just fitted a alternator

[dagboyblue]

just fitted a alternator -

charging light goes off as normal, but after running the engine for half hour or so the battery starts to fizz??

its a alternator from machine 7 so has a internal regulator

is this because the battery is on its way out??

cheers

d

 

[Araon]

or the regs bolloxed....

do you have access to a voltmeter

 

[dagboyblue]

yes mate - am i looking for a regular 12v?

 

[Araon]

Voltage across the battery with engine running should be a little over 13V it may start a little higher 14 ish if the batteries low

 

[dagboyblue]

cool 8)

 

[Loxy]

Telltale sign of your regulator being knackered is your lights getting brighter at higher revs and quicker moving wipers also things start to blow like revcounters etc - ask me how I know

 

[dagboyblue]

run the engine and there is a 12v current at the B+ point?

if the alternator is giving a charge throughout the range , could this mean a old battery can't cope???

 

[dagboyblue]

right checked again

seems like the negative terminal on the battery is starting to melt ??????

also noticed that the earth from the alternator is not hooked up - i can't see this causing the problem, as there should be some sort of earth through the alternator stand??

also run the engine with the wipers on - there was no increase in speed if i revved the engine??

the connections i have are B+ direct to battery positive and the d spade terminal to the waring light

don't really want to hook up a new battery and ruin that one

 

[Araon]

Well you can pretty much guarantee the Battery is fubared.....

earth the alternator you cant be sure that the continuity from alternator case to engine case is good but also check the earth strap on the gearbox.... if the neg is melting then you have a potential difference across that cable so replace that clean the battery post and the metal fixing in the engine bay. Is B+ connected directly to batt or via the starter?

D+ going to the dash light, whats the voltage there?

 

[dagboyblue]

got a even voltage over the B+ and D+

tried revving again with the wipers on and i think they are speeding up could this still be the battery fault ? or the reg in the alternator

if its the alternator - I hope machine 7 will do a swap??

 

[67panel]

charging voltage should be 13.8 to 14.2 volts.batt should read 12.5ish when standing best crank engine with out starting first then check .silly question number 78 is batt fitted neg earth :?:

 

[dagboyblue]

hi

yes battery is fitted neg earth

right tried and brand new battery today, same thing started to happen - e.g. bubbling up

so to get the last mile or so home i disconnected the alt from the battery but left the belt on so the fan will keep going - then half a mile later smoke was coming out the engine bay - quickly stopped and checked it out (shitting myself ) and smoke was coming from the alternator "phew" so thats answered my question is it the battery or the alternator

the alternator is f**ked :x

machine 7 said they will swap over just got to reassemble again

just in case i am missing something connections are as follows - b+ to battery positive D terminal to gauge

cheers
D