Thank you. I’m assuming that a normal heavy-gauge cable will be adequate here, direct to chassis, rather than the massive 200A type. In other news, it was my works Christmas do last night and the headlights got their first proper test since adding the extra earth. Bloody hell! I would guess...

All seems to be well so far. Lights brighter and wipers slightly livelier. I’m happy the truck as a whole is working well and fit for Christmas visitation duties. Medium term plan is now to buy/make and fit a boomslang loom or equivalent, and to beef up the earths across the vehicle. I’m not...

It's a Gunson Pocketmeter, nothing special. My mistake of course - it's reading in ohms, not milliohms. It's got scales labelled 200 ohm to 20 Mohm (I think) and I am reading on the lowest. I think I got mixed up with millivolts. My previous understanding of resistance was just continuity/no...

I was quite pleased. With the meter set to milliohms, just touching the probes together gives a reading of 0.2 mohm, so I thought that wasn't too bad. Headlights significantly improved - by 50% as a rough estimate. Still yellowy rather than the white of modern headlights, but much better for...

Right, a solution of sorts. I am really pushed for time at the moment, so as a quick and temporary solution I have bought an 18" earth braid from Halfords and fitted it between the chassis point for the earth cable flag (duly cleaned up and copperslipped) and the battery -ve. This is just to...

Yes, I can see how it wouldn’t be too successful. It’s just an idea to confirm beyond doubt that I have found the problem, and to keep the truck driveable until I can order some new earth cables in.

Starting has never been a problem, but the lights are terrible! Since I found the loose connection, I have checked the continuity between battery -ve and a screw on the dash. It started at around 0.2 ohm, but then I wiggled the earth cable and it went up to 150 ohm. Volt drop between the two...

Ok, quick update: the rain has stopped and the ground is drying out. The battery earth strap goes to a point on the chassis where is it held by a P clip, and then goes on to a bolt on the gearbox. The battery and gearbox connections seem tight and uncorroded. However, the cable is slightly loose...

Thanks Dippypud. Looking into it.

Golly - this has been really helpful. Yes, when I said I was looking for zero/some voltage between battery and chassis (etc) I was assuming the ignition was on so there was a voltage to measure. Should have been clearer. I'm at work (and very busy) today and tomorrow, but next week I am going...

Thanks for this. So - if there is perfect continuity between battery/chassis/engine block, a voltmeter between them would read zero. Any voltage (measured in millivolts) would indicate a bad connection. Have I got that right?

That's a very helpful reply, thank you. I'm OK with using a voltmeter for continuity checks and reading raw voltages, but reading voltage differences is new to me, However, what you say makes sense and I will give it a go today. The headlight units are Wipac with clear lenses and a rippled...

I have heard this before. Makes perfect sense. As soon as the driveway isn't under water, I'm on it. This is a new one for me. I'll have a look into that too. The headlights are pretty ineffective, much worse than I remember on my n/a 90. Thanks both.

Alternator is putting out 13.9V at idle, falling to 13.7V with headlights and HRW on. Curious thing is if I increase the revs to a fast idle (2000-ish) the alt output falls slightly to 13.8V no load and 13.6V with lights and HRW on. When I have checked vehicles in the past, the voltage usually...

Hmm. Checked the alternator when I got the truck and it was fine, but haven't looked at it since. How do I check for 'leakage between the battery and frame earth'? Not sure what you mean there. Off outside with the multi-tester. Thanks.

I've had the truck since May but it's only recently I have been driving with headlights a lot. Hence I didn't notice I had a problem until this week. 1997 90, 300Tdi, unmodified. Symptoms: Temp gauge goes from below half (normal) to the red when headlights turned on (only when engine is warm...

I'm suspecting something loose in the gauge, and a substitution might sort it out. However, I brimmed it yesterday and the gauge is behaving totally normally! Sods Law. Cheers

Thank you for the reply. The flickering is quite fast - not quite 1950 Morris Minor fast, but much faster than the normal damped movement. When I tested the movement before I installed the sender the movement was quite stately, perhaps 3-4 seconds from full to empty, no matter how quickly I...

So, I have filled it up twice since the last post. The needle flickers drunkenly for the first 20-30 miles and then seems to settle down. From 3/4 tank downwards, it's as steady as a rock. What can it be about a full tank that make the needle waver about? I am mystified.

This makes sense to me. When I fitted the new sender, before I put it in the tank I experimented by moving it through its range to see if I had cured the fault (gauge wouldn't read below 1/2, meaning I ran out of diesel on my first trip). I noted that the gauge worked over the full range and...