Battery Light Off On Ignition, Flickers On When Low Revs.

[notamondayfan 44]

Just a couple of things that I hope someone can help with.

 

First, the battery light is off when the ignition is on....

 

https://www.dropbox.com/s/z7jkf0218hqtud7/IMAG0641.jpg

 

The car starts fine, but on tickover the battery light dimmly flickers on. When the revs rise the battery light goes out. Are these symptoms commoñ with a dodgy alternator, or should I be checking elsewhere first?

 

The other thing Im unsure of is the cables I have connected to the alternator, low pressure switch and oil pressure....

 

https://www.dropbox.com/s/ygk6p6210dmjg2t/IMAG0637.jpg

 

I'm pretty sure they are correct but can anyone confirm please?

 

Finally, the oil pressure sender I have seems a bit tricky to undo. As far as I know there should be a nut behind sender so I could get a spanner in there, but I can't see or feel one. Last time I had it loose was when the engine was out of the car....

 

https://www.dropbox.com/s/1hx8p8ae6nxyhru/IMAG0627.jpg

 

It's impossible to get grips or mole grips in there too.

 

 

Any help would be really appreciated as always.

 

Thanks,

Dean

[S@m 156]

The oil pressure sensor requires a 17mm (stubby) spanner to undo, there are some flats there for the job but its always a bit of a struggle.

 

To check the cables connected to the oil pressure sensor/light just earth them to the block. For example, when you earth the oil pressure sensor wire to the block the gauge will go to maximum, the oil pressure light switch wire will illuminate the stop light when earthed and by the process of elimination you can tell the remaining wire is the alternator exciter.

Can't help with regards to the possibly dodgy alternator but i'd make sure the wires are on the right way round first.

[notamondayfan 44]

OK cheers Sam, I'll see what happens when I get a moment.

 

Thanks,

Dean

[notamondayfan 44]

Thanks Sam I now have the wires the right way round.

 

Do you know of a similar test for the low fuel warning light? The gauge appears to work, but the low fuel light has stopped working.

 

Also the battery light is still playing up. If I run the car, some times the battery light will come on with the ignition, but other times it doesn't. It also still flickers on at low revs, so I put a multimeter on the battery when running and it only shows 12v. I'm tempted to just try an alternator, but is there any way to check if the alternator is working, of if its faulty wiring?

 

Thanks for your help so far!

[S@m 156]

I've found this link to be helpful for alternator diagnosis/testing in the past;

 

http://www.prestolite.com/pgs_training/training_3.php

 

12v when running does seem low, should be more like 13.5-14.5v.

My first port of call before writing off the alternator would be checking the main power loom connections from battery>starter>alternator are clean and secure (my alternator one was loose in the past which led to a faint/flickering light), then check the main earth strap from battery negative>gearbox>chassis and then finally the alternator exciter wire (wire 7A iirc), especially the spade terminal on the alternator itself and where it goes through the brown plugs above the gearbox and on to the other brown plugs under the dash.

 

I'm afraid i can't help with the fuel light - never had to deal with it.

[notamondayfan 44]

Cheers Sam, I have cleaned and checked the connections and everything seems OK there. I will run the multimeter on the alternator itself and see what I get, thanks for the link.

 

I'm not too worried about the fuel light, the gauge works fine. Perhaps the bulb has gone.

 

Cheers,

Dean

[andy1966 3]

hi i had this problem it turned out to be the alternator i checked it with a multimeter and got 12 volts and when i revved it still got 12 volts it should have been been around 13volts i put all the the lights on and the heater on full too and the voltage dropped to 9 volts with the car running in the haynes manual it says it should stay around 12 volts if the alternator is working properly i changed it and it all works fine now

the other thing i noticed was with the car running there seemed to be a a funny sort of noise coming from around the engine where the alternator was i took off the alternator drive belt and fired up the car and the noise had gone it was definatly something wrong with the alternator

replaced it and alls good now working fine

[welshpug 1,666]

so back up to 14v now then?

[notamondayfan 44]

Cheers Andy, alternator will be swapped when I get a spare hour or so. I also check the voltage at the alternator, and it was 12v when not started, and still 12v when running, so I think that confirms it too.

 

Cheers,

Dean