Neil J Posted September 1, 2014 Report Share Posted September 1, 2014 Good afternoon, First of all, all you knowledgeable folks out there, please tolerate my obvious ignorance. Electrical issues always have, and probably always will baffle me. Yesterday en-route to an event in the early morning mist, the headlamps on my 1967 TR4A decided to pack it in, (side lights still working ok as are number plate lights ect.). Immediate thought ! a fuse has gone. Checked the fuses, all ok. To confuse matters furher the hand book says the fuse holder contains two 25 amp fuses. Mine looks nothing like the illistration and has four 35 amp fuses . Get home, check my Haynes Manual and the workshop manual, both say the same thing with no reference to any changes from the 4 to a 4A. Had a look at all the connectors I can find, no apparent loose ones. Look at the wiring diagrams, maybe it's the switch ? Loosen off the plastic cowling and the securing screws to the switch, but no obvious loose or disconnected wire, not to easy to see though and I'm reluctant to take it all off from the steering column if I don't have to, plus I can't see how to do that at the moment anyway. Logic ( ha ha ) tells me it's got to be something simple. Any help greatly appreciated. Thanks for your time, John Quote Link to post Share on other sites
jamie hart Posted September 1, 2014 Report Share Posted September 1, 2014 A very quick one, check the wires are still on the foot dip switch, easy to kick them off! Quote Link to post Share on other sites
peejay4A Posted September 1, 2014 Report Share Posted September 1, 2014 Check the integrity of the bullet connectors where the loom passes over the radiator cowl. Quote Link to post Share on other sites
Neil J Posted September 1, 2014 Author Report Share Posted September 1, 2014 Thanks Jamie and peejay, I've checked the connectors across the top of the radiator cowl and they seem ok, no loose ones etc. Jamie the connections to the dipswitch are all connected, no loose ones. I've checked and I have power to the dipswitch when I operate the headlamps, so at least the lightswitch on the column is ok. Could be the dipswitch then . I'll take it off and give it a clean up, thanks for your suggestions. John Quote Link to post Share on other sites
RogerH Posted September 1, 2014 Report Share Posted September 1, 2014 (edited) Hi John, have you carried out a voltage check on the lighting loom. Have you got a wiring diagram www.advanceautowire.com Firstly check the earth wire from the headlamp to the inner wing. Starting at the bullet connector where the loom crosses the rad - has the Blue/White and or Blue/Red cables 12V. If yes, the problem is either earth or in the headlamp bowl If no then check near to the switch. there shouldn't be any fuses in the lighting circuit Has the Blue cable on the dip switch got 12V - it should have Roger Edited September 1, 2014 by RogerH Quote Link to post Share on other sites
tim hunt Posted September 1, 2014 Report Share Posted September 1, 2014 Agree with both these suggestions. However, it is also possible that both headlamps failed at the same time - ask me how I know!. You should find a single blue and white wire feeding a bullet connector above the radiator cowl, as Pete says, or possibly secured to the top of the upper valance *(radiator surround) if your car lacks the cowl. These feed the left and right main beams. remove the single blue and white wire and connect a wire from the +ve battery terminal to the bullet connector, the lights should illuminate. There is a single blue and red wire feeding two others, for the low beams, do the same exercise. if the lights now operate and you have done the other checks mentioned then have a look under the steering column inside the car. If you are my size this is much easier if you remove the driver's seat and maybe even the steering wheel as well! Check the integrity of al the bullet connectors feeding or taking power from the column switch. If they are all sound then disconnect the single brown and blue wire feeding the switch, this should be a permanent 12v supply, check this with an earthed test lamp or a test meter. If there is no power then there could be a break in this wire at the ignition switch. If, as I fear most likely, you have power to the column switch then the switch itself has developed a fault. They were not designed to handle 10A+ for decades and the contacts in yours have most likely burned out. if the headlight bulbs are OK and you are getting power to the switch you will probably find that the flasher still operates since these contacts carry current only for occasional brief periods. My light switch failed twice over some 35 years and on both occasions I removed it, carefully stripped it and rebuilt the contacts with solder, being too tight to shell out 30 or 40 quid at the time. However, more recently I fitted two fused 30A relays one each for dip and main beams and now the column switch is handling only a very small current to energise the relay and should never fail again. I used hefty wires from the battery to terminal 30 of the relay and from terminal 87 to the lights and a side benefit is reduced voltage drop and consequently brighter lights. If you do find the column switch faulty and want to remove it and fit relays feel free to PM me. I only wished I lived in the Dordogne and could pop round to give a hand! Tim Quote Link to post Share on other sites
peejay4A Posted September 1, 2014 Report Share Posted September 1, 2014 Have you lost both dip and main beam? Quote Link to post Share on other sites
stuart Posted September 1, 2014 Report Share Posted September 1, 2014 (edited) Dip switches when not used for long periods of time and especially if originals or cheap repros do sometimes have a habit of suddenly cutting the lights when used. A few quick stamps on them quite often brings them back to life. Stuart. Edited September 1, 2014 by stuart Quote Link to post Share on other sites
johnny250 Posted September 1, 2014 Report Share Posted September 1, 2014 ........ A few quick stamps on them quite often brings them back to life. Stuart........... Until the spring loaded 'cap' flies off into the darkness leaving you on full beam till you get home... don't ask etc...... john Quote Link to post Share on other sites
