15 replies to this topic

[Vinay-RS]

So, following on from my last issues with starting, it turns out that the battery was going flat because it wasn't being charged. 

 

I checked the voltage across the battery terminals with the car switched off, I got 12.4V. When I started the car, let it idle for a bit and then pulled the choke out a bit to lift the idle, the voltage dropped to 12.2V instead of increasing to 13.5-14.5V as suggested in the books. 

 

I have read the other posts on this topic on the forum and I'd seen that the charge light is another thing to check for issues. The charge light came on with the key in the ignition and then once the car started, the light went off. 

 

I assumed the issue was that the alternator wasn't delivering enough voltage, and so needed replacing (which is tricky here) or rebuilding. So I proceeded to purchase a new regulator, rectifier and bushes, take apart the back of the alternator, cleaning it up and fit the new components. Now, assuming that I rebuilt it correctly (I have limited faith in my ability), then it should work. Did the same check as above and the result hadn't changed. ~12.4V with the engine off and ~12.2V with the motor running. The charge light comes on when the key is in and goes off when the engine is running. 

 

I was also advised to clean the earth connection in the boot. Which I did first (before messing with the alternator). 

Now, while all of this was happening, i had drained the battery, and I thought, perhaps, the alternator couldn't charge the battery because it had become too flat. So I got a jump start, took the battery to a battery shop to get it charged and then fit a loan battery. This battery worked to start the car but the voltage across the terminals with the car running was still 12.2V. 

 

I checked the engine bay now and I found one of the earth straps is barely attached. If one of the earth straps to the body is loose or not attached, would that prevent the alternator from charging? 

 

I think it's the starter wire (the one in yellow with tonnes of tape on it.). It has a rather rubbish connection and the wire looks to be in horrible condition. The other connections seem solid though.  

 

What should I check next? I'm really worried about what is broken and more worried that the car is going to leave me stranded somewhere. 

 

[nicklouse]

well the "earth" is a self added wire so no idea what it is earthing or trying to earth.

 

and the other is your white/red starting wire.

[Bat]

Hi,

You should have an earth strap going from the engine to the body.

Usually this is on the top engine steady bar.

No or bad earth will cause problems, even alternator damage.

Cheers 

[Vinay-RS]

well the "earth" is a self added wire so no idea what it is earthing or trying to earth.

 

and the other is your white/red starting wire.

I connected that earth wire a little better and sorted out the starter wire with a new connector. Made no difference to the voltage readings across the battery. 

 

Hi,

You should have an earth strap going from the engine to the body.

Usually this is on the top engine steady bar.

No or bad earth will cause problems, even alternator damage.

Cheers 

Thanks. Probably more dodgy wiring on this car. Sigh. 

[nicklouse]

well the "earth" is a self added wire so no idea what it is earthing or trying to earth.
 
and the other is your white/red starting wire.

I connected that earth wire a little better and sorted out the starter wire with a new connector. Made no difference to the voltage readings across the battery.

it would not they are nothing to do with the charging system.

[Vinay-RS]

 

 

well the "earth" is a self added wire so no idea what it is earthing or trying to earth.
 
and the other is your white/red starting wire.

I connected that earth wire a little better and sorted out the starter wire with a new connector. Made no difference to the voltage readings across the battery.

 

it would not they are nothing to do with the charging system.

 

not sure where else to look or what to check next then. 

[Bat]

Hi,

What voltage are you getting on the thick brown wire on the back of the alternator?

Cheers 

[Vinay-RS]

Hi,

What voltage are you getting on the thick brown wire on the back of the alternator?

Cheers 

I checked the voltage across the solenoid from the wire from the alternator, it was 12.3 V, checked the voltage across the alternator too and it was 12.3 V. 

[nicklouse]

sounding more like an alternator issue.

 

you have not changed anything on the dash have you?

[Vinay-RS]

sounding more like an alternator issue.

 

you have not changed anything on the dash have you?

No. Haven't touched the dash or the gauge cluster. I've ordered a new alternator from another city which should hopefully be here tomorrow. I hope it sorts out the issue. 

[gazza82]

Not an LED in the ignition lamp? That won't work!

[Vinay-RS]

Not an LED in the ignition lamp? That won't work!

Definitely not. I haven't changed any of the bulbs in the gauge cluster yet. I had heard that it's a good idea to fit LEDs for backlighting the gauges though. 

[timmy850]

What terminals do you have on the alternator? Separate wires or a plug?

 

If you have a good auto electrician near you some of them have an alternator testing rig they can use to check the output. 

[Vinay-RS]

What terminals do you have on the alternator? Separate wires or a plug?

 

If you have a good auto electrician near you some of them have an alternator testing rig they can use to check the output. 

It's a single plug that fits onto the rectifier. 

 

I bought a new alternator, which I'll fit today afternoon. Hoping it sorts out the issues. 

[Vinay-RS]

So it was the alternator. Replaced it this evening and I'm getting a steady 14V across the battery terminals with the motor running and the revs slightly raised.