What's between the +ve battery and Starter?

[Ross]

So in my latest saga with the car, I've run a long jumper cable from the positive on the battery to the starter directly - last time I used a separate battery - with the intention of proving the battery and the earth.

Car cranks fine, so it is definitely a problem with the 12V feed from the battery, it shows 12V at the starter and when you crank it goes to 0V. So there's something introducing alot of resistance there.

Any info on what lies between the starter 12V feed and the battery terminal? Where does it go? Any fuses, relays, switches, etc etc that I can check? I would have assumed with 100 odd amps it was just direct - clearly not...

Thanks - so close to having her running, it's killing me...

[Error404]

it is on the coupe - big *** cable straight from the battery to the starter

[terrybullwon]

Is there not a big 70amp in line fuse from the battery in the rear to the starter?

[Error404]

not AFAIK, well not on the ABY coupe starter cable I used anyway

[s2_wot]

Ross a few ideas off the top of my head; could you have an unhappy immo with the car having been parked up for a while. Could the factory immo need to be reset by locking / unlocking the car?

I think I said it on another thread about the alternator wiring. I know from my own experience with a VAG TDI that it would not allow the starter to turn if there was a wire wrong. In my case it was a poor connection on one of the small wires.

Could it be a fault in the ignition switch. Afaik the switch is supposed to kill power to a host of other stuff while turning the starter motor. Some sort of a fault there. I'm not sure how you could check this but it would have given some warning signals like erratic wipers, loss of headlights, radio acting up, problems with the indicators.

Hth and you get to fire up the beast soon

[Ross]

First thing first, I'm dropping the starter connection off and proving that connection - it's the only connection I've not 'proven' by passing the starter current through it. If it is a direct wire, then either it's damaged or it's that connection, nothing else to rule out. From Paul's help (thanks) the immob affects the starter solenoid power, not the huge 12V feed itself, and if it was ignition it would start with the "alternate" direct feed.

It has to be the spade connection... gonna get a good connection there today and see what happens.

[martinws]

Have you got the starter solenoid feed separate as well?

[S2central.net]

Ignition switch is easy tested... Simply see you get 12v on solenoid wire when key at crank position.

My memory is that fat 12v wire to starter is daisychained via the alternator. Just make sure it is coming from the correct ALT terminal and not the 'C' pin where the blue wire eyelet connects.

[newsh]

I just looked on the avant and there's no daisy chain at the alternator. Its possible there's a join somewhere with a T off to the fusebox or alternator, (there is on the ur, hidden underneath the carpet..) If not then it must be the spade at the starter motor or the bolt not tight. On the ur I once had the bolt come loose then because of the heat it welded itself in position, the nut felt tight with a spanner but the eyelet still moved.
When you ran the jump lead how did you connect it to the starter?

[Ross]

Thanks for the comments...

I've had a look at the alternator, the connections on the loom come down the other side of the car and are of a much smaller gauge so I don't think it's daisy chained. Interestingly, the nut on the starter looks like it's painted black - not sure where that came from - last time I checked paint wasn't a very good conductor of electricity. John, I clipped a jumper onto the thread of the bolt, so that spade connection has NOT been proven.

Getting closer, if I have to lift the carpet to follow that cable along then so be it, I want to get to the bottom of this now I know where the break in the chain is I'm in for the F1 qualifying in HD, then I'm out to get back under the car. Will report back later

[Jonnybravo]

The avant battery loom is one piece, no fuses

I believe the starter has plastic covers over the nuts, the alternator certainly does

[Ross]

Sorted... took the nut off the starter +ve feed, both it and the spade were very corroded. I took some P800 and contact cleaner to it, put it back and cranked, and she fired up instantly

Sequel thread coming soon... "why does the car idle at 600rpm and sound like the exhaust is blowing at the backbox, but some throttle and 2,000rpm and she sounds sweet as a nut?"

Feels damn good though. Also took my bumper grills and bonnet grill out, treated them with a wire brush and POR15 Metal Ready, and a couple of coats of primer. It's not a great finish - will be temporary - but will look much better than the current 'rust brown'...

[pixsaudisex2]

Good to see you have a happy ending.

[newsh]

Nice one