Old MQ, what should i do?

[taslucas]

I have a MQ SWB SD33 24volt. It only has 230 000 k's and is mechanically sound. Pulls like a trojan and only blows smoke at full blast. Body it rough with a bit of rust etc.

Problem is the dual battery 24volt system isnt reliable. Batteries are a bit old but even when both fully charged it plays up and will blow a solenoid i think its the either the glowplug solenoid or something to do with the voltage equalisation set up (its on the driverside wheel arch)


Im thinking i have three options but not sure on whats involved and i dont want to spend too much. I just want it to be reliable and be able to leave it for weeks at a time.

1) Buy 2 new batteries. Clean up the wiring, earths etc. Freshen up the voltage equalisation (whatever its called!). Make sure i drive it on a regular basis to keep the batteries fresh and topped up. Disconnect when not in use. Maybe even get a solar trickle top up charger.


2) Convert to 12volt system. I think this involves changing: Starter motor, Glowplugs and alternator. Anything else? As its unrego'd i only need headlights, 12volt accessory outlet and CD player.


3) Is there any reason why i cant use a single 24volt battery? Providing it has enough cranking amps.
Could i change the paralell wiring from the existing two 12volt batteries to suit a single 24 volt battery?

I really dont know much about the 2 battery system!
So which one would be the best (read cheapest lol) option.

Any input would be great......

[the ferret]

Ive never seen a 24 volt battery!!, but to change it all to 12V, you need to swap, altenator, starter, lights, dash globes, edic motor, all the relays, glo plugs and timer, wiper motor flasher unit, heater fan,all over to 12V, huge job and there are probably more that I havn't thought of. lol
Best to run two good batteries and a battery conditioner when not in use.
Every now and then, swap the batteries over.
Cheers, the ferret.

[taslucas]

All the globes have 12volt written on them? There has been a CD player put in it at some stage. Its a 12volt cd player so im thinking maybe whoever did it just stole 12volt from one battery and therefore the system is unbalanced and not working properly. Ive heard that if the batteries dont have the same charge then they fight each other

24volt batteries can be found in trucks (thats all i know lol)

[the ferret]

I think from memory, the radio and the dash cluster are all 12 volt. and they come off one battery, this is probably why one dies.
A redarc 24 to 12v reducer would be a good idea I think, and then run all the 12v stuff off that, that way the draw would be even and the two batteries would be sharing.
They would then get the proper charge.
2 twelves hooked up in series for 24V would have more cranking amps than one 12V on its own. N70Z are the ones for your MQ
Yendor would be the best person to put you straight I would say, he's bound to pop up anytime now.
Cheers, the ferret.

[MQ MAD]

24 V patrols are great IF the batteries are upto the task
Never replace one battery always do both,even IF one battery is still good,replace both
Go buy 2 new batteries N70Zs as mentioned can be had for not much more than $100 each
IF you dont use it often,buy either a battery isolation switch or disconnect 1 battery
The 24V cars have 12 V radios,the radios unless bodgied up in the wiring usually dont draw power when the ignition is off,if it works all the time,hook it in the harness properly or run a switch in the radio power feed wire
Swapping to 12 V is alot involved as mentioned, and im sure there is more to do,but not worth the effort,the bits you need will cost abit,even 2nd hand
You can get mobile sparkies ,and depending on location there callout fee usually entails the first 15 mins or half hour, unless its a major issue , its found pritty quick
Leave it 24 V ,new batteries, get it looked at,and you should be fine for years

[moose maverick]

Yeah negative on the 24 volt batteries in trucks mate. Some of the bigger japanese trucks and a lot of the european trucks run 24 volt which as the ferret said is 2 x 12 volt in series. Way too much work changing to 12 volt better to leave as is.

