How can you tell 12v from 24v components?

yorvik · Dec 25, 2014

Ok, I need some help here, cause I can't find the answer anywhere.

Lets say you have this instrument cluster and the 12v or 24v sticker along with the part number is worn out.
Also, the lamps are missing, so you can't read their voltage engraving as well.
How can you tell the voltage of it? How to measure it?

Darkwood · Dec 25, 2014

You can't. If you know the nature of the power either AC or DC you can always connect it to a 12v battery if DC and see if it works but the power maybe just for the lamp or volts free relay if it has one .... what exactly is the power for?

telectrix · Dec 25, 2014

agree. try it on 12V first.

Robotstar5 · Dec 25, 2014

If the fuel gauge uses a standard resistance mat type feed which is 0 ohms when full, put 12V across gauge, if it only reads half full it's a 24V cluster.

Isn't the part number on the box next to it?.

steve50 · Dec 26, 2014

Mercedes VDO Instrument Cluster 6"Vintagetruck 911B Unimog 406 416 Bus 309 408D | eBay

can't you ask the seller

Geordie Spark · Dec 26, 2014

telectrix said:
agree. try it on 12V first.

Bowlox!!!

Shove 24V through it & if it starts to get warm and smoke you'll without any doubt know it's a 12V job!!

telectrix · Dec 26, 2014

typical geordie. hit it with a sledgehammer and if it breaks it's faulty.

Besoeker · Dec 26, 2014

I think the Unimogs used 12V batteries.

shanky887614 · Dec 26, 2014

its 24v, if you see the magic smoke it has magically become a 12v device

Geordie Spark · Dec 26, 2014

telectrix said:
typical geordie. hit it with a sledgehammer and if it breaks it's faulty.

It's a method that hasn't failed me yet.

ElectroChem · Dec 31, 2014

Geordie Spark said:
It's a method that hasn't failed me yet.

That's how I was taught. Whack it with a hammer, either it will start working or it was stuffed anyway!

PEG · Jan 6, 2015

It is 12 volt.
I know this for a fact,for two reasons.
1) I have done a fair bit of work with,and on the entire Unimog range,including the 911. You can specify almost any variance from new,including 12 or 24 volt,usually being an uprate to 24,on smaller,older models. But this one is for a 12 volt model.
2) The other reason is simpler.......it says so,three lines down,on the item description.....:icon12: