24v disaster (1 Viewer)

[graymudder]

The BJ42 is a 24v truck and from what I can gather the PO tried his hand at merging 12v systems. The result is not pretty. I have 2 un matched 12v batteries on which, one battery is supplying 12v to my headlights (not sure how he tapped into the existing harness), winch is a 12v 8274 tapped into the same 12v battery, along with an assortment of aux lights, power seats, radio, and other gizmos all attached to the same battery. On the other 12v battery he has connected a solenoid for the glow plugs (12v)

Now, the bazards do not work, the fan switch only has one working speed, horn is a no go, wipers are very slow. There was a switch (6) panel (12v) installed but could not determine what they were used for. Plus the indicator lights where always on. Glow plug light not working .

I disconnected the batteries and charged them individually.

So now comes the questions....

I was thinking of fitting 2 (12v group 51 batteries) on the driver side I believe the tray is large enough. 1 DC to DC charger ( Redarc BCDC1250 ) can handle from 9 to 35v input and charges a 12v aux battery. The model also accepts dual inputs from solar and source.

So I will have 3 batteries 2 in series and 1 aux for my 12 volt systems


Does this make sense. naturally I will redo a chunk of the harness..

I looked at Redarcs voltage equalizer solution buy at 700 CDN its the same price as the BCDC charger..

 

[hj 60]

Did it help to charge them because if it works maybe it only needs two new batteries and a battery equalizer. (or go to one 12v if starter is 12v)
Probably half of it is still 24v (but nothing is connected to 24v?) and then the blower is only half speed, but works, the horn is cheap to replace with 12v and the wiper engine is more of a job to replace with 12v motor but fast speed should be normal speed or a bit below in 12v?
Hazard blinker is quite easy to replace with 12v, if it is always on maybe it is a sticking 12v but probably a 24v not getting enough volt to release again.

Or go back to 2 batteries and 24v, then the other half has to be replaced: starter motor (?), lights, winch,aux lights, power seats, radio, glowplugs+solenoid.

Keeping is half 12v and 24v is not optimal but it seems to work (slow) at the moment so why not, I think the easiest is going to 12v because most of it is done or maybe I dont understand and it still is 24v from the batteries? (so is starter 12 or 24?)

Anyway if it is still 24v (for the starter) then a 24v converter to 12v is the best option I think, no extra third battery, and I had a third but then it fails and so on, (less is better to me)

 

[kevin in okinawa]

THAT SOUNDS LIKE AN AWFUL MESS; GOOD LUCK MY FRIEND.

 

[FatalErrorStu]

I thought my setup from previous owners was bad, this sounds like a total disaster :-( I would try to put it back to how it was originally, if possible. If you need some reference info than I can look at my wiring but it seems each one of these Land Cruisers is unique. Mine is a 1978 BJ40, 3B with what I believe is BJ42 wiring added.

I tested that both my headlights are getting 24v but I did hear that some models do have 12v headlights? I think I saw it somewhere on this forum.

Stuart.

 

[roscoFJ73]

Go back to stock. This will be one of those that is always getting flat batteries and other weird stuff if you dont.

 

[Freewheel]

Canadian 24 volt HJ and BJ60s had 12 volt headlights using a center tap system (search evil center tap on this site for info) It may be that your headlights are still wired stock Canadian, and that you have a mainly 24 volt truck that someone has added a bunch of 12 volt stuff to. (with some other stuff like your fan and horn that have just failed in some way. The fan has a 4 stage resistor that uses 4 coils of resistor wire to give different fan speeds. They are fragile and tend to break one by one, each break taking out a fan speed... Last time I checked, the fan resistor was still available OEM.
Wipers could need to be removed and the pins greased.
You'll have to take a multimeter to each of these items and see what voltage is being supplied to them. If it's 12 volts you may have a problem with bastardized wiring, if its 24, you may just have to start fixing or replacing the accessories.

I've not done anything like your 3 battery plan, but it seems like it could be an effective way to clean up the 12 volt side of your truck.

Good luck. It sound like a big project, but it will be quite fulfilling to straighten it all out...

 

[Loober]

I set my 24v up with a 12V source off a center tap with a Vann Guard equalizer. I kept all the stock stuff 24v and just use the 12v for aftermarket accessories like gauges, radio, etc. I did it all myself so its clean and I know where it all goes. Even with mine I can see how daunting it would be for the next owner to understand it, just because there is a lot going on, so I'd imagine its even more scary if it was hack job from the get go. Assuming its done right with the equalizer it works fine, I've had this setup for 4 years, running a fridge over a night and my batteries stay within .1V of each other.

But I am planning to do what you mentioned with the 3rd battery using the redarc, more for a piece of mind and to allow the use of 12v solar to recharge the aux battery. I searched for a 24v solar option, there isn't anything available that is compact enough like the 12v options. I am probably going with the new wave of lithium batteries that are much lighter and have more capabilities.

But I'd say rip it all out and start over whatever route you go, nothing worse them chasing an electrical gremlin trying to figure out what someone else did.

 

[FatalErrorStu]

Some very nice answers here, also gives me ideas how I deal with having 12v accessories in the future. I was also thinking about a 3rd battery, I guess there is space in the engine bay still. This is a distant project for me I guess. Good luck graymudder, if I lived in Canada and somewhere close, I would happily help you out.

