter and she started immediately. Left the beemer with that garage as its due an MOT, took the freelander home and have been using it since and its 100% reliable. Hopefully cleaning up the dirty contacts has cured it.

SO... about those melted fuses for the PTC heater... A couple of years ago the freelander was on loan to someone, when they gave me the vehicle back they admitted the heater blower hadn't been working for quite sometime. Quick bit of fault finding and the terminals onto the motor itself were loosed, due to a dodgy plug, so did something with it. Might have been new spades crimped on to the wiring tails, or a plug cut from a scrap freelander and spliced, might have soldered the tails ordid some plastic surgery to the plug? Cannae mind...

However, the person who had the use of the vehicle had been running about with the fan switched on, temperature up, etc... essentially everything was lined up to put power to the PTC heater, and it probably was getting power, but since the blower motor wasn't getting power, it wasn't blowing cool air across it meaning the elements would be a lot hotter than intended, so the resistance would be through the roof, causing (voltage to rise?) thus melting the fuses.

I'm going to do a few more bits on it later this week, including:

• an upgraded head unit and a new aerial to get a radio signal, I suspect the current one is corroded around its ground point
• try and identify which wheel bearing(s) is / are now growling - might have been growling for ages but been masked by the tyre noise from my 225/75/16 Kumho KL71's which I've taken off it for now and fitted its other wheels with 235/70/16 BFG all terrains
• Wheel alignment, its really needs doing as it is miles out, and has been since I put the lift kit on it and new track rod assemblies in the winter. I will need to set up my proper alignment machine and spend some time on it, not just a quick toe adjustment. Also don't know if the back toe arms adjusters will ever move again, but I wont fight them too hard, if they don't want to play ball with a bit of heat and brutality I'll replace them
• check/top up the diff and IRD oils
• touch in any missed bits of waxoyl
• And after all that, pick up the PTC heater investigation. I'm rapidly leaning towards the idea of replacing that supplementary fusebox with one from a breakers yard.