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MG TD TF 1500 - TF Dash warning lights

Would appreciate some guidance on wiring the 3 jewel warning lights. The wiring diagram clearly shows the wire to the Direction indicator bulb with the light grounded, presumably through the housing, which seems normal.
On the Petrol warning light and the Ignition warning light it shows the wiring across the bulbs (power in and out) which would require the light assembly to be isolated from ground.
As the PO modified the dash to use other lights, none of the mounts remain. I am trying to get something working at least temporarily to sort things while I work on a new dash assembly.
Photos of others' dash assemblies show only 1 wire to each bulb and the aluminum lamp housing grounded.
What is the correct method?
thanks in advance.
Rorry
Rb Harding

Rorry, see http://www.ttalk.info/Tech/Indicators.htm for information about the warning lamps. Though written for a TD the material is valid for a TF. If you'll look at the TF wiring diagram, page N.29 of the WSM, you'll see how the petrol and ignition warning lamps have two terminals on each. Bud
Bud Krueger

Rorry,
Would my drawing of the TD dashboard wiring be of any help?

Regards
Declan

Declan Burns

Each of the assemblies should have a seperate plate with a screw connection to facilitate either a ground or a circuit...as in the charging circuit. Where you do not want the assembly grounded .. as in the charging circuit and the low fuel circuit.... a phenolic washer is placed between the jewel and the aluminium bulb holder to prevent ground. You can enlarge this photo and see that I insulated each of the bulb holders and ran a ground connection to the turn signal lamp. Pay no attention to the colors of the wires from the bulbs as I used the bulb holders an those wires on them from what I had in my spare stuff. The top connection is the low fuel warning lamp ....the middle is the charging lamp... and the bottom is the turn signal lamp. A TF does not have the resistance wiring that would be found on the TD bulb assembly.


L E D LaVerne

The petrol lamp is isolated from the ground as it earths via the low fuel float switch.
the ignition lamp is also isolated but the indicator lamp is grounded through the dash,
Originally the lenses screwed into the aluminium lamp holders which held them in place and the petrol and ignition had a plastic washer to isolate them from ground.
Ray TF 2884
Ray Lee

Thank you all for your prompt and thorough responses! I see a path forward.
I understood how the lights should work but it was not apparent how it was accomplished until the phenolic washer was introduced.
Rorry
Rb Harding

This thread was discussed on 22/08/2017

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