Earth points ?

Hello guys I wanted to know more about the earth point On My 1.6 1982 gti tin top, there is a bar in the boot floor with some brown wires going to it was wondering what these wires are for and also what connects to the earth crown near the fuse box as I'm trying to sort some lighting and vdo gauge gremlins, but want to know more about these earth point TIA

They are the earth points for the rear lights and the electrical stuff in the boot lid IIRC.

The earth crown near the fuse box takes all the earths from the switches and dash and a few things from the engine bay electrics too.

Good luck!

Ian

I see so the vdo gauges and rear light issue will be best looked at in the boot area earth bar ?

Sent from my SM-J510FN using Tapatalk

I'd be surprised if the VDO's are earthed at the back of the car.

I think you may have a couple of faults that are not interconnected maybe.

Right then, erm.

Rear lights issues - check the bulbs and the metal sections of the lights for corrosion. The lights like to leak and water causes the bulb connections to corrode and the the metal sections of the plastic bulb housing to corrode as well. Doesn't take much to stop the bulbs from lighting. I'm assuming running lights rather than brake lights or indicators?
Is the earth bar nice and clean? Are the earth points looking good or all corroded? Make sure all the wires are well connected and haven't been tugged on and loosened.

For the VDO's - Can you tell if the wiring loom is original or home made? Check the bulb connections as again they corrode in the gauges.
Check to ensure that the 12v source for the gauges IS as 12v source. One of the power out tabs on the back of the fuse box is only about 5v. If this one has been used they never work correctly.

How do the earth crowns look? Nice and clean or all corroded? Any other issues going on?

Ian

Thanks Ian, the vdo gauges I have removed the bulbs but this wasn't a issue before it just appeared whilst the car was laid up for a bout a month, also how do i check the 5w connection on the fuse box as even before this issue the temp and oil pressure never really showed the proper pressure it worked but not accurate also sorry to sound silly how do i check for a 12v at the gauges I do have multi meter thanks in advance

Nowt sounds silly, if you ain't done it, you don't know, do ya?!  

I always ask the 'silly questions' as I'm constantly amazed at what people presume other people know.

Anyway…….

Put the multimeter to the 20v setting. Probably over towards about 2 o'clock on the dial.

Black probe goes onto a good earth somewhere. Try the crown to start with, if it's not doing much try the door check strap.

Red goes to what you want to check the voltage of.

In this case the input wire to the guage, it's probably red. With the car not running you should have around 12v or so. If you're way below this then you'll have to check on the back of the fuse box.

Unfortunately this means either being a contortionist or lying on you back with your head under the dash whilst trying to hold two probes onto things. It's fun  

On the end of the fuse box nearest the earth crowns will be some bare terminals. These are the auxiliary feeds. 2 or 3 are at 12v and for some reason there's one at 4v or so. I have no idea why! Some are permanent (always on) and some only come on with the ignition (when the lights are on, on the dash) you need an ignition 12v feed for the VDO's.

BTW, cabby or tintop? Engine size? Carb or GTI? They're all a bit different.

If the voltmeters working then, in theory, you have a good 12v supply and good earth for the VDO's.
If it's the oil pressure guage then it's probably the sender.

Hope that helps a bit

Ian

Thanks ian will have a look and keep you updated

Sent from my SM-J510FN using Tapatalk

Hello where could I find the 12v source from the back of the fuse box I have a early ceramic fuse , fuse box, does anyone have a picture thanks

Hello borednow didn't fully read your post , I have a 1.6 Gti tintop

Sent from my SM-J510FN using Tapatalk

One of these?



If so then one of the spades at the top and to the right in the picture should be empty.

I have found a pickup for a fuel pump on one these, but for the life of me I can't remember which spade I used. You could always tap into the fuel pump feed should you so desire.

If you do go down the splicing in route for a feed (if there are no spare spades) then carefully strip off some sheath from the wire and wrap your new wire around the core of it, solder it into position then cover with loom tape or electrical tape. Saves cutting the original loom up.

Alternatively pull a feed (in the same way) from the cigarette lighter feed.

Ian

Thanks Ian yes that is the same fuse box, so I could tap the vdo gauge earth in to my existing cigarette lighter wiring, my original  cigretter lighter wiring is not being used as I have got new wires running from the battery

Sent from my SM-J510FN using Tapatalk

ciggy lighter is permanent live so no use to you.

G spade 3 or 7 will do for an ignition feed, neither are fused. 3 is usually empty and 7 used by the rear wiper relay so will have to make/use a piggy back connector if you have a rear wiper

I see so pin 3/7 of the blank connectors are the ones to use, also do each gauge have a individual earth or are they connected to one I also looked at my earth crown and it was a little rusty one connector in particular which was at the top with a black connecting clip was really rusty, and also there was lot of condensation on the fuse box and wiring so will be drying them I have taken out the earth crown and cleaned it up and will replace the rusty connector to hopefully this would resolve it and am I right to believe that the earth crown is feed by a earth from the fuse box, also as I look now it looks like the gauges are connected to the earth crown but will follow them properly to double check and also the bulb holders are disconnected they aren't in gauges, lol hope I explained my self well as I'm laying on my back under the dash lol

Sent from my SM-J510FN using Tapatalk

will work fine either way, run 1 earth per gauge or tap them all to a thicker wire and just earth that.

the crowns have an earth to them from the main battery earth wire in the headlight loom, they are not designed to earth to the chassis though they probably will do as its decent metal on metal contact

Thanks John hope fully get is sorted it got lot of condensation which maybe throwing the gauges wild, but even before that the gauges did work but ever so lightly not giving a accurate reading apart from battery one which did occasionally show 12v

Sent from my SM-J510FN using Tapatalk

Just to confirm all the earth are all going back to the crown connector is this ok or shall I piggy back them all to either connector 3 or 7 on fuse board, once again sorry to sound nieve, just want it don't properly thanks again for all the help

Sent from my SM-J510FN using Tapatalk

all the earths to the crown is fine.

The G spade 3 or 7 would be for the power side, but if they worked before they already had a power feed. possibly the fuse has popped for it, or a dirty connection somewhere.

If the wiring is OEM they are fed from fuse 11, which also does the indicators so thats worth a look. The wire piggy backs off the ignition live to the horn relay above the fusebox

Thanks John il dry it up And clean up the crown and see if it helps just say there was rust on the crown plus one was really bad so hopefully with a bit of cleaning up and drying out it should help il.let you guys know how I get on thanks again for all your help guys much appriciated

Sent from my SM-J510FN using Tapatalk

Anyone know where I could get the bulbs and bulb holders for the gauges many thanks

Sent from my SM-J510FN using Tapatalk

take a pic of the rear of the gauges, there are a couple different styles of bulb holder