Speedy indicators
Discussion
My right-hand indicators have started blinking much faster than normal, but the left-hand ones are fine. Looks like the driver's side front bulb has blown, but would this affect the speed of the others? The bible says no, but anyone experienced this? Is bulb changing easy? (in any other car, I wouldn't ask this!)
Steve!! Everyone says you're wrong!!This happened to me last week, right hand side indicators started flashing madly. Turned out to be the rear bulb gone, when i dismantled the unit in the boot the bulb had come loose in the socket and was rattling around in the housing. Refitted it all and worked ok, bulb not even blown. Indicators then returned to normal speed.
First I say that the unit is electronic and that the rate does not change with the number of bulbs that are connected which is why the hazards are dead easy to do.
This then leads to the point about the electromechanical flasher... Nice theory but please explain why the flashing rate does not not increase in speed when you put your hazards on which doubles the load by decreasing the resistence by half?
The old electromechanical ones used to have power switched to the unit and then fed to the appropriate indicators. The unit that TVR use only works when the load is applied. 12 volts is contantly applied. As bulbs normally fail O/C then the load is actually reduced which also contradicts the theory. If the bulb fails S/C (not the same as adding more bulbs) then that could upset the unit by draining the capacitor that sets the timing. More load, more drive current, less time before the capacitor resets.
Steve
>> Edited by shpub on Monday 17th March 07:17
This then leads to the point about the electromechanical flasher... Nice theory but please explain why the flashing rate does not not increase in speed when you put your hazards on which doubles the load by decreasing the resistence by half?
The old electromechanical ones used to have power switched to the unit and then fed to the appropriate indicators. The unit that TVR use only works when the load is applied. 12 volts is contantly applied. As bulbs normally fail O/C then the load is actually reduced which also contradicts the theory. If the bulb fails S/C (not the same as adding more bulbs) then that could upset the unit by draining the capacitor that sets the timing. More load, more drive current, less time before the capacitor resets.
Steve
>> Edited by shpub on Monday 17th March 07:17
Steve, your reply sounds reasonable, but then, so does MrsD's reply, which is also in line with a Lucas Engineer's comments to me when I was having an electrical problem fixed a few years ago.
Could the circuit not be designed to alter the flash rate if a bulb has failed to give you a warning that this has happened?
Could the circuit not be designed to alter the flash rate if a bulb has failed to give you a warning that this has happened?
While changing to LED indicators i had to alter the flasher settings. The unit will detect a bulb gone,it has a shunt wire inside detecting voltage drop across it, if the drop is sufficient then the flash timing(electronic) is standard, if not enough, it flashes fast. Thats why it doesnt go fast if hazards are on.
My griff developed this problem the morning of its MOT.
Nearside flashed quickly but drivers side ok.
Anyway, I fiddled with the wires from the indicator housing & taped them up,as a temporary measure.
That temporary measure got me thru the MOT ( fingers were crossed ) & only reminded me this week when it started again.
Where is the best place to get a replacement indicator housing & wire section ?
Bulbs & fuses are ok.
Nearside flashed quickly but drivers side ok.
Anyway, I fiddled with the wires from the indicator housing & taped them up,as a temporary measure.
That temporary measure got me thru the MOT ( fingers were crossed ) & only reminded me this week when it started again.
Where is the best place to get a replacement indicator housing & wire section ?
Bulbs & fuses are ok.
The only car I've got my hands oily on lately uses the Lucas (the prince of darkness) flasher unit. I think my explanation is accurate as regards that one and that is what AllTorque's problem sounds like, but p'raps not. Do TVR consistently use the same parts bin ?
The Lucas (Elan S2-so prob. robbed off a 60's Ford) unit has a parallel load resistor that sinks the current when you put the hazards on.
>> Edited by mrsd on Tuesday 18th March 19:23
The Lucas (Elan S2-so prob. robbed off a 60's Ford) unit has a parallel load resistor that sinks the current when you put the hazards on.
>> Edited by mrsd on Tuesday 18th March 19:23
Hi Guys and Gals,
Thanks loads for your concerns! Spent a painful half hour tonight grappling under the car at the front (boy is it low - banged my head a few times!), ripping my hands to shreds on the rough fibre glass, laughing inanely at the godawful wiring down there. Undid the horn and got out the indicator bulb - it looked smokey, but the filament was intact. Pootled off to Halfords in the 200sx and bought a replacement. Fitted it in, and whaddya know - everything worked!! Except...... must have knocked my driving light in the process, as this now no longer works.
Doncha just love these cars! So it does look like there is a fault identifier in the indicator circuit..... 
Thanks loads for your concerns! Spent a painful half hour tonight grappling under the car at the front (boy is it low - banged my head a few times!), ripping my hands to shreds on the rough fibre glass, laughing inanely at the godawful wiring down there. Undid the horn and got out the indicator bulb - it looked smokey, but the filament was intact. Pootled off to Halfords in the 200sx and bought a replacement. Fitted it in, and whaddya know - everything worked!! Except...... must have knocked my driving light in the process, as this now no longer works.
Doncha just love these cars! So it does look like there is a fault identifier in the indicator circuit.....
mrsd said: The only car I've got my hands oily on lately uses the Lucas (the prince of darkness) flasher unit. I think my explanation is accurate as regards that one and that is what AllTorque's problem sounds like, but p'raps not. Do TVR consistently use the same parts bin ?
The Lucas (Elan S2-so prob. robbed off a 60's Ford) unit has a parallel load resistor that sinks the current when you put the hazards on.
>> Edited by mrsd on Tuesday 18th March 19:23
Yes the old type used to suffer from the problems that you describe but the Griffs and Chimaeras etc all use a modern GM sourced electronic unit which doesn't. I ended up having to source the wiring diagram from a car in bible 2 because it looked pretty wierd on first sight but once I had found the hidden diodes and other bits it is quite sensible.
Steve
AllTorque said: Hi Guys and Gals,
Spent a painful half hour tonight grappling under the car
Yes I've just take the bulb form the nearside front and am enjoying itchy fibreglass scrathes as I type this. Bit concerned as the bulb looks fine, but it's too tiresome to swap them over (arm already looks like I've had a fight with a cat) so am going to get new one tomorrow with X'd fingers
Ed
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