Cigar lighter in W211

[Ian B Walker]

Steve ditch the 211 and use Carols 124, you know it makes sense

 

[Gollom]

This is why I said that if this only blows when the car is running, then it is one of the over voltage problems that can affect the 211

Sounds Nail On Head, given all the evidence. Thanks guys

Steve

 

[Gollom]

Has the unit been tried in another car since it blew the fuses? it could be that removing it from one car to another has caused a short in the cable or unit.

It might also be worth checking the voltage output from the socket just in case that has caused a problem with the Satnav, unlikely though.

But with 2 different units? Does sound as if it is the over voltage issue.

 

[television]

Its hard following parts of this tread so this is what you can and cant have.
Cant have.
Car 1 engine off, plug device into cigar lighter and blows the fuse built into the device thats plugged in. replace device fuse and plug into car 2 and all works OK as the nominal voltage is 12.5 volt max with engine off.

If it does blow the fuse with engine running, then it can only be over voltage.

The only other thing that I can think of is.
Cigar lighter sockets can be slightly different in construction. if the center pin in the socket is higher in the car, it could be possible that there is a fault within the device plug that allows the spring loaded moving center pin to short out something within the device plug, opening the plug and pushing the center pin would show if this was the case.

 

[MBManInKen]

But with 2 different units? Does sound as if it is the over voltage issue.

I'm not entirely convinced - but if you have a multimeter, you can check the voltage at the socket with the engine running. I have no schematics for the W211, but wouldn't this be a regulated circuit?

Also, the power unit should be able to cope with at least a 10% difference in voltage. If it is an issue of a slightly higher voltage, the current going through it should not be that much higher that it triggers the fuse...

 

[Dieselman]

And even if the output voltage did float up, it should damage the Satnav, not blow the fuse.
More likely it would blow ht eheadlight bulbs first though.

Try the satnav in a different car then report back.

 

[television]

And even if the output voltage did float up, it should damage the Satnav, not blow the fuse.
More likely it would blow ht eheadlight bulbs first though.

Try the satnav in a different car then report back.

Not all Sat Navs run on 12v, many have a dropper device built into the plug or lead, some Navman units are only 3volt

 

[Dieselman]

My point was that if the vehicle voltage increased, the bulbs would be the first casualty.

If the Satnav has a regulator device, then that may be toast.

 

[Gollom]

Thanks all - you guys are da bomb!

My money is on the over voltage issue, but I'm not able to get the car in until back of September (work very busy plus holiday/French GTG!!)

Looks like I am going to have to live with it until then

WARNING - VERY DUMB QUESTION

The satnav thing fuse (it's not the actual satnav but rather a brodit holder thing with a small speaker and captive power lead) is 1.5A and the ipaq charger is 2A. Would it hurt if I just doubled the fuse size for the moment?

TOLD YA IT WAS DUMB!!

 

[television]

Thanks all - you guys are da bomb!

My money is on the over voltage issue, but I'm not able to get the car in until back of September (work very busy plus holiday/French GTG!!)

Looks like I am going to have to live with it until then

WARNING - VERY DUMB QUESTION

The satnav thing fuse (it's not the actual satnav but rather a brodit holder thing with a small speaker and captive power lead) is 1.5A and the ipaq charger is 2A. Would it hurt if I just doubled the fuse size for the moment?

TOLD YA IT WAS DUMB!!

No way do you change the fuse rating = suicide

 

[MBManInKen]

Malcolm is right - the fuse serves a clear purpose: to protect the circuit from a level of current it can't cope with.

Changing the fuse for a higher-current one puts the circuit at jeopardy as it will allow a current to flow through it that is too high for the circuit, so don't do it.

Even with a small over voltage, the fuse should not blow though, that's the part that baffles me (admittedly, the current going through the device will be slighthy higher at higher voltage (since the circuit's resistance remains the same), but that should not be of a magnitude to blow the fuse...

 

[television]

Fuses (20mm and 1") come in different forms, you can get Quick blow, slow blow, anti surge, alert, time delay and many more.

The next size up is 2A

for £5 you could buy a multi meter and all would be known

 

[MBManInKen]

Yeah, I had been thinking about the possibility that for example the fuse had been replaced by a slow one, but it still all boils down to marginal differences between the two usage scenarios, which seems odd as an explanation for this behaviour...

 

[television]

Yeah, I had been thinking about the possibility that for example the fuse had been replaced by a slow one, but it still all boils down to marginal differences between the two usage scenarios, which seems odd as an explanation for this behaviour...

Phew, there is another situation where if car A had a faulty cell in the battery, that could pull down the running voltage and mask the fault. And the car with the good battery would produce the fault

Many plug in devices maybe too marginal in the fuse rating.

A multi meter for £5 would tell all

 

[MBManInKen]

A multi meter for £5 would tell all

This is good advice and there is a good chance Steve could know someone who has a multimeter anyway.

Measuring the voltage seems like the logical next step...

 

[sjr]

soooo glad i found this. just spent 2 days pulling fuses from the boot and dashboard. the manual doesnt mention the bonnett box