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Ferret ignition troubles


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Hello guys,

Slightly odd problem with the Ferret in that it's developed an intermittent ignition problem. When turning the ignition on rarely it lights up as per usual, mostly I get no lights at all and when swinging the starter catch I get no starter, and the lights dimly glow, along with the fuel gauge dancing around. Even when the lights do illuminate it's hit and miss as to whether the starter will turn the engine over.

My battery voltages are fine, I've checked them and when it does illuminate and turn over it starts and continues to run no trouble at all. I've had every connection out of the round rubber block and cleaned with some fine emery and electrical cleaner. To me it sounds like an earth issue?

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Lewis,

 

Have you checked for corrosion on the terminals in the 2 donuts of wires? I had some pretty corroded ones, but the inside of the main switch box was my main culprit. I ended up replacing most of the wires and found a rebuild kit to replace the inside of the switch box.

 

Chris

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Hello Chris, hope you're well.

Yep I had the LH one to pieces by the ignition panel and cleaned it up. Indicators and hazards have now stopped working whereas they were fine before so a shoddy connection there now I think, my fault. I'll have a look at the RH one tomorrow.

Presumably there is one common earth point for all the dash electrics?

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Is your Switchboard No.1 still a Mk 1 or has it been upgraded to Mk 6?

 

The Mk 1 switch contacts are relatively crude & the brass contacts erode back making switching unreliable & erratic. The switching on the Mk 6 is of quite a different design & much more robust for the current it carries.

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Hi lewis

 

I had a similar issue on my ferret when I got it. It started to cut out on the road. It turned out to be connection issues inside the switch panel itself. Primarily the Ignition switch. I removed the switch panel and stripped it down. It was caused by some old electrical contact grease which had degraded causing continunuity issues, especially on the ignition switch. Cleaned up the internals in the box and it's been fine since. I remember it was a total git to get out and refit, on hands and knees perched on the drivers seat. I should have removed the seat in hindsight and maybe laid flat on the hull floor.

 

Good luck

 

Matt

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An earth problem on the instrument panel will have no effect on the starter as that has its own earth. The switchboard starter switch just has to supply 24+

 

As the panel lights & fuel gauge are dim or intermittent it suggests that they are not receiving 24+ which suggests to me there is a fault in the 10A circuit breaker that is in the distribution box.

 

The thing to do is measure the volts at R & verify it is 24+ then also this is the same on INS.

 

INS is what come out of the circuit breaker. It must be measured under load with the ignition & starter on. At rest there may be some voltage coming through but due to grotty or open contacts the voltage can still pass through the winding that triggers the circuit breaker. But the voltage cannot deliver much current due to the resistance & lights will be dim.

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Thanks for the replies chaps, it is indeed a Mk6 Clive. I have the switch panel apart at the moment, it is a complete sod to take apart in situ! I can't say I'm looking forward to putting it back together. It was a little dirty in places but nothing that I'd consider to be an obvious cause so I will follow that up.

20160503_203655_zpsdh1bytul.jpg

A number of the pins were looking rather crusty

 

IMG-20160504-WA0012_zpsf7310ou5.jpeg

As you can see the way it's come apart is effectively backwards to how was intended, never mind!

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Just make sure you don't have one of these jokers in there!

 

DSCF8363.jpg

 

These are all 12A plugs. The lower double female is 12A, but the upper double female is a 30A one. It holds the plugs in by the rubber lips but the electrical contact is unreliable.

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Hello chaps,

I've put the dash back together having cleaned up the contacts but still no joy. Upon pulling the starter switch down all that happens is the fuel gauge needle jumps up. Rather confused. I have to confess electrics aren't my forte, I've checked for 24v at ignition which I have one side, then the other when switched over. Will try and get a photo to illustrate where I'm getting power to.

Edited by Lewis Garner
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To me it points to a problem in the 10A circuit breaker

 

I assume your 24v is at IGN+ then with the ignition switched on you also get 24v at R?

 

R is the ignition switched supply to the 10A circuit breaker.

 

If you are only getting 12.2v on INS, as this is the supply out of the 10A circuit breaker the fault looks to be there.

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Now when I do get dash lights with ignition on which is very rare and intermittent, I get power to these points.

2016-05-07%2018.41.29_zps1qssf8et.jpg

 

As soon as the starter switch is actuated the lights go out, nothing happens and I lose power at various points.

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I'm sorry I can't relate to those connections at all.

 

It is a few years since I have been inside one & that was a Mk 1 which is wired & constructed rather differently to the Mk 6.

 

I can only visualise things if you can relate readings to the sleeve identity of each wire. At this stage the most fundamental thing to establish is that there is 24v from:

 

IGN+ (supply to ignition switch)

 

R (with ignition on that feeds into 10A circuit breaker)

 

INS (with ignition on that is the supply from the 10A circuit breaker to the instrument panel)

 

Unless you can get 24v at those key points, there is nothing to be gained at this stage taking readings within the switch itself I'm afraid.

 

Would you like a scan of just the starter & ignition circuit without all the other wiring?

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Hello Clive, thanks for your reply. Do you have a location for the 10A circuit breaker? Presumably the distribution box is the square box to the rear left of the fighting compartment located next to the charging socket?

 

Both circuit breakers are in the box that has the inter-vehicle starting socket. But don't pull it apart until you have confirmed whether your are getting 24v at R & INS.

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Ok well if you unscrew one bulb the 7-8v will increase a bit as it is having to flow through the resistance of the winding of the circuit breaker & the other light will brighten up a little.

 

The resistance of the CB winding will be in the range of 165-191 ohms. You could verify this with the power off & pull the leads INS & R to see if you get this reading. It should really be virtually zero ohms but if it not zero but below 165 ohms then the contacts of circuit breaker are corroded, arced or grotified. It should be watertight in there but doesn't always seem like that once you look inside.

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Clive, I owe you a great many pints if we ever have the pleasure of meeting again. I was somewhat desperate to get the vehicle back in the workshop this evening so with your having led me to the source I wondered if a curious tap with a spanner on the distribution box would have any result. It gave me some lights and hey presto, she sparked into life. I will be having a look inside tomorrow. Thanks very much for that, your knowledge is invaluable.

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Lewis that is satisfying pinning the problem down, glad to have helped guide you through it.

 

Unlike funny noises from engines, which certainly mystify me, I find electrical problems can follow a more logical diagnosis. Sitting with a circuit diagram does help focus one's mind on the area of concern.

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Clive, I, and I'm sure many other poeple would like to thank you for your time in helping Lewis because you are also helping others to keep their machines running. I have followed this post with interest and find your understanding of this subject amasing. Top man :).

 

Jim

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