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MG TD TF 1500 - Left low beam

Have had a low beam go out without the bulb being burned out... played with it (P700's) a week or two ago and it came back on...this time it stays out. Seems to have power on one of the two wires but won't power the bulb unless I turn the bulb around (and that won't work on BPF if I try to put it back in the holder).
I'm thinking that if my bulb won't light, there shouldn't be any power in either line on low beam?
Want to trace the wire from either the dip switch or the point where the wires go to the lights from a junction...anyone know physically where the junction is, or are they separate lines from the foot dipper?
I have a wiring diagram, but that doesn't show the actual location of the wires.
gblawson - #27667

Don't know about the TD Gordon but on the TF there is a bullet connection just inside the side panel and from there it's into the harness and then comes out of the harness at the floor dip switch. 3 poles, One to high beam, one to low beam and one power in.
Hope that helps.

LaVerne
LED DOWNEY

Thanks LaVerne... just not sure why one of the wires to the bulb is hot when the bulb is not lit.... Tonight it came on for a few minutes, then went out when I turned them off and back on again!
gblawson - #27667

I have two wires going to the bulb connector and a ground on the frame of the light.
I'm assuming power goes to one contact on low beam and then either the other or to both on high beam?
gblawson - #27667

Interesting... took out the 'good' side and when i touched the contacts of the bulb to the connector without the ground, the bulb lit dimly(either way around)...when I grounded the bulb it shone brighter.
Wiggled the wires at the dip switch and at each spade connector on the 'bad' side and it now is on...! Now to see which of the connectors is bad...assume the dip switch would be ok as it would send power out to both headlamps?
Of course the two bunches of bullet connectors are clipped to the frame and all nice and 'tight' together.
gblawson - #27667

Gord,

I assume the main beam on the affected lamp is OK, if that's the case then the ground from the bulb holder is good. [Main and dip beam share the same ground return]. My best guess is that you have corrosion in one of the bullet (snap) connectors between the dip switch and lamp unit. The mystery of power at the bulb holder is explained by the fact that you will get a multimeter reading of potential on no load cos the corrosion will pass potential. but when you try to load the circuit the corrosion will not pass the current. Not sure exactly where the bullet connectors are on the TF, there will be a double one soon after the dip switch, which splits the feed to both headlamps. and a single in each wire near the lamp fitting (to enable the complete lamp to be removed). These single ones are likely to be just inside the inner wheel arch panel. I had a similar problem with a rear brake light where PO had pushed the bare cable into the bullet connector - a quick application of solder soon sorted that.

Good Luck
Graham
TD/C 7822
G.D. Smith

I checked this morning and found the two connectors...one double one for the headlamp under the fender (on which the rubber was all but gone) and a clump along the frame under the bonnet. I treated all the connectors with 'stabilant 22' a connection enhancer and it is now working...will check it again tonight and if all is well will put some heat shrink around the connection. The grouping of connectors along the frame was beside the oil pump and a couple of them were coated with oil?
It was on the good side that i got the slight glow in the bulb and when i grounded it, it glowed normal.
(By the way, it is a TD)
gblawson - #27667

BRILL, Glad you found the gremlin. Yup I realised my TD TF mistake after posting, obviously from the #.
G.D. Smith

Went out last night and it was out again... think i have to pull the 'oil' covered clump apart and clean all the contacts. At least with oil on them, they shouldn't be rusted!!!! (always try to remain positive).
gblawson - TD#27667

This thread was discussed between 17/08/2006 and 19/08/2006

MG TD TF 1500 index

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