Alternator???
 

:confused: Hi all,

this is a carryover from my engine thread so apologise all round.

Just to refresh, my battery charging light didn't work, consequently my alternator wasn't charging!!

Spent hours today with the electrickery and still no further on, I have got the charging lamp to illuminate by taking a switched live to the lamp.

I did get the alternator to charge by supplying the relay with a different supply, however when I switched on the ignition the alt light went out??? Then when i started the engine the fuse blew for the relay??

Am i missing something here?? Not fully conversant with car electrics so any help would be appreciated.

In the end I had to walk away and put everything in my hands down before i caused some damage:mad:

Hopefully sort it soon though.

check everything is ok with the alternator by simply putting a bulb in-line between +12V on the battery and the charge output post on the alternator

TT

I had exactly the same problem with mine, I found it was teh bulb holder not making proper contact with the printed circuit of the instrument panel. I cleaned it up and put a dab of solder on to the pads where the contacts of the bulb go and it now works perfectly.
hope that helps,
Enoch

Thanks for the replies,

I'm pretty sure its not the bulb, no printed circuit board to deal with.

I'll try the lamp in line, I think its wired wrongly but I'll keep going till something happens!

just to clarify,

large red to battery, one wire to warning lamp fed by 12v switched supply and other one fed from alternative 12v supply?

????

Which engine is this from? I know CVH's have 3 terminals.

the two fat red ones go direct to the battery +12V
the small blue one is the charge lamp.

Rule out all other elements of the charge lamp circuit by removing it and replacing it with an inline lamp back to +12V on battery as described.

We can work from there once we have confirmed the alternator is working.

TT

Cheers TT,

its 1.8CVH, it did charge briefly so it does work, it just kept blowing fuses.

I've only got one going directly back to the battery, one to the chrging lamp and the other goes via relay - this where I think the problem lies but if that one can go straight to the battery then that should sort it - hopefully.

However, when in that brief moment it was charging, the engine wouldn't stop (it was mentioned I'd need something inline to stop this).

I won't be able to tweak today as we are entertaining but I'll have a look tomorrow and let you know how I get on.

Hi,

well managed to get in the garage and have a look.

3 terminals on alternator. (1)Large red to battery. (2)Middle terminal goes to warning lamp. (3)Last terminal goes to relay?

Have have put a bulb between 2 and battery - lamp illuminates. Same with 3.

Connected 3 directly to battery and wired up 2 with a power supply.

Position 0 & 1 on ign and lamp illuminates, position 2 and the lamp goes out.

Position 3, engine starts and alt kicking out 13.5+ volts.

When eng stops, battery warning lamp back on, even with key removed.

Getting there, slowly. Smaller cable to battery seemed to get warm???

is the lamp connected to the black and yellow wire on the ignition switch?

TT

No, at the minute it is just connected to another switched supply.

take a look here http://www.locost.co.za/forum/viewtopic.php?f=6&t=1729

and this is my preferred alternator light arrangement


When O posted this on the Sarf Effirken forum I was asked what the diode was for. This was my response:
I cribbed the circuit off a VW Instrument cluster. I was in a hurry and not overly interested in why it worked only that it did in fact work. It was for use on a drilling rig going into deepest darkest Africa, so all that mattered was that it worked well AND reliably. In the years I was with VW and Audi we never had a charge light failure that was related to anything on the circuitry on the cluster. In my eyes that's a pretty reliable circuit. Several years later now and I've had no comeback from those drill rigs.

Now as to some quick thoughts as to why we have a diode in the circuit.
1.The W or D+ terminal does put out a voltage when charging, so I think the diode is simply a blocking diode to prevent a backfeed.
2.LED's don't like reverse voltage. Reverse voltages as low as 5volts can cause them to self destruct.
3.It may not even have been related directly to the charge circuit.

Component values:
The 1n4007 can be almost any diode rated around 1 Amp.
The 820 Ohm resistor could be any quarter watt or bigger resistor between 680 and 1200 Ohms, it only prevents the LED from self destructing.
The 100 Ohm resistor could be anything from about 90 to 120 Ohms and at LEAST 5 watts (10 or 15 would be better), any lower on the wattage and heat becomes a HUGE issue. I have measured lower wattage resistors getting over 200 degree's Celcius.

Feel free to post any other questions, we all benefit from them.

Cheers fellas for the help,

all sorted (hopefully).

Just ditched the blue & white wire (feeds choke apparently)??

Charges, light goes out and nothing gets unusally warm.

Even stops without a resistor? Bonus.

Bring on the next electrical snag!!!

Hi Daz,

i,m now puzzled....( doesn,t take much :o )

I,m running the cvh with standard carb etc........... the blue /white wire from my alternator doesn,t go to the auto choke, it appears to go to the instrument cluster :confused: :confused:

I know you are not using the original carb so it maybe irrelevant but why would a wire go from the alternator ( major electrickery supplier ) to a mere auto choke system?

cheers
andy

Andy,

Looking at the wiring diagrams, the blue wire from the alternator goes to the dash warning light.

The blue/white wire goes via engine management D to the autochoke. The reason for this I think is that the choke is powered directly from the alternator, only when the engine is running.

If it was powered directly from an ignition switched supply you could warm the bi-metallic spring in the choke without the engine running, which would then partly turn the choke off. Not ideal in real cold start up conditions.

Cheers

Dave

Pinto 1800's feed the auto choke from the alternator,
CVH 1800's do it another way that I can't remember..

TT

TT,

Looking in my Haynes manual section 13.55, diagram 1a. Ignition system 1990 onwards covers 1.6 OHC, 2.0 DOHC, & 1.8 CVH. All connect autochoke to alternator via blue/white wire. Only difference is that on cvh it goes through an relay.

This disgram seemed to stack up when I did the wiring on gus's car.
Might not be the same for all Sierra's though?!!

Cheers

Gus

yeah, I think there's a thermo switch on the CVH that controls the relay, the pinto just keept heating the Bimetalic strip all the time from memory.

It's a very long time since I looked seem to remember Pinto 1800's have an extra terminal on the Alternator that's not normaly found on other alternators.

TT

Thanks Dave?Gus & TT....

The reason I,ve asked is that I have a wire that isn,t connected at the moment ( not sure where it goes :o ) that is coming from what I believe is the auto choke thingy me bob:D

A silly question maybe............... do I need the auto choke?
The car starts first time every time:) even tho this wire is not connected:confused:

cheers
andy

Andy,

This time of year I expect you will get away without it connected. In the cold of winter I would think you would need it. If you know where the wire is you could always connect it up later if you get problems.

Cheers

Dave

Thanks Dave,

I,m going to tie it up out of the way for now :o :D

"save it for a rainy day":D :D

cheers
andy

I'm glad someone else answered that,

I was just going with the easy option no questions asked!!!

But it's working so that will do me:)

The car will start fine even at -10c with the wire disconnected. The purpose of it wire is to heat the bi-metalic spring in the choke control housing. It starts to bring the choke off before the temperature of the water circulating in the auto choke housing warms the spring. So without it you will have a longer period with the choke fully on and the fast idle.

TT

as tt says
im pritty sure its powerd from a relay switched by an ouput on the hybrid ign module with cvh carbed engines

the alternator works by being excited from the small terminal (warning light) this should be connected from a switched supply (usually ignition) so one end is live from the switch into the warning light and then to the alternator.The other large teminals on the alternator go directly to the battery, the alternator is earthed through the engine itself to the earth strap to the battery. Check your earth conection and correct the wiring it will work, if all is ok with the altenator.Hope this helps!