Just wondering if there is a legend on here that can tell me what sort of voltage I should be getting on my multimeter at the alternator on my 70 series LC ?
I'm having battery issues (bout 80% sure its toast )and just want to rule out the alternator before I go buy a new Battery .
To check alternator function measure the battery voltage with the engine stopped (should be in range 12v to 13v), then start it, rev up a little and measure again (should be 14v plus). Main beam headlights should brighten a touch when you rev up from tickover, or if it's daylight turn on the fan blower to full blast and listen for a slight change in fan speed as you rev up. If there is no obvious voltage rise with the engine running you have alternator trouble.
To check alternator function measure the battery voltage with the engine stopped (should be in range 12v to 13v), then start it, rev up a little and measure again (should be 14v plus). Main beam headlights should brighten a touch when you rev up from tickover, or if it's daylight turn on the fan blower to full blast and listen for a slight change in fan speed as you rev up. If there is no obvious voltage rise with the engine running you have alternator trouble.
Good Luck.
Hi Swoffer,
Hako is pretty spot on with this. But if the battery has a failed cell it may be lower than 12V before starting and only rise a volt or so and not get up to 14+.
Thanks folks . Looking at the price of Batts for these , it may be cheaper if its the Alternator
I probably should have mentioned that I had the battery on a charger for 2 days , it showed 6 of seven green lights but still wouldnt crank the car when it went back in .
Definitely the battery. I've got a battery in my rideon mower that shows 12.5 volts but still won't crank the motor over so I jump start it. They lose capacity over the years and 3 years nowdays seems to be how long they last although the rideon battery is 10 years old...it's so old it was made in Australia!
Replacing your battery.
Think about one of those Spiral Wound AGM Hybrids.
SHOULD last a lot longer and give more while doing so.
With the ALT. I always.
Turn on ign. My guage shows 12.1 to 4v.
Start engine. Coupla seconds it kicks up to 14.1\14.2v
Normally runs around 13.3\4v
ALT fine.
If it don't. get it replaced. rebuilt\exchanged.
A volt\Temp meter are the cheapest things. ALL should have one in there.
Basically.
Just start engine on IDLE.
when all lights out. Just BLIP throttle.
that will excite the Alternator and v guage should jump up to around 14'1.
Try it with yours.
If nothing. Plobaly ded.
Just to be sure. Jumper leads to another battery.
If nothing. your alt needs rewind or something.
PS. IF changing alt.
BEFORE you do. change.
Go on net and look for "electrical re- or Winding Coil services.
They can REWIND what you got to a higher output.
I, and a lot of others I know. ALWAYS did that to our marine alt's on auxiliary motors.
Gives a lot more output in same period of time to battery banks.
I haven't got it now. But when I did. A "towing marine alternator".
Towed behind yacht while sailing.
If ever we stopped near river bank with a decent flow.
I had a 2 leg frame. stuck into bank holding alt in current.
ALL free juice.
I know an ex yachtie mate. Had a spare "shaft alt".
He had AXLES suspension on van. Mounted it to front axle and backing plate.
All the time his wheels turning. FREE. Constant Power going into Van battery's.
.
They are, (were?) pretty exxy to buy. But if you had one....
I've got a Marine wind genny in shed. Silent. but only around 5A.
Hardly worth it with the panels we have nowadays.
but does give output in the dark.
It was. Around $1450. Used for about 13 minths. hmmm.
Try another battery via jumper leads first and see if it starts ok, it could be the starter motor. Also check the alternator belt for tension and that it isn't shiny on the V section or bit chewed out of it.
Check everything before replacing anything:
After my boss had changed 2 alternators, 2 batteries, a starter and on to the 3rd alternator and battery I was given the job to check it out to see if I could figure out what was killing these alternators. It was on a forklift with a V8 cat motor but for some reason only a single belt. Turned out the V pulley was actually shaped more like a U and the belt wasn't gripping the V part at all, only on the bottom of the grove. Further investigation turned up that the new alternators didn't come with a pulley, so they had simply been swapping the pulley to the new alternator. Further investigation showed that the problem had been there for the last 10 yr or more, the driver had only been driving it for 10 yrs but the previous driver said it had regular alternator problems. I did find a shelf full of boxes containing perfectly good alternators that had been pulled to bits by fitters who didn't have a clue what they were looking at once they had it to bits, so it went in a box :lol:
T1 Terry
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Hit the starter button\Key.
If starter "clunks. you got juice in battery. You getting charge.
If lights just "dim" you got a ded battery. Find cause.
Connections first then onwards.
Headlight on. Main beam. Do they hold or dim after a minute or so?.
Door locks?. Air Cond.
ANy load will give good idea,
Basically. If your load Just "stops. Bang, Lights hold beam. it's in the system.
.You have charge.
If light just dim. Aircond comp won't kick in. Doors won't operate.
You have Zero charge in battery.
Take to Tyre place, workshops anywhere.
They'll do a dump load for you. Tell you whether it battery or system.
There's NO point trying to charge a ded plate battery.
It's Something like filling a bucket with hole in bottom.
It don't work Mate.
EVERY car should have a Volt meter in dash.
After a while, YOU know what your electricals doing.
Ign ON voltages. after start Voltage. Running voltage..
It's no different to checking tyres. Oil. Tow bar bolts etc.
Same with Temp's.
THE Scanguage gives them plus.
Torque PRO does too for $20ish and an 0ld phone\Tablet.
But not so precise or as many of.
