Ignition light

Technical MGB discussion
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Tony Lilly
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Re: Ignition light

Post by Tony Lilly »

Alternator! Now changed and all good. MoT as well - one minor snag - one happy boy here!
Thanks for all your help.
''It's taken me 35 years to get an MGB GT''
Vic Butler
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Re: Ignition light

Post by Vic Butler »

Evening Tony.
That's good. Pleased to be of assistance.
. Vic
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
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Tony Lilly
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Re: Ignition light

Post by Tony Lilly »

Hi again everyone. (1979 B GT)
I'm certain I saw a thread on here about the indicators not flashing on one side but, as my sons say, perhaps I'm just getting old! Previous posts describe the snag I had and that was fixed by new alternator and new hazard switch in the cockpit. While the B was in I also changed the hazard flasher unit, indicator flasher unit and the stalk. Boom - all good until now - 4 days or so later and I have the following snag:
- Indicators normal passenger side - exterior and dash indicator
- Drivers side - rear bulb lights but does not flash / front bulb does not work. Dash indicator is on permanently Changed bulbs over and both bulbs are good! Both bulb units/housings look very old.
- Hazards work normally, including dash indicators, except front drivers side bulb does not work.
Been reading around and picked up following:

1. Check the green/white wires in the mass of connectors by the fusebox. (Remove all bullets from the sleeve connectors (both sides), polish/clean / replace etc)
2. Could be bad connections anywhere in the circuit from the solenoid up through the ignition switch, fusebox, hazard switch, indicator flasher, indicator switch, bulb holders, connections to the body, and any of the myriad connections along that circuit.
3. Check ground wire on the front drivers housing (shared with the headlights).
4. Check the connection between the bulb holder and the base of the light unit. The front light units are probably more likely to suffer bad connections from corrosion due to their exposure to wet and salt.

Am I OK to ignore the new flasher unit (Is it just above the passengers legs? or under steering column?) and ignore the hazard switch / unit and stalk. Where is the earth for the combined headlights / indicator earth? Is the front indicator fused? Could I add that my knowledge of electrics is very poor so any in-depth diagnosis, if req'd, would be back to garage.
Thanks
''It's taken me 35 years to get an MGB GT''
Vic Butler
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Re: Ignition light

Post by Vic Butler »

Morning Tony.
The fault would appear to be with the front indicator bulb housing. If, as you say, corrosion is present then there is a bad connection or earth. The front indicator is not separately fused and as the nearside ones work and the offside rear lights but doesn't flash the relay etc are OK.
Check the front offside indicator connections. Get behind the indicator housing and wiggle the wires with the indicator on and see what happens. I suspect the whole bulb holder body needs replacing.
The flasher relay is under the dash on the driver side.
. Vic Butler
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
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Tony Lilly
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Re: Ignition light

Post by Tony Lilly »

Thanks Vic - I'll give it a go tomorrow and report back.
''It's taken me 35 years to get an MGB GT''
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Tony Lilly
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Re: Ignition light

Post by Tony Lilly »

Had a spare few minutes! Took the cover off, bulb out and housing out. Took the black wire off, removed the brass type bullet and cleaned the bare wires and the bullet with wet/dry and a cloth. Pushed the green wire and the circular connector/spring out the front and cleaned up. Ran some wet/dry around the bulb holder. Then it got dark and really wet so stopped.
Bearing in mind my very limited knowledge of electrics, before I re-assemble/refit can I place the bulb on a cloth and manually hold the wires against it while son uses the stalk to turn on? If so - green to the base and black to ??
Thanks
''It's taken me 35 years to get an MGB GT''
Vic Butler
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Re: Ignition light

Post by Vic Butler »

Morning Tony.
Green to the base of the bulb and black to the brass part.
. Vic Butler
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
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Tony Lilly
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Re: Ignition light

Post by Tony Lilly »

I think I'm being a bit non-electric here and I am quite old! I'm happy with the green to the base of the bulb (small protruding stud) so now if I touch the black against the silver outside of the bulb (by the two locking studs that protrude) it should light/flash when son flicks the stalk? Thanks
''It's taken me 35 years to get an MGB GT''
Vic Butler
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Re: Ignition light

Post by Vic Butler »

Afternoon Tony.
Yes, that's correct.
I agree electrics can be a minefield. I managed to teach myself to deal with most problems on classic vehicles but as for modern cars I'd be scared of doing some expensive damage by just poking at something.
. Vic Butler
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
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Tony Lilly
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Joined: Sat May 13, 2017 9:29 pm
Forename: Tony
Surname: Lilly
Location: cornwall

Re: Ignition light

Post by Tony Lilly »

Well - wires to the bulb didn't work! So I followed the wires up through into the engine room ensured all the connectors were tight (did hear a small 'click' on one as I pushed and pulled) and ... bingo!! I'm now a complete flasher.
Thanks Vic.
''It's taken me 35 years to get an MGB GT''
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