Fueled by fond memories of my LWB SIII, I recently bought a SWB SIII from a leading specialist in Classic Land Rover. On collection I noticed that the temperature gauge didn't work which wasn't clever because it had an elective switch to activate the Kenlowe fan. Bonnet melting not being a good pointer for switching the Kenlowe on... During examination, a company's employee shorted the electrics resulting in lots of fumes coming out of the dashboard. An external car-electrician had to work on (repair) the car. Surprisingly the company emailed "he did not have to offer either of these options to you, but as a goodwill gesture he offered to cover the several hundred pounds of free delivery (put into perspective, the company driver passed us on his way Plymouth!). On top of that we have completely replaced the front wiring harness professionally at a cost of over £1000. We also did not have to do this, but to please you it was fully replaced with extra fuses on your request - somewhat of a free upgrade." This was after them frying the wiring... Classic Land Rover company subsequently delivered the car as 'repaired'.

Problem is that the top fuse in the fuse box keeps on blowing. It renders the car illegal to drive because it disables brake lights and indicators. I drove the car today to diagnose, progressively loading Amps to the system... so with lights on main beam things were OK, adding indicators seemed OK, applying brakes OK, finally I switched on the Kenlowe and for some 30 minutes everything seemed to be OK, then out of the blue the top fuse in the fuse box melted. Random electrical errors are any electrician's nightmare, I understand that.

Still, it renders the car unfit for purpose, it becomes illegal to drive and unreliable. For how many fuses do you need to carry to make a journey from Harborough to Newmarket?!? My question to the forum is how to go about finding what causes this shorting. The very uncooperative Classic Land Rover specialist might drive the car for less than 30 minutes and never find the problem, erroneously causing them to think they're right. But they're not, there is an innate problem with electrics.

My LWB SIII was ultra reliable and a 1948 car I have is ultra reliable. So the Classic Land Rover people saying "We do not guarantee these items under our warranty as they are very prone to sudden failure" and "a 40 year old vehicle will always be unpredictable by its very nature" is illogical. It ignores the obvious which is that Land Rovers achieved their iconic status because they were utterly capable and dependable vehicles.

Please can you advise how best to diagnose and sort this electronic problem.
Many thanks in advance!

All I did was disconnect everything and re connect one at a time until something started cooking. Eventually I came out on top. Just a case of trial and error for me.
Took ruddy ages though.

Series 3 wiring is fairly straight forward if you have a wiring diagram. It's not too hard to trace the wires around the individual circuits. . If it was me, I'd start looking at the indicator switch.

Col

Colthebrummie said:

Series 3 wiring is fairly straight forward if you have a wiring diagram. It's not too hard to trace the wires around the individual circuits. . If it was me, I'd start looking at the indicator switch.

Col

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I'd make sure the fan has a relay and fuse independent of the original loom they draw huge amps on startup

completely agree with sausage, get the fan off the landy fuse board.

electric motors are basically a dead short circuit when you ask them to accelerate from stand still, so you get a huge spike in current which rapidly falls off. i think this huge spike is probably overloading (although the glass fuses are huge arent they, 17amp or something) but anyway, advice is still the same.

on mine there was a 3rd fuse under the steering column which had nothing connected to the output (but had permanent battery feed to one side) not saying to use that, but its an avenue.

relaying it direct to battery might also be worth it, i know those knenlowe switches are usually full load, but relay would take the battering

is there a reason you can use a fixed fan on the water pump as it should be ?

DarrenHS3 said:

completely agree with sausage, get the fan off the landy fuse board.

on mine there was a 3rd fuse under the steering column which had nothing connected to the output (but had permanent battery feed to one side) not saying to use that, but its an avenue.
Same on mine, there wasn't a fuse in the third slot to start with...

is there a reason you can use a fixed fan on the water pump as it should be ?

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Same on the SWB SIII I bought, the third slot was left empty... My LWB SIII had everything as standard, it worked flawlessly. This SWB SIII came with a Kenlowe fitted and standard fan removed, when I queried this the Specialists in Classic Land Rover® said it was the better option. I fully understand the drawing a Kenlowe makes on the system on startup, what I don't understand is why it worked fine as I switched it on driving at 50mph and it blows when I slow down to 10mph in a village. Other than having to buy the parts, there is no reason at all why I cannot use the fan on the water pump as per original design!

Colthebrummie said:

Series 3 wiring is fairly straight forward if you have a wiring diagram. It's not too hard to trace the wires around the individual circuits. . If it was me, I'd start looking at the indicator switch.

Col

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I have a wiring diagram in the official Land Rover SERIES III booklet is this the one you refer to or are the better diagrams on offer? Challenge is that much of this SWB SIII's wiring does not follow the Land Rover colour scheme... If it was the indicator switch would it follow that with all lights on and Kenlowe fanning, I would indicate left or right and this would overload the fuse? Last time it blew I drove straight on i.e. no indicators switch use...

cant really answer that, load on the fan couldve been getting an assist from high pressure coming in through the radiator. could be engine rpm (and thus voltage) related.

no point having an inquest really, it doesnt sound like there is an actual fault, rather just an deficiency someone hasnt factored in.

if you are worried about a short circuit i read a trick about replacing the fuse with a 12v test lamp (would need crock clips and a holder) obviously with nothing switched on, or no fault, the lamp should not be lit