Charging problem?, 85 Drover

[-Leigh-]

Just wondering what a typical charge voltage is for my 85 drover! I have a new battery as my old one was stuffed and had my alternator re cond, while my engine is running I put a multi-meter on the termainals of the Battery and can only get a reading of 12.68 v

Was expecting it to be higher then that!?
or is that normal?

Cheers Leigh

[want33s]

Usually between 13 & 15 volts.
When engine is running, disconnect the battery to see if alt is charging or not.
If engine stops alt is dead.

Jas.

[WRXZook]

I thought you should never disconnect the battery (with engine running) because of possible voltage spike damage to alternator diodes and sensitive electronic equipment in later vehicles (although 85 Drover may not have anything much to damage). Just thinking aloud, as I have been out of the trade for a while .

[want33s]

I thought you should never disconnect the battery (with engine running) because of possible voltage spike damage to alternator diodes and sensitive electronic equipment in later vehicles (although 85 Drover may not have anything much to damage). Just thinking aloud, as I have been out of the trade for a while .

If the vehicle has a computer it isn't recommended, but without a computer it is acceptable for the 2 or 3 seconds it takes to work out wether the engine will stop or not.
You can run a car (without computer) for extended periods if needed, without damage to electrics, as long as every available electrical device is used so there is no, for lack of a better term, buildup of energy in the loom.

Jas.

[RockHopper]

12.68v is pretty close to battery voltage so no, your alternator isn't charging the battery. Check with a multimeter at the B+terminal on the alternator and take your reading from there. A good charge rate is anywhere between 13.6 - 14.6v. If you're getting charge at the alt, look for a prob in the wiring between the alternator and the battery. Also, make sure you check all the basics, such as is the fan belt tight enough, and does the alternator light on the dash work when you switch the car onto accessories, just before you start?

[-Leigh-]

Rightio, car dies when i remove a lead from the battery, so therefore I take it my alternator is not producing charge! And with a multimeter i have tried to get a reading off the back of the alternator, Which terminals do i read it off? B+ and there is a choice of 3 terminals all close together!

Cheers Leigh

[want33s]

Rightio, car dies when i remove a lead from the battery, so therefore I take it my alternator is not producing charge! And with a multimeter i have tried to get a reading off the back of the alternator, Which terminals do i read it off? B+ and there is a choice of 3 terminals all close together!

Cheers Leigh

Don't bother trying to get a reading off the alternator. You already know the alt is dead.
Get it rebuilt or replace it.
Good time to upgrade to EF Ford alt...

Jas.

[nicbeer]

did u say it had been recon already?

what revs are u trying this at also.

[FC3892]

i was round the other day, we put some leeds form my car to his, fired it up... tested the voltage from neg to the back of the alt... not a thing. he has had it rebuilt... i haven't been back to see but i think it's got a wiring issue befor the battery. As soon as i pulled the leed off it died

Adam

[RockHopper]

If the charge light isn't coming on when you turn the ignition on, the alternator will not charge the battery while the engine is running as it relies on the load of the charge light to excite the alternator diodes and thus get it charging. If the alternator is not charging at the battery, it does'nt mean the alternator is stuffed. This is why you check it at the back of the alternator. Positive of the multimeter on the B+ terminal, and negative of the multimeter to a good earth. If you are getting good charge there check your wiring and your fuses.

[-Leigh-]

If the charge light isn't coming on when you turn the ignition on, the alternator will not charge the battery while the engine is running as it relies on the load of the charge light to excite the alternator diodes and thus get it charging. If the alternator is not charging at the battery, it does'nt mean the alternator is stuffed. This is why you check it at the back of the alternator. Positive of the multimeter on the B+ terminal, and negative of the multimeter to a good earth. If you are getting good charge there check your wiring and your fuses.

Cheers Guys I will check all that when I get home! Hopefully the problem isn't anything to big!

Will report back soon!

Thanks

Leigh

[-Leigh-]

Ok I did as rockhopper said and checked with the multimeter, positive to B+ and negative to earth......... and nothing! So looked at my dash and found that the battery light doesn't come on when the car is switched to ignition! So because the light isn't on, my alternator isn't getting excited and therefore producing no charge at all!

So must be in the wiring then maybe?

[RockHopper]

Ok I did as rockhopper said and checked with the multimeter, positive to B+ and negative to earth......... and nothing! So looked at my dash and found that the battery light doesn't come on when the car is switched to ignition! So because the light isn't on, my alternator isn't getting excited and therefore producing no charge at all!

So must be in the wiring then maybe?

Start with checking your fuses first. This would be the most common problem. If they are alright remove the green plug on the back of the alternator and connect a jumper wire in the terminal that has the white wire with the red trace and connect the other end to an earth. With the igniton switch on so the reds are on, if the battery light comes on it means you have a problem with the inbuilt regulator in the alternator, and in short means its time to change alternators. If the light does'nt come on, check your wiring and even the globe in the dash and make sure it isn't blown.