S3 Won't Turn Over- With History!

[nathpeach]

Hi guys- I really need some help with diagnosing the problem here- it's a long story- my car had been sat for about a year, having had an engine rebuild due to a metal washer in the sump jamming the oil pump- the turbo refurbished and all pig back together the car started just fine, I'd charged up the battery the week before. Once running I got the car mot'd and wax told I needed a new battery- when driving home the car cut out completely- I figured it was probably the alternator. Sure enough the alternator is not charging the battery. However today I went for a short trip (5miles) on the freshly charged battery thinking it would be fine. But when in town, after filling up, the car started ok but sounded like not much power was getting to the starter as it seemed slow- I drove round the corner to stopped and when I tried to start again the starter tried to turn but then have nothing. I assumed the battery had drained although the battery light didn't come on, anyway I hitched home, picked up a battery from a work van. And went back to get the car- put the good battery in and the starter did the same thing/ tried to turn, then gave nothing. Now it won't even click, no sound when turning the key. The car jumped fine and drove home with no problems but when turned off then on again- nothing!

I've ordered a new battery, and got a second hand alt coming- but don't understand why all this electrical stuff keeps giving up- the car rsn fine before it sat for a while

Could it be a knackered starter? How would I tell? Could it be that mice have had a go at the wiring? Could I have blown a fuse? Any help really appreciated! This car had been a nightmare!!

 

[Lewis583]

So you know the alternator isn't charging the battery yet drove it anyway. Really? How do you know the "work van" battery is ok?

With a good battery fitted (just for testing the starter).
Check for voltage at the main starter positive terminal. Should have system voltage (I.e. 12 - 13v)
Next disconnect the starter motor solenoid activation wire (one wire with a black plastic connector on) and check for voltage when the key is held in the START position. You should have system voltage.
Check the engine to chassis earth cable at both engine side (Bolted to one of the bell housing bolts) and chassis side (on the Pass. side chassis leg). Make sure all contacts are clean and tight.

Don't fit a starter until you have at least done the above checks.

 

[nathpeach]

So I've been digging around looking for the problem - found that the earth strap between the starters solenoid and the starter motor has corroded and broken- I assume this is the fault with the starter but could it also be the reason the alternator isn't charging? Is it all linked like that or am I looking at 2 problems? FYI when I checked the alternator the other day I was getting 12.2v from the battery with engine off, and 11.6 with the engine running- hence my assumption that alt was dead (garage also told me it wasn't charging the battery) could the earth fault on the starter be causing this too?

Here's a pic of the strap