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Discussion Starter #1
story first!

so went to start van sat morning & it struggled to start but did fire up,immediate thought was battery is on its way out.
continued journey pulled in to a car park & the EML light came on & the van basically stopped, tried to turn it over & same thing happened very sluggish & wouldnt start.I happened to be across the road from euro car parts so bought a new battery & fitted it,van fired up & on i went no lights on thought i had cured it then yesterday just turning into my road & the EML comes back on just about parked up & switched it off.

today my OPCOM has given a fault code PO560 (system voltage low :input not present)

with engine running i took a reading at the battery terminals of 13.5-13.7v

with engine running the software gave a reading of 11-11.3v only on tick over & 3000rpm

ignition status 12v & holding at that

new battery fitted so could this be the alternator?

thanks in advance.
 

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Could well be.
 

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If the engines running and your only seeing 11v then the alternators not charging, 13.6 to 14.6 is what you should see, check to see if your alternator has a clutch pully, I've had 2 of those pulleys go out on my 1.7 in the past basicly the the engine runs but the alternator clutch can't grip and keep the alternator spinning it gives the illusion that's the Alts failed so take the aux belt and spin it both was it should free wheel anticlockwise and lock clockwise, your know if you have a clutch pulley as there will be a black cap on the front of the pulley, also check the alternator wiring to, I've had mine corroded out where the main live bolts to the alternator.
 

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Discussion Starter #4
If the engines running and your only seeing 11v then the alternators not charging, 13.6 to 14.6 is what you should see, check to see if your alternator has a clutch pully, I've had 2 of those pulleys go out on my 1.7 in the past basicly the the engine runs but the alternator clutch can't grip and keep the alternator spinning it gives the illusion that's the Alts failed so take the aux belt and spin it both was it should free wheel anticlockwise and lock clockwise, your know if you have a clutch pulley as there will be a black cap on the front of the pulley, also check the alternator wiring to, I've had mine corroded out where the main live bolts to the alternator.
yes the onscreen voltage of the opcom was only 11v but a reading at the battery terminals was 13.5 to 13.7 with engine running.

i cleaned up the battery terminals & cleared the fault code then went for a drive & watched the voltage on my computer & as soon as the EML came back on the voltage dropped further & power drops basically crawling back.

I cleaned up the bolted wire on the alternator then got rained off,im not sure if the alternator has a clutch but it has got an oil leak,i had it off before to try & seal it where the vac pump is connected it worked for a while but the leak came back so maybe its finally had it.

thanks for your reply by the way
 

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If you look at the alternator from underneath, you will see a small drain hole near where the vacuum pump bolts on.
If oil is leaking from the hole, then the oil seal on the shaft is leaking, and oil might be getting on the brushes/slip rings.
To fit a new seal, you have to strip the alternator down (not too bad if you take your time).
 

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Discussion Starter #6
If you look at the alternator from underneath, you will see a small drain hole near where the vacuum pump bolts on.
If oil is leaking from the hole, then the oil seal on the shaft is leaking, and oil might be getting on the brushes/slip rings.
To fit a new seal, you have to strip the alternator down (not too bad if you take your time).
Hi alan i tried a new seal between vac pump & the unit & it lasted a while but the oil leak came back.in the summer i took a few items off a scrapped van one being an alternator as i had thoughts of mine packing up.obviously I dont know if the unit will be any good but it is oil free around the pump & being a gambler it might be worth trying it,i am going to check all wiring first though just in case its a simple fix but the voltage is really dropping out some where
 

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Hi alan i tried a new seal between vac pump & the unit & it lasted a while but the oil leak came back.
If you replaced the "O" ring between the vacuum pump & alternator, that is not the seal I'm talking about.
The oil seal that has gone previously on my alternator is inside the main body of the alternator, and can only be changed by stripping it down.
Number 7X in this picture:
If you have another alternator that looks dry, then try it.
 