[aussiemale]

Obviously I'll have to put in my 2c worth, I have a MQ and a MK (as per "Bryan's MQ/MK Build). The MK is 24 volt, the MQ is 12v.
Changing from a 24 to a 12v can be a bit of a pain as every bulb etc will need to be replaced, best way to find if the vehicle is a 12 or 24volt system is to look at the heater blower (passenger side) will state what it is.
If it is 12V then the 2nd battery is for accessories, 24v means both are for starting. A 12volt battery won't start a car if it's 6volts, as a 24volt battery (2 x 12volts) won't start if only 12volts are available so if one battery is buggered, the other needs replacing and as pointed out above, replace both otherwise one will feed off the other. Stuff around too long and the starter motor will start getting affected due to having to work harder to get the CCA to crank over the engine.
Batteries are quite complicated however one way of looking at it is;
Batteries have two parts to it, CCA (Google it), and Voltage.
CCA is like Fuel, Surface charge is like Oil,
Diesels need (3ltr and higher) a minimum of 660CCA to Crank over the engine.
If you don't have CCA (too small a battery or a dying one) it's like you've got an empty tank, doesn't matter how much surface charge (oil in the engine) you have, won't be enough to start it
If you don't have the surface charge it's like having no oil in the engine, doesn't matter how much fuel (CCA) you have, it won't start.
CCA and Surface charge (the voltage) work hand in hand, CCA is like a sponge that holds the surface charge and the surface charge maintains the CCA. As soon as one gives way, the other will fall as well.
On average you should get approx 7-10yrs from a battery (under normal conditions) however expect less if you use this forum LOL.
I personally only use optimas as there are no plates to be cracked.

[MQ MAD]

On average you should get approx 7-10yrs from a battery (under normal conditions)
.

This will be determined on the cars charging system
If the charging system is failing somewhere you could be lucky to get a day,a week,a month or a decent trip
Batteries new usually only come with a 12 month warranty
Batteries also have a cranking time frame, go crank a diesel for ages and itll flatten a battery real quick
We just replaced the battery in the GQ , it was well over 10 years old
The trick with the old diesels,is get the biggest,maximum CCA you can fit in the battery area


Give ya an idea how much CCA a diesel uses, a battery that wont turn over an old SD33 diesel will start my ol V8 ford

[aussiemale]

Batteries new usually only come with a 12 month warranty


Be also aware that you use the correct battery, batteries are supplied for what is stock in that vehicle. As soon as you add more things creating a larger draw, the alternator may not be able to supply enough power to prevent the battery from cycling (charge, discharge, recharge etc) and the calcium batteries available now don't like that at all. If you replace the stock standard battery that was supplied with the vehicle with the exact same and you add a winch, fridge, GPS Radio. You'd of voided your warranty due to the extra load (bit like putting a V8 into a Bambina and forgetting to change the fuel tank size). Best thing to do is get advice from an auto sparkie as they'd know what you'd need, most likely you'd be recommended to get two batteries. I'm using two Yellow top Optimas (well, when I finish my project) and one is for the starting, the other will be hooked up in parallel so I've got more reserve capacity.

[taslucas]

Cheers guys. I think ill save up and get some new batteries and give the whole system a good look over.

[aussiemale]

Tas, get an auto sparkie to look over it, I'm sure there's someone on this forum that would know a good local one to you and may only cost you a slab of pisss

[GQ TANK]

The concern is "that if the batterys are fully charged it will blow a sonoid or something"

To confirm if you have a 24 system or 12 volt with a second battery.

Get a multi meter and set it to volts.

Measure between the negative of the first battery and the blcok of the engine (you need a ground) - any volts.- any volts (more then .5 of a volt - around 11 - 12 volts).

Measure between the negative of the second battery and the block of the engine (you need a ground) - any volts (more then .5 of a volt - around 11 - 12 volts).

I you have volts then you have a 24 volt system.

In a 24 volt system the batterys are connected in series

Battery 1 - Negative to ground, Positive to the negative of battery 2, the Positive termonal of battery 2 will be at 24 volts (when measure to the engine block)

[taslucas]

The concern is "that if the batterys are fully charged it will blow a sonoid or something"

To confirm if you have a 24 system or 12 volt with a second battery.

Get a multi meter and set it to volts.

Measure between the negative of the first battery and the blcok of the engine (you need a ground) - any volts.- any volts (more then .5 of a volt - around 11 - 12 volts).

Measure between the negative of the second battery and the block of the engine (you need a ground) - any volts (more then .5 of a volt - around 11 - 12 volts).

I you have volts then you have a 24 volt system.

In a 24 volt system the batterys are connected in series

Battery 1 - Negative to ground, Positive to the negative of battery 2, the Positive termonal of battery 2 will be at 24 volts (when measure to the engine block)

Yeah its definately a 24 volt.