MQ 24 volt only reading 12 volts???

[samnjosh26]

Hi hoping there is someone who can help me I have an MQ the alternator isnt charging and I can only get a reading of 12ish volts. Ive had it for a good 9 months and have had no troubles with it until recently. Im not sure how long its been giving the 12 volts i only bought the multimeter when the batteries were goin dead. Could the 12 volt reading have something to do with the alt not charging. Any ideas at all would be great. BTW the voltmeter on the dash says over 24 volt?? I can give alot more info about the car but im not sure whats useful so just say what u need and ill give it thanks in advance

[MQ MAD]

The dashes read over 24 V , means its all good at those volts
The 12 V dash in my ute reads 14 odd volts
Being 12 V ,in a 24 V rig it wont start at all, there wont be enuf power even to glow the glow plugs as they will be 24 V
The other issue many have with these 24 V is they skimp out on replacing both batteries when one starts to die
You can replace just one, but its best to do both , it hurts the wallet doin this, but the batteries are both even and shouldnt draw more from one or the other
If its not charging, id get the alternator checked out and depending how long the issue has been there you could be up for two new batteries as well

Many people hook up gear like radios, and other devices straight from one battery this helps kill one battery quicker than the other
There is some 12 V power leads in the harness in these old rigs its best to source that wire and draw the 12 V power from there instead of hammering batteries

[GQ TANK]

How many batterys do you have. 2?

Where did you measure the 12 volts was it across a battery?

Are they connected in series - negative of battery one to the chassis, the possitive of battery ` to the negative of battery 2 The positive of battery 2 to the stater / alt etc.

To check with a 24 volt system. Gound the negative lead of the multi meter to the chassis / motor. Measure battey 1 positive - is it 12 volts?, measure battery 2 is it 24 volts?

Does the truck start - repeat the above test


Someone may have converted the truck to 12 volts in the past.

[samnjosh26]

Thanks MK Tank reading 24 volts now I was measuring the batteries wrong the stupid mechanic was aswell he told me my beast only runs on 12 volts and my in dash volt-meter is stuffed!!!

[GQ TANK]

Your welcome