Knuckles

Does anyone know why, other than brushes are gone, that the warning light in an OKA for the Alternator aka battery would come on? I'm just looking for any common OKA faults here. Fuse? Melted wire from too much current draw? bad connection in the wiring?

Back ground/Symptom's - Driving 8 hr yesterday, with head lights on, 150watt inverter running, standard 2 OKA batteries plus extra rear battery on charge (not sure how that's wired into the system but does charge when driving), right hand battery 11.9v, left hand 12.6v rear 13v (also charged from 80watt solar panel), aircon running. When I Ideled back at the first set of traffic lights and stoped near home the warning light and alternator light came on. Would not go out after that tried restarting after a while at home. Tried again tonight still the same.

My first port of call will be check for a fuse, followed by connectivity in the alternator wiring and then finally running the engine with measuring gear on the output of the alternator or bench test.

I had thought about pulling the alternator and starter motor out in the next few months anyway to get new bushes/bearings and brushes put in before our big trip in June up north.

Comments/Suggestions greatly appreciated.

Regards
Kav

First thing to do is check output of the alternator. It should be 13.5 to 14 volts or there abouts. Then start to look at other things. Others may have better ideas.

The alternator does need to be excited. So that circuit needs to be checked as well.

Not sure what alternator you have , but would upgrade to 80 or 120 amp for a trip.

Same thing happened to me coming back from a long trip at night. If I turned the lights off it was night time the Alternator light went off. Replaced the brushes when I got back to Perth no problems since.

Cheers

11.9v, left hand 12.6v rear 13v

Assuming the engine was running when these readings were taken,none of these batteries are properly on charge. If the engine was off and the described loads were still switched on then it is hard to judge - although even then the 11.9 figure is too low.

Thanks, will check and let you know. The readings were taken after I turned off the loads when I got home. I will do a final check on voltages with a multimeter, the above readings were taken of dash gauges not sure how accurate they are. The 11.9 voltage was about 11.5 until I turned off the loads off I kept my eye on it as it was a concern and I was worried about it cutting out the fuel solenoid.

Kav, if the alternator warning light comes on, the alternator has stopped charging. Check that the wire from the dashboard warning light to the D+ terminal on alternator is in place. If it's a permanent fault, check for a short from the warning light to ground in the wiring loom along the chassis (we had that problem).

If tracing the wire is difficult, run a separate wire from the light on the dashboard to the D+ connection on the alternator. Even quicker is to temporarily connect a 5 watt side light globe from the battery +ve to the alternator D+. If/when the alternator fires up, the light should go out.

Also check the belt is tight. Electrical failures of alternators are quite rare, they're pretty tough, possible regulator problem (Bosch regs are quite cheap) but mechanical problems are usually a rear bush/bearing problem.

If it only happens when the alternator is hot I would suspect the brushes. If you have a standard regulator, it's a good idea to change that at the same, they are only around $35-40.

Did you notice during all this if the tacho was working ? The same D+ (pulse) output from the alternator that illuminates the alt/batt light also drives the tacho. It also provides the voltage to activate the battery coupling solenoid.

The OKA dash voltmeter is notoriously inaccurate and should only be used in a comparative manner. A multimeter is a better bet. Could be that you've got a crook diode in the alternator resulting in partial output.

Deano

The OKA Dash volt meter is in accurate because it gets its supply from the back of the alternator, not the batteries.

I have changed the main feed from the Alternator to the 2nd battery. now my lights dont dim, my volt gauge is more accurate etc.

No the Taco was not working, that was my first indication that there was a problem before i saw the red light.

Kav
I have had this happen.
Check the wires coming out of the the small plug that clips to the back of the alternator. This is fairly close to the turbo dump pipe, the heat causes the insulation to harden and crack and eventually the copper gives it in too. This may not be obvious with a casual inspection and the break may be very close to the plug

Hi Shane
As David and Dean indicated, alternator may not be spinning (fast enough), due to belt slipping. Might not be obvious as there may not be a screeching noise.
I had the same, it only happened when straight after starting the engine or when I had switched on all the lights and/or (12 Volt) fridge. Replaced belt, no further problems.
After replacing the belt noticed something else: the tacho showed approx. 200 less RPM. When I measured the old belt it was 1.5 mm narrower (due to wear?)compared with the new one, and therefore it run closer into the groove, spinning the alternator faster (when it was not slipping) and showed higher revs.
BTW the belt part numbers were identical.

I havent got any pictures, but I put a heat shield on the exhaust to protect the alternator and A/C.

