Charging woes-SOLVED

So I have now finally(long story) replaced the alternator.

I have also put in a new regulator.

It is still not charging, light in the dash is on and only have 12.5volts at the battery when running. I have tried new and old regulator.

What else can I check?

 

Lamp comes on with igntion on and then stays on, as not charging, so yes think it is working correctly

 

Very occasionally mine seems to need a good blip of the throttle to get it going. Possibly being "new" the brushes won't be making good contact, particularly if you bought a so called reconditioned one like I guess mine once was and the commutator wasn't replaced but the brushes were...

 

fan belt tightness?
My alternator has a faulty diode or 'electricy bit' in it which means the G light doesn't go out until I really rev the engine.
It still charges the batteries, but will need changing at some point.

Is there a good auto electrician you can call?

 

A cheap but worthwhile check.... is your dash bulb is 2 watt or greater

Apparently if the wattage on the bulb is too small there is insufficient current to excite the windings.

@zedders - no commutator in an alt, slip rings is what you mean

 

Alt is a new one not refurb(apparently)
fan belt is tight
dash bulb is same bulb as was in there when it used to charge ok.

ignition switch was replaced recently?

not going to call an auto electrician

 

Try it with a small bulb connected straight across the alt light output and the battery +ve. Does it out quickly? Try changing the dash bulb for one of slightly higher wattage.

 

So from the blue wire to the battery? Engine on or off?

 

No, one side of the bulb to the small tab connector on the alternator that the (possibly blue) cable is normally connected to. Other side of the bulb to the battery +ve. You'll have to get someone to start the engine while you're down the back. Don't let the alt light output short to ground while the engine's running.

All you're doing is bypassing the mile of wiring to the front of the van to eliminate that as a cause.

Trying a new dash bulb is another option. The small "tickler" current flowing through the bulb is what makes the regulator kick in and start the alt generating power.

 

You can take out the brushes and check they are not damaged. From personal experience they are easy to snap so they work for a bit and then give up as the stump wears out. Also some commutators have big wear grooves in them ( lke mine...) so brushes can get hung up on the plastic insulation of the commutator.

One day I will find the spare commutator on a day when the alternator is out of the bus..
Also check the big wire from the alternator is properly connected as if the terminals are a bit loose the light glowas a bit and the battery fails to charge.

 

right got you. pulled alt out now to check the wiring loom and its all good. i have also done a continuity check from the engine back to the bulb and its good as well.

I also checked the ignition switch from terminl 15 to terminal 30 and that checks good as well.

I can only thnk that i have a bad (new) alternator or a bad regulator (also new) i have tried the old reg and its the same so i think it may be the alternator that is bad.

 

its a new alternator

 

Dodgy earth strap/ terminals?

 

Sounds good. It may be the regulator, as that's what starts things going. I experimented with my refurbed alt on the bench, and there was a variation in the time it takes for charging to kick in depending on regs and the wattage (ie current flowing) of the alt bulb. Might be worth trying another.

I'd doubt it's the alt itself, as they're so simple inside. But...you never know.

 

Proper *****ed it now, took new alternator apart to check the brushes and it's a cheap crappy plastic holder and it broke as I pulled it apart.

Think I will have to use the new brushes soldered onto the old brush pack set

 

All checked and nice tight

 

Wiggle all the fuses in the fuse box, sounds like you have an electrical issue, which may not be your alternator

 

Still not working, going to get alternator checked. Maybe try another new regulator. All wiring checks out fine

 

Try a charge light in the engine bay straight off the regulator