tim hunt Posted September 1, 2014 Report Share Posted September 1, 2014 Soon after we acquired my 4A in 1970 I decided to junk the horrible floor dip switch. The wires to this were just long enough to re-route to a robust two position on-on switch which I fitted under the dash to the right of the steering column. A rubber extension on the switch lever allows operation with the right hand still on the steering wheel. Oh the luxury of being able to dip the lights and change gear simultaneously on the occasion that this is necessary. This was a quicker and easier solution than the alternative of modifying the wiring and fitting a later type switch a la CR TR6 with side, main beam, dip and flash functions and a separate master lighting switch. Tim Quote Link to post Share on other sites
stuart Posted September 1, 2014 Report Share Posted September 1, 2014 ........ A few quick stamps on them quite often brings them back to life. Stuart........... Until the spring loaded 'cap' flies off into the darkness leaving you on full beam till you get home... don't ask etc...... john Yep been there as well! Stuart. Quote Link to post Share on other sites
Grahamgl Posted September 1, 2014 Report Share Posted September 1, 2014 I ditched my floor mounted dip switch after I read an article in TR Action which involved the use of a relay and a left hand drive overdrive switch mounted on the steering column. A simple job for an electricity ignoramus like me, it works really well and makes more room for your left foot. Graham Quote Link to post Share on other sites
Neil J Posted September 2, 2014 Author Report Share Posted September 2, 2014 Thanks for all your responses guys. Yes Pete, both high and low beam gone. Roger, I have power to the dipswitch and power out on each terminal (high and low beam), so it seems the dipswitch is ok. Checked the wiring where it crosses the cowl. Power to the low beam and high beam connections, (Blue and red and blue and white respectively). I've taken out the headlamps and the bulbs seem ok, (managed to drop one headlamp while getting it out, they do'nt bounce to well, 'sacre bleu' does'nt quite cover it ). Checked the three point plug in each headlamp bowl, power high and low beam both sides so it suggests earth nbg. I've followed the earth wires from both headlamps and they seem to go to a common bullet connector with a single earth lead disappearing into a loom and I think comes out and is earthed under the bolt holding the upper valance stay rod, by the horn (dvrs side). Although all the leads seem firm ( I can't pull them free) in the bullet connector it is a bit manky, so maybe that's where my problem lies Quote Link to post Share on other sites
RogerH Posted September 2, 2014 Report Share Posted September 2, 2014 Hi Neil, if you have power to the bulbs then it must be the earth return (mustn't it!!). Find the nearest earth bullet connector to the bulbs and short this to ground/body - the bulbs should then work!!!! Roger Quote Link to post Share on other sites
Kiwifrog Posted September 2, 2014 Report Share Posted September 2, 2014 why p#ss around, run 2 new earths one for each headlight to an appropriate point on the bodywork, that way in future if you have a dodgy earth you will only lose 1 light Cheers Alan Quote Link to post Share on other sites
Neil J Posted September 3, 2014 Author Report Share Posted September 3, 2014 We have light. Thanks chaps, sorted. John Quote Link to post Share on other sites
RogerH Posted September 3, 2014 Report Share Posted September 3, 2014 What was the problem !!!!!! Roger Quote Link to post Share on other sites
Neil J Posted September 3, 2014 Author Report Share Posted September 3, 2014 Roger, Dickie earth. The common bullet connector that I spoke of, the 'manky' one. I took a leaf out of Kiwi Frogs suggestion and ran a wire from another earth to the earth terminal on the bulb when it was in the holder, and behold - light. The bullet connector is knackered. I've another on way along with two new headlamps, ( you recall I busted one and you can only buy them in pairs it seems). They should be here by the end of the week. I might well follow Kiwi Frogs suggestion and earth each seperately, sounds sensible to me. I'll never be an auto-electrician but I've learnt a lot through this so that's all to the good. Once again thanks , John Quote Link to post Share on other sites
RogerH Posted September 3, 2014 Report Share Posted September 3, 2014 When you mention headlamps - are you running sealed beams? If so, at a suitable time consider getting headlight units that take seperate bulbs - you find a considerable improvement. Roger Quote Link to post Share on other sites
peejay4A Posted September 3, 2014 Report Share Posted September 3, 2014 What Roger says. Add Osram Nightbreaker bulbs and you have good headlamps. Quote Link to post Share on other sites
Neil J Posted September 3, 2014 Author Report Share Posted September 3, 2014 Roger and Pete, No I hav'nt got sealed beam units. When I got the car I had Halogen lights put in. The bulbs are H4 60/55. The car is RHD but as you know I live in France so they are LHD ones. I remember the lights we had on cars in the sixties, pretty pathetic compared with modern ones. But then I don't drive it much at night if I can help it. No such thing as cats eyes on the road here, so decent lights are must. Pete, what are these Osram Nightbreaker's. Are they like these modern Xenon bulbs with a very bright white light or something in between that and what I have ? John Quote Link to post Share on other sites
peejay4A Posted September 3, 2014 Report Share Posted September 3, 2014 Nightbreakers are the latest Osram development in halogen bulbs. They're very efficient compared to standard H4 bulbs but similar wattage. I have them in my Land Rover and the 4A. On the 4A they're in the headlamps and the Cibies. Here's some blurb: http://www.osram.co.uk/osram_uk/news-and-knowledge/automotive-special/night-breaker-plus-limited-edition/index.jsp Quote Link to post Share on other sites
Lebro Posted September 4, 2014 Report Share Posted September 4, 2014 Just ordered a pair of these in H4 to match my repro tripod lamps (TR3) - thanks Pete http://www.ebay.co.uk/itm/2-X-H4-12V-60-55W-OSRAM-90-NIGHTBREAKER-PLUS-HEADLIGHT-BULBS-LIMITED-EDITION-/161193682331?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2587e4659b Quote Link to post Share on other sites
Neil J Posted September 4, 2014 Author Report Share Posted September 4, 2014 Pete Thankyou for the information. I might invest in some of these. John Quote Link to post Share on other sites
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