voltage and charge issues on y60

[kiwijase]

hiya guys.
im havin probs with my wagon..
I noticed my voltmeter dropping on the way for a fish yesterday and thought id leave it running while feeding the fish in hope it would charge a little,but it dropped right off to 12v on the guage,my horn wouldnt even work.So i shot off and while going over a bit of a jump,i saw the guage go right up to 24-26v and then drop off to 12 again.............mmmmmmmmmmmm/Could it be an earth prob?
Ive also noticed lately (2wks or so)my glow light only stays on for a second at the most,and even less when the key is turned off and back on,and she can be a little hard to start in the mornings,the rest of the day its allgood.I did have a voltmeter,but las you do,i lent it out and its never been returned.
Any ideas you guys have would be good to hear.
Cheers

[my third 256]

are the terminals to the battery tight and clean might br that

[Yendor]

Yes, check the connections at the batteries, the main earths to the engine and body and the connections at the back of the alternator.

Does the vehicle still start now? have you noticed your lights brightness changing?

Without a voltmeter it is a bit hard to test.

It could be a faulty dash gauge, alternator or vehicle wiring faulty.

Does the battery/alternator warning light in the dash work correctly?

With the hard starting you will need to check your glow plug circuit. First make sure the busbar that links the glow plugs gets power, then make sure each glow plug has continuity.

Have you swamped the vehicle recently? had water inside the cab?

A multimeter will be very helpful in diagnosing these problems.

[megatexture]

try giveing the alternator a drowning with innox/wd40, works wonders for mine i even do it while its running and had no problems.
sounds like what happens to mine i need to strip it down and give it a good clean its just grime/dirt possibly worn brushes?

[kiwijase]

the terminals are lead,and look to be shit. it has the diesel filter(dripping cannister looking lite),batt and trans temp lite on when its running and charging low on the volt meter,but when i increase the revs the lights (dash lites mentioned)will dimm,but will liven up again when the revs drop./Im really hoping its not the alt,but as mentioned,its a bit hard without a multimeter,so ill get one next week when im in the closest town next and get back to you guys.
thanks guys

[kiwijase]

ok,ive cleaned all the battery terminals,removed and cleaned every earth strap i could see (the one going to the intake ha d a slightly stripped thread ),checked wiring behind gauge cluster and radio panel and have charded both batteries,aswell as checkign plugs on the alt.
tomorrow ill put the batteries in and see what happens,if no go ill get a meter and go from there..........thanks guys

[megatexture]

flush the alternator with water and wd40/innox it up also

[the evil twin]

the terminals are lead,and look to be shit. it has the diesel filter(dripping cannister looking lite),batt and trans temp lite on when its running and charging low on the volt meter,but when i increase the revs the lights (dash lites mentioned)will dimm,but will liven up again when the revs drop./Im really hoping its not the alt,but as mentioned,its a bit hard without a multimeter,so ill get one next week when im in the closest town next and get back to you guys.
thanks guys

99% You've either dropped an output phase (blown diode/s) or the excitation from the battery via the brushes is open cct and the slight rise in the output (warning lights dimming but still on) is due to the residual magnetism in the rotor giving you a very small output.

If it is sticky brushes what has already been said by others may get it going. If so I would still pull it down/get it serviced as soon as possible

[kiwijase]

righty...........
i biffed everything back together and started it,started sweet after the usual on and off of the ignition 4-5 times,the glows only stay on for half a second each time.
Checked guage,just under 24vlts so i tested the wires on the back of the alt,24 on one and 24.9 and rising on the other wire,went and looked at the dash lights and they had been on,but were now off,and i noticed a slight increase in idle when i was poking round at the back of the alt,so im assuming(jesus i hate that word) that it was a faulty connection or sticky brushes?
But i still dont know why the glows dont stay on as long as they once did.?
Thanks for all your help you guys!!!

[kiwijase]

ok,lites on dash have come back on,still charging at same voltage though?

[kiwijase]

what is trhe output voltage meant to be?
If the alt is poked,is it easy enough to replace the reg or other components?

[Yendor]

With the engine running and at a fast idle, what is the voltage reading across the alternator? (positive probe of multimeter on the large white wire and negative probe scratched into the alternator case).

Next test, motor off, ignition on, disconnect the 2 pin plug from the alternator. Now without damaging the terminals of the plug, back probe the connector. You should see battery voltage, around 24 volts on both wires.

Leave the voltmeter connected to the small White wire in the connector. Now while wiggling the harness up to a foot away from the alternator keep an eye on the meter, does the reading drop down at all?

I would say you have a faulty alternator, could be worn out brushes or a faulty rectifier (unless your fan belt is slipping).

Carry out the above tests and let me know the results.

[kiwijase]

will do,thanks so much Yendor. Im 40kms from the closest towm/village so your helping me is a god send.

[kiwijase]

With the engine running and at a fast idle, what is the voltage reading across the alternator? (positive probe of multimeter on the large white wire and negative probe scratched into the alternator case).


first point...........voltage reads 25.5 vlts here

Next test, motor off, ignition on, disconnect the 2 pin plug from the alternator. Now without damaging the terminals of the plug, back probe the connector. You should see battery voltage, around 24 volts on both wires.

second point:......23.4 vlts on both white and red/white wire


Leave the voltmeter connected to the small White wire in the connector. Now while wiggling the harness up to a foot away from the alternator keep an eye on the meter, does the reading drop down at all?

done that aswell,no change in voltage Yendor.So its safe to assume the rec or brushes are stuffed.
Do i have to replace the bearing and oil seal if i pull it down to check the brushes?

Thanks so much for your help.

I would say you have a faulty alternator, could be worn out brushes or a faulty rectifier (unless your fan belt is slipping).

Carry out the above tests and let me know the results.

...........................

[kiwijase]

forgot to mention,i read in the manual that the rear bearing and oil seal shouldnt be reused,whats your thoughts there,as silly as that sounds.
Also,are there more than one type of TD42 alt?
And i still cant work out why that lite that looks like a dripping filter is on with the battery and AT temp lite?
Oh,would you know which battery is the starting battery out of the 2,im not sure,id think it was the one with a lead going to the starter,being the lefthand side as you stand facing the front of the engine?
Sorry ffor all the questions,im very keen to fix my trucks probs but learn aswell so I may be able to help others in the future also.
Thanks
jason

[the evil twin]

Hiya Jason

Yours is a 24 Volt system so both the Batteries are the Starter Battery as they are in Series.

Alternator Output still sounds too low to me and the "dripping filter" light is the fuel filter warning is it not? When you get the Alternator side of things sorted you will probably find all three lights will extinguish.

Woudn't you agree Rodney?

[Yendor]

100% ET, I just want to make sure it's not a problem with the battery sense circuit before I fully condemn the alternator.

Jason, As a general rule for an overhaul you would replace the bearings and the oil seal.

[kiwijase]

battery sence circuit,whats that yendor?
Thanks for your help guys. Is it a job i could do myself to save money,as i have bugger all to spend.
Or should it be checked over and done by an auto sparky.Ive done brushes on alts before,but never a rectifier or diodes and such.

[Yendor]

The battery sense circuit is the small white wire in the two pin plug that connects to the alternator.

Brushes are easy to replace and so is the rectifier plate (diodes) if you can get a replacement one.

[kiwijase]

oh ok,so i need the entire plate?
Could i maybe remove the actual diode/s or rectifier,are they a parts i could buy new,or would one from a wreckers be less trouble?

[kiwijase]

bumpage for last question