wrecker generater question

[jeep thing]

okay i installed used generater,but batteries wont charge,i down loaded testing info on charging system ,the truck passes all tests says generater is good but no charge to batteries, now somebody told me i have to excite the generater is this true and how do you excite the generater if this is true

 

[jwaller]

I have heard of that process but never had to do it. is the connection from the gen to the batteries good?

 

[AMGeneral]

It's called "polarizing" the generator,same procedure as on older farm tractors,run a hot wire from 24V+ and momentarily touch it to the Field terminal B on the generator connector at the generator itself.

 

[NDT]

Assuming your wrecker is the one in your picture, it will have an alternator and you don't polarize those. If you are putting 28 volts to the batteries and they will not take a charge, it's likely your batteries are shot.

 

[jeep thing]

Assuming your wrecker is the one in your picture, it will have an alternator and you don't polarize those. If you are putting 28 volts to the batteries and they will not take a charge, it's likely your batteries are shot.

it is the one in the picture,i was told it is generater, i have 24 volts eveywhere but not 26 - 28 volts, according to download info generater should put out 24+ to 28 volts when truck is running

 

[jeep thing]

Assuming your wrecker is the one in your picture, it will have an alternator and you don't polarize those. If you are putting 28 volts to the batteries and they will not take a charge, it's likely your batteries are shot.

not getting 28 volts to batteries,24 volts through controll box ,24 volts everywhere, just not getting 26 - 28 volts anywhere

 

[cranetruck]

You can adjust the output voltage of the alternator, remove a pipe plug with an allen wrench and make the adjustment. PS mag section is not available, but I uploaded a pic of the procedure one time.
Good or bad batteries, the charging voltage should be 28.5 volts...

 

[1958 M274]

As others have indicated, if your truck is the one in your picture, it should have a 60 amp alternator with an internal regulator.

Using your multimeter, check your batteries with the truck shut off. Should be around 24-25 volts with good batteries.

Start the truck and check voltage at the batteries again.

If you show no increase in voltage, check the output directly at the alternator. Spec is 27.5 volts, but for all practical purposes as long as you're 26+ you should be ok. You can adjust it if necessary.

Once you're sure the alternator is charging but you're not getting charge to the batteries, unplug the wire from the volt gauge in your instrument panel. Check voltage here.

If you're getting appropriate charging voltage at the alternator and at the volt gauge in your instrument panel, but not to the batteries, it is likely that the charging system relay in your protective control box has failed. In my experience this is the most common charging system failure on M809 series trucks.

Good luck!

 

[cranetruck]

Here is the wiring, including the protective control box. If the engine starts, the control box is probably not the problem with the charging.
27.5 VDC for charging is actually a little low...

 

[jeep thing]

As others have indicated, if your truck is the one in your picture, it should have a 60 amp alternator with an internal regulator.

Using your multimeter, check your batteries with the truck shut off. Should be around 24-25 volts with good batteries.

Start the truck and check voltage at the batteries again.

If you show no increase in voltage, check the output directly at the alternator. Spec is 27.5 volts, but for all practical purposes as long as you're 26+ you should be ok. You can adjust it if necessary.

Once you're sure the alternator is charging but you're not getting charge to the batteries, unplug the wire from the volt gauge in your instrument panel. Check voltage here.

If you're getting appropriate charging voltage at the alternator and at the volt gauge in your instrument panel, but not to the batteries, it is likely that the charging system relay in your protective control box has failed. In my experience this is the most common charging system failure on M809 series trucks.

Good luck!

thanks for the help,the truck is the one in the pic, it says generater on the generater,it is 60 amp, i had the generater tested it is bad so a bunch of people have suggested switching to a 1 wire 24 volt alternater ,so im trying this, the 24 volt alternater is half the price of the original 24 volt generater,batteries are being charged with triccle charger,if this works when i start the truck i will post up, it saves money and only took me 45 minutes to modify the brackets to work

 

[jeep thing]

fixed i think

okay i put in the 24 volt alternater and i have 27.5 volts everywhere,ran the truck down road with lights on for 15 minutes when i got home turned her off she started right up,so i assume the fix worked and way cheaper then standard 24 volt generater,new generater was 400 - 600 bucks depending where i looked from tnj murry to boyce, 24 volt one wire alternater 170 bucks plus pulley for a total of 220 bucks plus some time to work out spacers to fit different size alternater

 

[Csm Davis]

pics please

okay i put in the 24 volt alternater and i have 27.5 volts everywhere,ran the truck down road with lights on for 15 minutes when i got home turned her off she started right up,so i assume the fix worked and way cheaper then standard 24 volt generater,new generater was 400 - 600 bucks depending where i looked from tnj murry to boyce, 24 volt one wire alternater 170 bucks plus pulley for a total of 220 bucks plus some time to work out spacers to fit different size alternater

 

[firefox]

He doesn't need the picture for the alternator. There is no need to excite it