Thanks to all and Help please

[Mutley]

Just like to say I have visited this site quite a few times over the last year, and so finally decided to register/join only to find out that I had already done so about 6 or 7 months ago. I think it must be an age thing, memory loss and all that.

Any how you guys on her are the Mutts Nuts and as I have my first Defender 90 300tdi 1995 M reg (my pride and joy) you have saved me a small fortune, from changing the clutch master cylinder to changing all the oils and filters so a big thanks to the guys that take the time to post this useful info.

Now for the next problem, I'm no spanner man the wife knows more about the motor than me as for electrics not a prayer!... So here goes, I have noticed that when driving at night the head lights seem to pulse ie go dim then bright again as does the light on the instrument panel, also the fog light on the instrument panel seems to glow even though they its not on at the time? The only thing I have done is replace the head light bulbs from standard to some that are whiter/brighter still road legal though. Any thoughts would be gratefully appreciated Cheers Mutley

[Andrew Chua]

1. Grounding

2. alternator

3. regulator

4. battery

do you have air con on the truck? cos sometimes when it kicks in and your alternator cannot output the rush of current, things might dim slightly.

the condition and age of the battery does matter if the alternator is not working 100% well as that would be the 'reserve' bank it draws from when something with large current cuts in (main beam or a/c).

on a more elderly truck, the grounding sometimes gets a little corroded and hence this can be the start of your worst nightmares. if it's only the lights, check the main beam switch. they tend to melt in the long run hence when wobbled a little they do lose contact causing a slight dim of the lights as they go off and back on.

if it's a regulator problem, you should fix is quick as the eletrical don't seem to like high voltage and very soon more random things will happen before they burn up.

[errol209]

check the main beam switch.

^^^^ that'd my first stop ...

[Mutley]

Got the sparky to check the alternator at work and he says it's fine but does think the battery is some what small? So I'm in the process of looking for a new one, not too sure where to start on that though as all the info about batteries is Greek to me, all I seem to get from it is that bigger is better?....Will definitely check the earth and light switches as suggested, at least that gives me a staring point if only to cross them off the list of things to check, bless the little ........Cheers Mutley

[FridgeFreezer]

First off, woah there on the battery - don't rush out and do the expensive bit first when there's things you could check for free

Normally when one thing affects several others in electronics it's grounding - the electricity can't get back to the battery through the ground connection so flows back "up" something else (EG bulb in foglight switch, radio aerial cable, etc.).

There are braided earth straps between engine/gearbox and chassis, and chassis & battery. Also, most electrical parts will then have their own ground that either goes off to a connector block bolted to the body/chassis, or is just bolted directly to it. On LR, plain black wires are ground.

Second, Discos are known to have dodgy headlight wiring. Dunno why it should be so, but it can and does melt the bulb connectors and nearby wiring. If you've uprated the bulbs you may be pushing it a bit. If the connectors are in poor nick Vehicle Wiring Products can provide new connectors or even a short ready-made harness to cut back the last foot or so of wire and replace. It could be your headlight ground wire has gone south and the bulb is partly grounding back through the other half of the filament, then via the dash warning lights.

The alternator is a pretty easy one to check - you can buy traffic light style battery & alt checkers for £5-10 ish from tools shops, but for as little as £3 in Maplins/RS/CPC/etc. you could get yourself a multimeter (preferably with continuity check/buzzer and DC current) and have the ability to diagnose a load of stuff. Depending on the alternator it should be putting out 13.8-14.4v when running.

Your battery is unlikely to be causing this, even if it may technically be too small. Technology moves on, batteries get smaller for the same electrical capacity. A good battery supplier will do a "drop test" on your battery for free (and then probably try to sell you a new one regardless ), they can also sell you one that is the "right" physical size, which will fill your battery tray in a pleasing fashion and hold many more electrons than you should ever need

[Mutley]

Ok I'm now blind in one eye! Having crawled under the Landy and cleaned up the earth connection (note to myself must get some eye protectors or get the Mrs. to do it in future). Checked instrument panel, bulb blown for head lights, so that's got to be replaced and cleaned up contact points too, will check head light connections and earth tomorrow. If it wasn't a Defender I would say sod it and get a can of petrol and a box of matches, but some how there seems to be a great deal of satisfaction and self pride working on it unlike other motors I have had, maybe because it's not over complicated and a bit easier to understand/fathom. So as they say "On wards and up wards" Cheers Mutley

[errol209]

If it wasn't a Defender I would say sod it and get a can of petrol and a box of matches, but some how there seems to be a great deal of satisfaction and self pride working on it unlike other motors I have had, maybe because it's not over complicated and a bit easier to understand/fathom.

Aha! That's you bitten then - welcome!