General glow plug fuse blowing

[hughes_fr]

Hello All,

My Brava 1.9TD100 refuses to start! The 60A glow plug fuse keeps blowing. Does anyone know if the injector/pump is also connected to this fuse? I have tried using 'easy start' spray in the air intake but it seems as if diesel is not getting to the cylinders.

I am thinking that I may disconnect the output from the relay (to the plugs) and then trying again with a new fuse. If there is a short in the plugs/leads then hopefully it would not blow and the motor could start and I could get to the garage.

If anyone has any experience of this, advice would be appreciated,

Thanks

Darren [this is my first problem with the car in 80k miles!]

 

[bridges]

My knowledge on diesels is a little limited, however.

Do the glow plugs get chance to heat at all? 20 seconds of duration will be a minimum requirement otherwise the car will never start until there is enough heat in the combustion chamber to cause combustion once the diesel/air is compressed.

This issue will certainly need addressing first and if the fuse is blowing it suggests a short in the glow plug circuit. I would check that the positive wire feeding the plugs has not earthed out due to a split in the wire or through a damaged plug.

Pump wise its a mechanical pump but is possible the stop solenoid is failing to open. I think you should hear a click when the ignition is primed at the pump as the solonoid opens.

Hope this helps

 

[hughes_fr]

Hi, Thanks for the reply.

No, the glow plug light does not come on at all. When I try a new fuse, there is a 'key' symbol on the dash which lights up as normal along with the battery one, then after a few seconds the fuse pops and when I try again the key light is off. The engine turns perfectly well but does not fire.

I bet you are right about the short-circuit in the feed wire but I was hoping to avoid having to get to the wire/plugs on my own as it seems I would have to remove loads of stuff to get to them. I sometimes wish my hands were smaller!

Thanks again.

 

[bridges]

Unfortunately the engine will not start at all unless the glow plugs heat up. I believe that this is definately the problem.

Undo the live wire from the glow plugs. It should attach to the 1st plug via an 8 or 6mm nut, undo just this one.
Then there should be linked wires from plug to plug transfering the current. ignore these for now. replace fuse. Does it still blow?

If not then the problem is at the plugs/ or is a problem only occuring under load.

If it does then its more likely an issue between the relay and ignition.

If it does then it is possible to bypass just this once and heat the plugs by hot wiring direct from the battery, use caution. ideally a two man job though as someone will need to turn the key.

 

[bridges]

There are some diesel experts on this forum so it might be wise to let them post. This might be a common fault that is easily remedied.

 

[jug]

Unfortunately the engine will not start at all unless the glow plugs heat up.

dont be so sure, they usually do start without glow plugs unless it is very very cold, it just takes a couple of mins cranking.

i agree a short to earth from the glow plug feed seems most likely.

 

[bridges]

dont be so sure, they usually do start without glow plugs unless it is very very cold, it just takes a couple of mins cranking.

Am glad you said that. It Makes sense as its the compression that heats/combusts the diesel. However even after a journey and with the car up to temp my 100td will not start without the plugs. yet I can heat them very briefly and it starts on the button. Strange.

 

[hughes_fr]

Thanks for the replies.

Working on your 'short' idea, I took a look over the weekend. To be honest the wires are very difficult to get access to on the TD100. It looked like one of the cables was twisted quite tightly around a bump on the engine. The only way to lift it off was to use a bent metal hook. When I had the cable off the engine I put in a new fuse and it started (although the glow plug light did not come on). I guess the plastic sheath has worn through.

I have taken it to the garage so they can take a look because it looks like half the engine needs to come out to get the wires off!

Thanks again for the advice

Darren

 

[bridges]

No problem. it might have also blown the indication bulb in the dash, possibly.

 

[stylers]

the 60A glow plug fuse also feeds the ECU and fuel filter heater. but if its blowing the main fuse, this means either a shorting glow plug or glow plug feed wire from relay, or a short in the feed to the other circuits. check the loom to the glow plug relay and plugs, this is most likely the cause. the TD100 will not start without heating, for some reason even if the engine is warm, you have to give it a few seconds.