Indicator flasher loose - causing shorts

[dgently]

The "flasher can" for my indicators is hanging loose behind the dash and seems to be shorting out part of my ignition circuit. When acting up, my temp and fuel guages drop to zero, heater fan and indicators don't work, Problem goes away if I just hold the little can against the steering bracket - i.e. if I earth the housing. Then everything works perfectly

The unit has four connectors.

Can anyone tell me where this is normally mounts, and how I can make sure it's properly earth. Is it actually just buggered?

[oldelanman]

Silly question maybe but are you sure it's your flasher unit - they don't generally have 4 connectors.

Could it be the voltage stabiliser ? If so it should be mounted on the back of the speedo.

[dgently]

Thank you, that's it! Has a hole in a tab to attach to one of the posts on the speedo. I assumed it was the indicator because my instruments would wig out usually when I used the indicators. I thought only the instruments were in the circuit with the regulator.

Mine has only 2 wires connected though. Any clues as to which wires should be on there?

[oldelanman]

It is actually screwed directly to the case of the speedo and the tab on the mounting bracket locates in a hole in the case to ensure it's the right way up - correct orientation is important for the unit to operate properly.

I don't know what car you have but in the Elan the flasher unit and the stabiliser share the same power supply which may be why your problem occurs only when you use the indicators but I don't really know.

If you only have 2 wires connected to the unit one will be the 12volt supply - live with ignition on - and the other will be the 10volt stabilised feed to the instrument(s). According to my workshop manual both wires are green so you would need to use a voltmeter to establish which is which. I am not sure but I think the 12volt connection on the stabiliser may be marked B.

[dgently]

Thanks for the pic, very clear. The unit in my +2 has 4 spades - yours seems to be earthed (black wire?) via a fifth.

I'll be footling around upside down for a while trying to locate the fixing hole to the set screw on the back of the speedo. I've ordered one of these http://www.ebay.co.uk/itm/400516822467 because my guages are erratic at the best of times. Spent months fretting about a non-existent engine cooling problem

Thanks again, you've been really helpful!

[billwill]

The stabaliser works by turning the output on or off to create an AVERAGE of the target voltage (10volts) . Inside is a bimettalic contact strip which bends due to a heating coil wound around it.

It should only be used to feed power to slow instruments such as the slow type fuel gauge. Feeding fast instruments with it will make them erratic.

Modern replacements are transistor stabalisers, with permanent output at the target voltage.

[dgently]

The "fifth" spade connector I thought was missing from mine actually appeared to have broken off at some point. I jury-rigged an new one to the "stump" but it made no difference. Fixed the problem short term by just removing the old stabiliser and connecting the two wires. Random shorts/failures eliminated, and the gauges now read as they did (i.e. wrong). Obviously it was well and truly kaputt.

Will wait for the electronic version I linked above to arrive and hopefully give me a meaningful read on engine temp.

Sincere thanks to all for your help and input!

[dgently]

Got my new modern transistor (linked above), great value at ?5.

Mixed results. Fuel and temp now rock steady, fuel guage reading credible but temp guage seems to level at at 80 which I expected by be 90. The stabilisor is absolutely doing it's job, and after widening the mounting hole a little was easy to mount via set-screw to the back of the speedo.

Bad news is half my dash seems to be incorrectly wired through this stabilisor, so wipers, heater fan and indicators hardly work at all now @ 10V. Have taken the stabilisor back out until I figure out how to isolate it to the instrument feed. My standard +2 has a very simple wiring diagram, but I couldn't spot the stabilisor on it!

Needless to say, the wiring doesn't look simple in real life

[oldelanman]

It could be you have an earth problem.
You may have done this already but to check if the heater, wipers and indicators have been wired incorrectly just disconnect the wires from your voltage stabiliser (you said earlier there are only two ) - don't join them together. If just your intruments stop working the wiring is correct and the problem is likely to be a bad earth but if your heater, wipers and indicators also stop working then they are wired wrongly.

I don't know if the +2 is the same but in the Elan the heater, wipers and indicators etc are all earthed on the body mount bolts which also secure the bottom of the dash to the tunnel.

[dgently]

Thanks again oldelanman, and yes I lose gauges, indicators, fan & wipers if the two wires to the stabiliser aren't connected.

If I've understood you correctly, all but the gauges should have their own route to earth "before" the stabiliser, or do they typically share a route to earth? If their earth was poor, they would all be earthing via the gauges?

[MickG]

Although I don?t own a plus 2 I do have the workshop manual and wiring diagrams. If your diagram is the same as mine it is either numbered LSL134 (RB 340 control box) or LSL140 (RB106 control box).
The voltage stabiliser is shown between the speedo and the tacho and is called ?voltstab?. Hopefully yours is the same otherwise this explanation is going to be a little difficult to understand.
The wiring colour code is not the same as the Elan and this could be where the misunderstanding is occurring.
The feed to the stabiliser (12V) is coloured RG, red/green, and comes from the ignition switch terminal 2 and loops onto the tacho. The feed as previously stated goes to the B terminal (battery) on the stabiliser, The I terminal (instruments) feeds the temp and fuel gauges only nothing else. Going by the diagram I would assume this to be a green wire.
Another green wire coming from the fuse box feeds the heater switch, indicator flasher, wiper switch, oil pressure gauge, rear heated windscreen, hand break warning light and finally the low fuel level light in the speedo. This circuit is 12Volts.
You need to check the voltages present and make sure that these two circuits are completely separate .
In a nut shell the stabiliser only feeds the fuel and temp gauge nothing else.

Best of luck

Regards Mick G

PS I cannot photocopy the diagram as it is A3 and my copier (when it works) can only manage A4
PPS I have just been looking at the manual again and found shed loads of diagrams. Although the above advice holds true the colour codes will change.
As long as you do not have a +2s or +2s130 the advice given in the first instance is correct.
Please let me know the model type