I used a flat piece bolted to the three bolts on the horshoe shaped exhaust pipe coming off the turbo. When I got 169 the exhaust was leaking near the Turbo, where they all seem to leak at times. I did replace the seal, but it leaked again. I put putty on it to slow it down a little. Due to hot, dirty smoke getting onto the alternator it cooked it. I am hoping I will not have worry about it in the futures

Pictures below are the same stuff I used.

Dean and Kaye Howells wrote: ........................................... The same D+ (pulse) output from the alternator that illuminates the alt/batt light also drives the tacho. .......................................Deano

Don't believe this bloke, he tells porkys !!!

Sorry, a moment of electrical dumbness must have overtaken me. There are three wires on the back of the alternator. The big thick one goes to the battery(s) and is the alternator output. There are two smaller diameter wires, one goes to the alt/battery lamp and is illuminated if the ignition is on and the alternator has no output,(engine not running with ign on, broken fan belt or crook alternator). The other feeeds a 'pulse' from one of the three internal outputs in the alternator and it is these pulses that are counted and used to show engine RPM. The voltage of these pulses also increases with alternator speed and this increase in voltage is used to operate the battery coupling solenoid thus ensuring that the batterys are only coupled when the engine is running (as oposed to the position of the ignition key). On #413 this occurs at approx. 1100 RPM.

Firstly check the drive belt (as Hank points out) and the wires (as Peter mentions). If these seem OK then your alternator has had it. Probably a good time to check with Allan and get one of his alternator upgrade kits so that a replacement common or garden variety alternator can be used instead of the OKA factory one.

Deano

Thanks I've had a look at the belt, while it is a little loose it still spins the alternator ok as I ran the engine with the access up and watched it. Got the revs up but no change.

I've had a look at the wires and what I can see all look ok, they feel snug behind the alternator, but access is limited, not much room eh?

I know the seats are quick release and removable are there more panels that can come out to get access to the alternator?

Regards
Kav

Some pics..also attached...Looks like ive developed a Aircon leak too

Looks like your A/C compressor has done a front seal......

Once the seat is out, you can take a side pane off against the engine tunnel, that will make it a little easier.

I would say you have a 85amp alternator or bigger....

Kav, I assume the a/c is working OK since you said it was on.

In that case you may be lucky as the leak is probably oil, not refrigerant, and is repairable. This is an extract from the Sanden Service Guide (available here ).

New compressors are around $400.

7.4 Leak Checking
7.4.1 Visual Inspection
Although oil seepage does not necessarily indicate leakage of refrigerant, it should be considered a sign that a leak may exist. Look for the following items:
• Oil seepage in shaft seal area (between clutch and compressor) - repairable.
• Pinching or extrusion of front housing O-ring – non-repairable.
• Oil around cylinder head (gaskets, service valves, fittings) - repairable.
• Oil around oil plug - repairable.
• Stripped threads – non-repairable.
• Oil around crack in compressor body – non-repairable.

So I went in tonight and with the side access cover off I could see a wire with only 3 strands left connected to the alternator...looks like that is the cause of my problems



V-Belts were cracked so I will replace them but more importantly there was end play on the shaft of the alternator. A spin revealed a slight noise which is probably the noise I thought I could hear when I was driving, but wasn't sure... Anyway Covs at Rockingham had an 85A alternator on the shelf today for $215 so I grabbed it encase I would need it and im glad I did. I will rebuild the old one and keep as a spare. I have also asked Allan at OKA parts for a price on an upgrade kit for later on.



I had to take the top radiator hose off and am now wondering if a I had a leak of coolant on the trip back last weekend and this might be the green colour I can see on the air con compressor, and the air con compressor might be ok. I will clean it all up and go for a run this weekend with out running the air con and see if the same thing happens or not. if not try running the air con and see if it comes back.

Regards
Kav

Kav,

Looks like it has been sitting on the exhaust, another reason I put the plate between exhaust and alternator.

It looks like your orginal Alternator was a 85 AMP one, hard for me to see. It should bolt in.

Here is my 120 Amp alternator, previously it was 55 Amp. I needed a new mounting bracket.



I have since mounted the insutalor between exhaust and A/C and Alternator.

Also wiring has been cleaned up and both Alternator and A/C realigned

Fixed!!!....Light now goes out and tacho working again. I will make a heat shield and fit it leter, good idea, in the meantime I have fitted split tubing and will tie it back as far away from the manifold as possible

Kav, glad the alternator is now fixed.

While tying up the alternator wiring, do the same with the starter motor cables to keep them away from exhaust heat.

I don't know of any source of radiator water near the a/c compressor (apart from maybe the overflow pipe) and then it would be sprayed all over the place. And sadly a/c compressor leaks are usually green (probably the leak testing dye they put in them)...