Earth Straps

[Distilled Waters Run Deep]

I've been searching the forum for ages, I still can't find anything to tell me where the engine earth from the battery is. I've cleaned up the connections in the bonnet including the one to the bolt near the glow relay, and the separate strap beneath the engine to the chassis... would someone kind point me in the right direction?

[g8dhe]

[Distilled Waters Run Deep]

Thanks very much Geoff -I must confess that has me as confused as ever, but I'm sure there's a clue there... ah, got it! I think... There is a lot more to these cars than meets the eye...

[g8dhe]

Each of the numbered circles is an earth connection point, the second diagram shows where these earth's are located physically on the chassis. A few other things like the Starter, Alternator and sensors rely on earth connections via the chassis fixing points. In the main diagrams these are represented by solid black circles rather than numbered circles.

The Battery -ve lead also goes to the chassis, just follow it down to the chassis. The engine itself will normally have a direct connection as well, but it will depend on the engine you have, I've never bothered to locate it on the V6 we have

[Northern Bongolow]

I've been searching the forum for ages, I still can't find anything to tell me where the engine earth from the battery is. I've cleaned up the connections in the bonnet including the one to the bolt near the glow relay, and the separate strap beneath the engine to the chassis... would someone kind point me in the right direction?

there isnt one thats why you cannot find it. the battery negative goes to earth/chassis, the engine is earthed via the strap underneath to the chassis so in effect the earth circuit is completed through the chassis back to the neg terminal.

[Distilled Waters Run Deep]

Thanks both. The double lead coming off the negative on the battery made me think that the long one went to the motor somewhere else, but I see from those diagrams that it must branch off wide and far. Those main points all being cleaned, as I said in my question, the alternator failure may be down to me still not having tightened the small back bolts on it. Mind you, I've tried all three of my Bongo alternators on it now... it seems unlikely they all have loose bolts?

[nth]

If you suspect an earthing problem I would just add in additional new (thick) earth leads between engine/chassis/battery. Universal earth leads are cheap as chips.

[cmm303]

If you suspect an earthing problem I would just add in additional new (thick) earth leads between engine/chassis/battery. Universal earth leads are cheap as chips.

You could try eliminating a potential earthing problem using a jump lead to provide a temporary earth.

[Northern Bongolow]

what are the symptoms you are having, how is the alternator failing, is it resulting in an over charge or an undercharge or other.

[Distilled Waters Run Deep]

what are the symptoms you are having, how is the alternator failing, is it resulting in an over charge or an undercharge or other.

Sediment light and battery light stay on, and battery gradually drains. I've THREE alternators, two of them cheapo jobs from China to be fair, but none sort the problem. I must admit to not yet cleaning/retightening the back bolts on the cover, as I've read elsewhere to do.
Otherwise, touch wood, she seems to be fine!

[Northern Bongolow]

it sounds odd that you have tried 3 and they are all duff, have you tested the output on the alternators both ticking over and on part revs to see if they are doing what they should.

is the thin black exciter wire connected on the alternator loom.

[Distilled Waters Run Deep]

Cheers, I'll have time to try this on Sunday

[Northern Bongolow]

ah ive just noticed your edit. the alternator needs to be 90 amps,with the green band around it, the black banded ones are usually only 80 amp copies and dont last that long.

try hooking up another vehicle and jump leads to your bongo, see if that puts the light out when 2 alternators and batteries are are charging the system.

[Distilled Waters Run Deep]

it sounds odd that you have tried 3 and they are all duff, have you tested the output on the alternators both ticking over and on part revs to see if they are doing what they should.

is the thin black exciter wire connected on the alternator loom.

Does that thin wire go to ground? -it's in poor condition...

[Simon Jones]

The thin exciter wire should have a 12v supply to it. If the 12v is missing then it will not charge.