Strange Electrical Fault On High Beam

[mclean83]

This one has been puzzling me so I just wondered if anyone has has any similar problems? When I switch to high beam in my 87 1600gt, the ignition warning light flashes once as i pull the stalk towards me and the rev counter drops to 0 rpm and the high beam warning light doesnt illuminate. The actual lights operate on full beam as normal.

I have looked through the wiring diagrams but I cant see any obvious connection between the two. Any advice would be gratefully recieved.

Thanks in advance.

[the edmundator]

Same thing happens in my GTII at the moment. There were a couple of threads about similar problems a short while back, and the general conclusion was that it's always an earthing problem somewhere. The earth strap to the rocker cover was high on the list of suspicious candidates.

[Nate]

earth fault or loose connection to the rear of the clocks. check and clean all earths that you can find and give the connectors on the back of the clocks a good wiggle

[monzajake]

check the brown earth wire that is / should be connected to the back of the rocker cover on the right hand corner.
Said wire come's from the main loom that also has the dizzy wiring loom, oil presure switch wires etc...

[mclean83]

Thanks for the responses - I will have a look at the weekend and report back. These dark evenings are a pain in the backside! Thinking about it though I did replace the rocker gasket a few months ago...................

[mclean83]

You were spot on, I cleaned to the connections to the brown wire between the rocker cover and the carb, they were quite corroded and oiled up. Everthing now works as it should. Thanks again for all the spot on advice.

Will

[monzajake]

no probs will.

[mclean83]

This ones come back now, I have checked the earth which was at fault last time and all seems good. I have checked the earth strap between the rocker cover stud and the coil mounting and that seems ok too.

Strangeley I have also noticed that when I pull the high beam flasher switch with the engine switched off and the headlights lights switched on the high beam warning light lights up very dim and the heater fan and wipers kick in too!

I have spent all weekend looking for the problem but Im stumped now, has anyone any ideas?

Thanks

Will

[Nate]

it's an earth fault. the earth the lights should use is dodgy, so they are earthing out via fan / wipers etc. check the earth connections next to the fuse box as a starting point

[mclean83]

Thanks Nate, I checked those connections today, all seems good. I'll keep checking this week. Is there an earth point for the lights at the front end?

[Nate]

iirc they have an earth supplied in the loom. can't remember where it connects to the chassis though

[mclean83]

The Haynes manual shows the front lights as been earthed at earth point 15 - Earth Point in front loom, but Im not sure where that is and I can't see anything obvious - Any Ideas anyone?

Also looking at the manual, all the affected items (high beam warning, rev counter, wipers and heater) are earthed at earth point 10 - The earth point on the relay plate so its all pointing towards that, but when I checked that it seemed spot on!

Strange really, last time I had exactly the same problem I cleaned up the earth between the rocker cover and the carb and that sorted it for a while, is that just coincidence? I cant see what difference that would make but it seemed to work at the time!

[Nate]

The Haynes manual shows the front lights as been earthed at earth point 15 - Earth Point in front loom, but Im not sure where that is and I can't see anything obvious - Any Ideas anyone?

i think this is an earth point inside the loom - loads of earth wires together which are then half crimped and half soldered kinda thing. the source of many a good electrical fault. you could try temporarily ading an earth to selected points and see what makes it work. when you find it, ass that one in permenantly. do that make sense? i been drinking