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Discussion Starter #8
If you replaced the "O" ring between the vacuum pump & alternator, that is not the seal I'm talking about.
The oil seal that has gone previously on my alternator is inside the main body of the alternator, and can only be changed by stripping it down.
Number 7X in this picture:
If you have another alternator that looks dry, then try it.
Ok with you, i can look at that once it becomes a spare

i had the plug off the alt today some of the wire was looking tired so i cut that away & tried another plug all so cleaned up the main power cable to it,cleaned up all battery connections & earth to the body & fitted a reverse light switch under the tray.

put a bit of juice into the battery & fired it up opcom showed 13.5v tried it under load with the blower on full headlights etc & it held thought i had cracked it but as the minutes passed the voltage started dropping out it reached 12v before i shut everything off.

i might give the alt a quick blast with some electrical cleaner see if that helps the spare alt i have was taken off a 1.7dti looks the same but i think i need to check its amp output?
 

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Don't get too wound up about the amp output, as it came off another diesel it should be fine.
 

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Discussion Starter #11
fitted alternator today but no luck not charging battery light stays on thats two that are duds unless some thing else is to blame, but original one was soaked in oil & the spare was taken off a scrapper so....
 

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Discussion Starter #12
does anyone know what voltage i should have at the alternator 2 pin plug because i have only recorded about 2 volts

main power cable from battery has the same voltage

just trying to rule anything out before taking the alternator off again!
 

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Main power cable has 2V as well or has the same voltage as the battery?
 

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The one wire at the two pin plug picks up the voltage after the power has gone through the warning light, so it won't be very high (unless things have changed since I did my training on alternators back in the 1970's).
The last alternator I rebuilt recently was an Astra one like yours, and I tested it by holding it in a vice, connecting the main wire to a battery + with a jump lead, and the body of the alternator to the battery - with the other jump lead.
I connected (I think it was the blue wire) to the positive via a 5 watt bulb (to simulate the warning light), then spun the alternator with an electric drill and confirmed it was working by checking my warning light went out, the battery voltage increased to about 14 volts, and used a clip on ammeter to look at the amps being produced.
Oh, and do this before you fit the vacuum pump on the alternator to avoid damaging it by running it dry.
It sounds complicated, but I thought it was easier than fitting the alternator on the car & finding it wasn't charging!
 

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......The one wire at the two pin plug
Oh, and do this before you fit the vacuum pump on the alternator to avoid damaging it by running it dry.......
It also stops you spraying residual oil all over the place from the pump.
 

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Discussion Starter #17
The one wire at the two pin plug picks up the voltage after the power has gone through the warning light, so it won't be very high (unless things have changed since I did my training on alternators back in the 1970's).
The last alternator I rebuilt recently was an Astra one like yours, and I tested it by holding it in a vice, connecting the main wire to a battery + with a jump lead, and the body of the alternator to the battery - with the other jump lead.
I connected (I think it was the blue wire) to the positive via a 5 watt bulb (to simulate the warning light), then spun the alternator with an electric drill and confirmed it was working by checking my warning light went out, the battery voltage increased to about 14 volts, and used a clip on ammeter to look at the amps being produced.
Oh, and do this before you fit the vacuum pump on the alternator to avoid damaging it by running it dry.
It sounds complicated, but I thought it was easier than fitting the alternator on the car & finding it wasn't charging!
Ok thanks just trying to figure out what voltage should be on that plug but from what you say it may be normal to be low
 

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Are you sure your looking in the right place, i always thought this code referred to the system voltage not battery, so you should be looking at the engine sensor voltage not the battery/charging system, whats your engine code so i can look at the wiring diagram.
 

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Discussion Starter #19
hi engine code is z17dtl fault code PO560 (system voltage low :input not present) when battery dips to a low level this flashes up,if battery has a good charge then its light stays on at the dash.the alternator or something is stopping it from charging,the battery slowly loses voltage the engine coughs & the code is stored. this is all i know & the thinking is that the alternator was dead,changed it for another same problem again but it was a spare off a scrapped van.

thanks
 
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