Hiya
I’ve always seen them aside of articulated tankers on the roads, but what do those 4 green LEDs mean just behind the cab on the unit? It’s only on the tankers i see them so I thought it was specific to that, but don’t know what they are, if anything special?! 
its the warning system for the battery cut out, light on battery connected light off battery disconnected, normally on hazardous load tankers such as fuel ect. well thats what i have been told it might be wrong thou have to wait and see someone is bound to put me right 
peteandbrenda:
its the warning system for the battery cut out, light on battery connected light off battery disconnected, normally on hazardous load tankers such as fuel ect. well thats what i have been told it might be wrong thou have to wait and see someone is bound to put me right
absolutly spot on dear chap. its very much against the rules to load a petrol tanker with the electrics still on, only the tachograph will work whilst everything else is isolated
Thank you for your helpful posts 
Another answer answered
User your brains what do you think it means
Okey-Didley-Dokely:
User your brains what do you think it means
Considering I don’t have a HGV licence and don’t get close enough, I actually thought it was some safety light saying all was OK on the tanker, either that or a reminder that the tanks were full.
It’s easy for you to infer you know and treat everyone else as ‘well you should know’ ‘because it is’ as reasons but if I don’t know how am I going to find out without asking?! 
Saratoga:
Okey-Didley-Dokely:
User your brains what do you think it meansConsidering I don’t have a HGV licence and don’t get close enough, I actually thought it was some safety light saying all was OK on the tanker, either that or a reminder that the tanks were full.
It’s easy for you to infer you know and treat everyone else as ‘well you should know’ ‘because it is’ as reasons but if I don’t know how am I going to find out without asking?!
I thouight everyone on here kew everything
i have been driveing for years and i am still learning . you still see things for the first time . if you think you know it all well you have got a prob . me thinks .
Like Boost , this is new to me as the trucks over here in
germany do not have these lights we have a cut out switch
yes which turns off every thing except for the Tachograph,
If I remeber correctly many years ago in the UK the night
heaters had to be removeable when loading or am i mistaken
This is one for D,D; 
brit pete:
Like Boost , this is new to me as the trucks over here in
germany do not have these lights we have a cut out switch
yes which turns off every thing except for the Tachograph,
If I remeber correctly many years ago in the UK the night
heaters had to be removeable when loading or am i mistaken
This is one for D,D;
on the tankers i drove they all had a key to turn on/off. this was removed as soon as vehicle was delivered to our place and kept in the office.you was never alowed to use a night heater on our petrol tankers.
"quoteI actually thought it was some safety light saying all was OK on the tanker, either that or a reminder that the tanks were full.
there are sight glasses or gauges for each compartment on the tanker. there are various methods to tell if any product was in or left in each comparment(pot) and the product markers you see above each pot are done by hand.
also it takes on average less than 20 minutes to load a tanker with petrol and derv (using 3 loading arms at once)
hope that helps explain a little
peteandbrenda:
its the warning system for the battery cut out, light on battery connected light off battery disconnected, normally on hazardous load tankers such as fuel ect.
With these LED’s lit, you will also usually find the front top marker lights will also be illuminated
I used to drive an ex Hoyers Scania day cab unit S reg). The side lights were permanantly on (like on volvo cars) I assumed that was part of the safty system
Semtex:
I used to drive an ex Hoyers Scania day cab unit S reg). The side lights were permanantly on (like on volvo cars) I assumed that was part of the safty system
The top markers are a visible warning, as well as the green led side markers, to let you know that the electrics havent been isolated.