So that would prove my Earths are good, I guess I need to check the alternator mounts and connections next. Is the best way from above or below it?
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So that would prove my Earths are good, I guess I need to check the alternator mounts and connections next. Is the best way from above or below it?
~Rich~, you say you had your battery and alternator replaced recently. Was that done on spec to try to fix this problem, or had they actually failed?
I presume you have a D3 - petrol or diesel? How many k's? What year model? Are your 750 k's a week done by daily driving or just weekend driving?
Cheers,
Paul
2005 TDV6 HSE, 134,000 kms, that 750 is my work day week total for 5 days @ 150.
The problem has shown up months after the Alternator replacement and approx 1 yr after the battery was replaced. Both failed seperately.
~Rich~, when it fails to start, is that on a Monday after an idle weekend, or does it happen any old time?Quote:
Originally Posted by ~Rich~
.... and do you have any load regularly connected to the aux battery?
Nope
Hi Rich, and there is a known problem with the V6 D3s where their earth, between the motor and the chassis, breaks it’s bond at the chassis.
It’s not an easy job to fix as you need to take the front right hand wheel off and the wheel arch cover, to get at the chassis earth.
You can either do that and/or fit a new engine to chassis earth.
A little tip Rich and for anybody else, if this is the problem, it not only has the potential of damaging the alternator but it can also damage your starter motor.
So check for voltage difference between the block and the chassis too, again with a load on the alternator.
Hi Graeme and unfortunately NO.Quote:
Originally Posted by Graeme
you need to get a visual of the actual bond situation because the earth return can actually be via a different course all together.
This was a problem many years ago, where the earth cable was frayed or even missing and the earth return was via the starter motor or gear box mounts.
This would lead to the tips of the gear teeth being burnt and damaged and the first time I heard about it I was sure it was a truck load of horse do-do, but after I was told by people who were well aware of the problem that it was fact, and I got an education.
The problem sort of went away with better earth straps being used but this problem is starting to reappear because of the hugh current draw most new vehicles, particularly 4x4s, need just to operate their day to day electronics and such.
So in this case, a visual is needed.
I would still expect to see a small potential difference due to the less than perfect earth path.
I chased a fault with the charging on my RRC and found it because of less than a 0.5V difference with headlights on, caused by an alternator mount bolt not absolutely tight which allowed corrosion to build-up over time.
I diagnosed a 2nd battery charging problem on a D2 (not mine) part of which was caused by the 2nd battery's earth being connected to the chassis instead of the body, where the earth path was via the steering box, steering box bearings, drag link ball joints, suspension ball joints, front tailshaft uni joints and sliding splines and gearbox bearings to the gearbox casing. The potential difference was almost 1V in this case. D2s don't earth the chassis.
A particular make of trucks use an alternator to which an extra earth post has been added by a 3rd-party supplier to overcome problems caused by a poor earth path between the alternator and the block that caused electrolysis in the engines. No amount of inspection would have revealed the poor earth path. BTW, the alternator manufacturer had not been aware until very recently of the fitment of their alternator to this engine nor of its modification.
However, an inspection will reveal any gross faults.