 

[graymudder]

Thank you for your comments. Food for thought. However I have been trying to find 2 batteries that would fit onto a single tray for my 3 battery setup. However, in order to get the recommended energy, the batteries would not fit onto a single tray, not without some modifications.

So back to a twin setup ( I will be sourcing 2 identical batteries) and a REDARC 25A CHARGE EQUALIZER With this setup I can center tap my 12v for my lights and winch and still equalize my batteries. I also have a 24V converter pushing 70A @ 12V I will use this circuit for my Elockers and Fridge and run a seperate 30A circuit for my ancillaries (Lights, radios )

I might just run my lights off the converter.

Now to get my hands dirty, however it's still cold here in New Brunswick, dropping to -3C tonight and a high of 3C tomorrow. I will post pics as I start getting things done.

Again thanks

 

[Freewheel]

I hate to bring it up, but that seems like too much power to take off a stock BJ alternator, which if memory serves correctly, is about 80 amps. (edit:this 80 amp figure is wrong -see post 12 below) The Mud general rule of thumb is that you can do a DC to DC 24-12 converter to a maximum of 20 Amps from a stock alternator. Have you replaced your alternator with a high output model?

 

[graymudder]

I hate to bring it up, but that seems like too much power to take off a stock BJ alternator, which if memory serves correctly, is about 80 amps. The Mud general rule of thumb is that you can do a DC to DC 24-12 converter to a maximum of 20 Amps from a stock alternator. Have you replaced your alternator with a high output model?

That is an excellent point. However from my understanding, a DC to DC will charge from the 24V starting battery pack. However I have 2 options here.

1. Going with 2 x 12V batteries in a single bank (24v) and a secondary bank 12V with a DC to DC charger from the 24V bank to the 12V bank, so if we have a 50A on the 12V side, it would equate to a 25A draw on the 24V battery bank. I found 2 Group 51 Batteries that fit they are 6 3/8 by 3 7/8 inch each battery.

2. Go with 2 x 12V batteries and use a voltage equalizer. I will also have a 24V to 12V converter rated at 70A for 12V aux systems. I would have my winch tapped to a 12V battery as well as the glow plugs and headlights.
Here I can swap for 24V glow plugs and sell my Warn 8274 winch and get a 24V winch. I rather prefer this method, but I am open to comments. I'm still on the fence..


Question on the Alternator , is it rated a 80A 24V because that is alot of charging power. eqv to 160A 12V

 

[Freewheel]

My memory is not serving correctly. I apologize. It's been 15 years since I was messing with converters and alternator amperages... Should have done a bit of a search first. Its also easy to get messed up between the 24 volt and 12 volt versions.

The quick look around that I just did indicates that a standard 12v BJ42 alternator is either 40 or 55Amps so I would (perhaps dangerously) assume that the stock 24volt one would be half that amperage... which isn't very much at all..

I'll stick to my other figure about 20 amps at 12volts being a maximum safe DC converter size for the stock alternator.

 

[graymudder]

My memory is not serving correctly. I apologize. It's been 15 years since I was messing with converters and alternator amperages... Should have done a bit of a search first. Its also easy to get messed up between the 24 volt and 12 volt versions.

The quick look around that I just did indicates that a standard 12v BJ42 alternator is either 40 or 55Amps so I would (perhaps dangerously) assume that the stock 24volt one would be half that amperage... which isn't very much at all..

I'll stick to my other figure about 20 amps at 12volts being a maximum safe DC converter size for the stock alternator.

That is an excellent point. I will check the specs of the alternator. Thanks

 

[fenwaykid]

Would it not be better to take out the mangled wiring harness and replace it with a new 24v harness?

 

[Earwigg]

Seems like good time to keep it simple as possible.
Convert the headlights to 24v like they were everywhere else.
Get a 24 v motor for the winch.
Then either a small converter for your fridge and stereo or 24v versions of those.

 

[BreckenridgeCruiser]

I have heard about people running a 12v 8274 on 24v without issue... It just runs faster...

 

[MistyGoat]

On my BJ74 the PO installed a 24V->12V converter to run all the accessories, works great but I'm not powering anything intense, the 24V aisin winch being the most power hungry. The batteries are big ol interstate deep-cycle SRM-27's. If the truck sits for a few weeks without running I've had the batteries drain, needing a bit of trickle charge to start again, but the PO also installed a master disconnect switch to completely disengage the batteries to avoid any draining at all. Other than forgetting to flip the disconnect, I've had no issues.

 

[DEADSALT]

12v 8274 on 24v definitely works, it’s twice as quick, watch your fingers and run it half as long.

 

[graymudder]

Well here we are 1 year later and this year its colder than the North Pole. I have to thank the community with such great ideas. Going with 2 12 V batteries, bring everything back to 24 volts. I did have her running in Nov before putting her in the garage. So now I dig into the wiring loom , and rebuild it.

I will post pics as I go wish me luck and some heat its forecasted for 4 or 5 Celsius or 41 F and that's the hottest for this week and weekend.

 

[FatalErrorStu]

Well here we are 1 year later and this year its colder than the North Pole. I have to thank the community with such great ideas. Going with 2 12 V batteries, bring everything back to 24 volts. I did have her running in Nov before putting her in the garage. So now I dig into the wiring loom , and rebuild it.

I will post pics as I go wish me luck and some heat its forecasted for 4 or 5 Celsius or 41 F and that's the hottest for this week and weekend.

Good luck mate, hope it all goes to plan!