Author Topic: Earthing of components  (Read 2366 times)

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Offline fulmine

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Earthing of components
« on: Wednesday,January 18, 2017, 02:23:11 PM »
Hello, the "electric system" of my 72 twin cam likes to joke sometimes...like the right indicator sometimes works,sometimes no. So i'd like to do something, i was thinking to start from the earthing (ground) points, but i don't have idea where they are. Suggestions? :help:
Lotus Europa Twin Cam 1972

Offline BDA

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Re: Earthing of components
« Reply #1 on: Wednesday,January 18, 2017, 04:44:43 PM »
Hi Fulmine,


FYI - I think the probably belongs in the Garage forum, but Joe will take care of that.


I would first make sure all the turn signal lamps are properly grounded. They should be the easiest to get to. The front lights are probably grounded to the steel "closing plate - chassis to body". I think the rear are grounded near the end of the frame.

Then I'd check the interior grounds. There are a few places where dash electrics are gounded - where the bottom of the dash is attached to the frame (under the console cover in front of the shifter. IIRC, some things are also grounded on the brackets that pick up the bottom of the dash on either side in front of the doors. I think the metal back to thepad on the bottom of the dash is what connects those ends and is grounded, as I say, where the dash is attached to the frame. The wiring diagram for the TC doesn't show a ground for the steering column switches so I think the steering column is probably grounded (sorry can't say where).


I wish I could be more definitive. Maybe someone will chime in with better first places to check but I think you're going to have to get acquainted with the "Lotus Position". Something to prop up your head so not ALL of your blood rushes to your head would be a valuable thing.


Good luck!

(edit - somehow I got a bunch of formatting characters in my message so the whole message didn't show up. This should be better)
« Last Edit: Wednesday,January 18, 2017, 11:27:36 PM by BDA »

Offline EuropaTC

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Re: Earthing of components
« Reply #2 on: Wednesday,January 18, 2017, 10:35:35 PM »
Hello, the "electric system" of my 72 twin cam likes to joke sometimes...like the right indicator sometimes works,sometimes no. So i'd like to do something, i was thinking to start from the earthing (ground) points, but i don't have idea where they are. Suggestions? :help:

As BDA says, this sounds very much like an earthing problem.  The light units normally have an individual ground wire (black) which goes from the mounting bolts on the base of each unit. Often the same earth wire will be linked to several lamps and then, to make matters worse, perhaps a bullet connector at some point in the loom before it goes to the chassis as a main earth conductor.

Trouble shooting is simple but slow. For most checks like this I have a long length of wire with crocodile clips at either end which makes it simple to provide a certain earth link. If that makes the light work, then job done. For something which is intermittent it's less certain so as a first shot I would remove the lamp base, clean it up and re-make the earth connection. 9 times out of 10 that will solve the problem.

For a long term solution it's fairly simple to buy the connectors and make up new earth wires with soldered connections. I used a heavier gauge wire and it's basically fit and forget for my lifetime !

Brian

edit to add - for things like the front indicators and anything else in that vicinity I often find it easier to remove the front grille and work through the opening rather than struggle round the bonnet lid.  In fact my grille is held on with two small hinges at the bottom & cable ties at the top so it can lie flat when needed. Heresy I know, but it's so much easier.....

Offline fulmine

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Re: Earthing of components
« Reply #3 on: Thursday,January 19, 2017, 08:29:24 AM »
Today I started to have a look, i decided to spray wd40 on some connections. I found the main earthing point in the engine bay, one behind the dash (on the left side behind the ashtray) and one on the bottom of the "radiator bay". After all i discover that all the panel lights don't work.... :WTF:
The main problem, I think, are all the connections behind the dashboard....are soooo chaotic and not to much comfortable to work in....
Lotus Europa Twin Cam 1972

Offline BDA

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Re: Earthing of components
« Reply #4 on: Thursday,January 19, 2017, 08:43:01 AM »
What!? You don't like the Lotus Position?  :D

Offline fulmine

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Re: Earthing of components
« Reply #5 on: Thursday,January 19, 2017, 08:50:55 AM »
 :FUNNY:
Lotus Europa Twin Cam 1972

Offline Grumblebuns

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Re: Earthing of components
« Reply #6 on: Friday,January 20, 2017, 07:25:53 AM »
Wondering if your twin cam is a European spec or an imported Federal car. The Federal Europas have DB10 relay that also affects the indicator operation.

Offline fulmine

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Re: Earthing of components
« Reply #7 on: Friday,January 20, 2017, 10:27:01 AM »
Mine is a Uk spec rhd....
Lotus Europa Twin Cam 1972