[Engine] Heat damaged loom

[Soarer]

Hi All

I am looking for some advice please. Some of you may remember I posted at the start of the COVID-19  Lockdown about my Partner not starting (drove great on Sunday but wouldn’t start on Monday, disconnect and then reconnect battery and it would fire up for a second and then stop , tried new key in case it was immobiliser) which some of you though sounded like a Crank Sensor failure. Because of the lockdown the garage couldn’t do anything. 

So they started work on it yesterday with the aim to replace the Crank Sensor; however, they sent me pictures of section of a wiring loom that had suffered some heat damage, they think it is from the section of loom that supplies power to the Glow Plugs in the Coolant System (didn’t even know the coolant system had glow plugs), does this sound correct, is it a common issue, can you buy replacement section of loom, etc. 

Any advice would be greatly appreciated 

Kind Regards 

Tom

[Sol]

That will be the auxiliary heating mate. It is a kind of glow plug setup. It's meant to help heat the cabin when outside temps are low and coolant is cold, due to the high thermal efficiency of a modern diesel. If you watch a modern HDi / TDi they will cool by them selves at idle and only generate heat when working against a load. This system produces cabin heat in that case when required by the heating controls.

Not sure about buying a part-harness...

[Soarer]

That will be the auxiliary heating mate. It is a kind of glow plug setup. It's meant to help heat the cabin when outside temps are low and coolant is cold, due to the high thermal efficiency of a modern diesel. If you watch a modern HDi / TDi they will cool by them selves at idle and only generate heat when working against a load. This system produces cabin heat in that case when required by the heating controls.

Not sure about buying a part-harness...

Thanks Zion

That makes sense about the auxiliary heating glow plugs. I am going to pop in and have a look at the wiring damage this afternoon, electronic technician to trade so repairing the cabling is easy enough, but a loom section makes it easier. 

My Partner has always ran with the temperature gauge showing on the low side and arguably it doesn’t blow particularly hot air, warm air yes, but not so warm that you ever need to turn in down in the winter (my rear van section is stuffed with loft insulation and fully boarded (all doors, roof, sides, and floor). 

Taking the above into consideration do you think that my Partner has an underlying issue that is causing the auxiliary heating (glow plugs) to be on all the time instead of for a few minutes after start up, hence the heat damage to the loom. 

Kind Regards 

Tom

[Sol]

Nice one Tom, I'm a controls engineer, I get ya.

I would think you have a point, maybe the main stat is stuck open which would mean loooong warm up time and if the heating is selected in the cabin, the auxillary heating would never go off. Good call.

It can be disabled in the BSI using Lexia 3 and DiagBox till you get to the bottom of this, and that would be well worth having for diagnostic reasons. Not much can touch it for accuracy over generic tools.

[Soarer]

That will be the auxiliary heating mate. It is a kind of glow plug setup. It's meant to help heat the cabin when outside temps are low and coolant is cold, due to the high thermal efficiency of a modern diesel. If you watch a modern HDi / TDi they will cool by them selves at idle and only generate heat when working against a load. This system produces cabin heat in that case when required by the heating controls.

Not sure about buying a part-harness...