Grabea Posted June 1, 2012 Report Share Posted June 1, 2012 The overdrive in my 6 has started behaving strangely, it was always a bit intermittent in 2nd but normally OK in 3rd and top, 3rd and in and out of o/d was ideal for round the lanes without lots of gearchanges. After a while it became a bit sluggish engaging so I thought I'd do an oil change as I'd not checked it and so decided to change it anyway. While I was under there changing the oil thought I'd have a look at the o/d filter so popped it out, quite clean, slight ring of very fine particles in way of the magnets and a very thin coating of similar particles on the magnets themselves, drained roughly 1 1/2 ltrs of oil which was quite clean so the level wasn't down that much. Put it all back together, filled with oil, ran it for a few minutes to let the oil circulate and then topped it up to the level plug. While I was underneath I discovered a pair of wires dangling down, one green the other green/ red or brown hard to tell, checked the wiring diagram and figured they were the reversing light leads from the switch on the gearbox. Fishing about under the carpets I found a matching pair of wires which when connected together the reversing lights came on, pulled the wires up through the hole in the gearbox cover ready to connect up, before I did I checked them with my meter and the car in reverse but no connection, tried all the other gears and still no connection so gathered the switch was duff. I connected the wires any way as it would stop them from dropping down on the exhaust until I get around to taking the gearbox cover off to change the switch. Now my o/d is even worse than before, hardly engages at all, usually drops in just as I'm slowing down and when I would have dropped it out had it been in, if you get what I mean. Just wondering if reconnecting the faulty reversing light switch could be the cause, maybe if it was grounded? Can't get home to try unplugging it again as I'm in Israel for the next 6 weeks!! Just wondering if any of you had had any similar experiences? Sorry it's a bit long but felt I should put in everything I'd done, I've painted the doors and fitted the door cards as well but don't think that should affect it Regards Graham Quote Link to post Share on other sites
stuart Posted June 2, 2012 Report Share Posted June 2, 2012 I would be inclined to take the gearbox cover off and check the connections on the inhibitor switches as well as the connections where the wires exit the cover at the front. By the sound of it the wires are past their best, Autosparks can supply you with a ready made section of loom for the switches http://www.autosparks.co.uk/ You may find the lack of correct switching on 2nd is down to either incorrect adjustment of the switch or the switch itself. Luckily the original Lucas switches can be dismantled to clean the contacts inside by carefully levering up the the peened over tabs on top of the switch and then remove the top cover with the contacts to reveal the internals, DONT loose the spring! Once you have cleaned the contacts apply a little vaseline to the plunger then re-assemble the switch and carefully bend down the tabs again. There are fibre shims under the switches were they screw into the box and you will need to do a little experimentation to see if you need to add or subtract them to get the correct adjustment. A road test with the cover removed is best to make sure everything is working OK but keep loose clothing away from the prop! Stuart. Quote Link to post Share on other sites
Davidw Posted June 2, 2012 Report Share Posted June 2, 2012 Just to add my (amateur) comment to Stuart's expertise. The wiring to the overdrive (and indeed on the entire car) is marginal at best and would probably not be considered fit for purpose today. The wire to the parking lights on my wife's MINI which probably have to carry about 3 amps load are about double the gauge of the O.E. overdrive wring on the TR5. Add anything up to 45 years of oxidisation into the mix and it just isn't going to be man enough to tote an 8 amps load. Auto sparks stuff is really good. I usually double the capacity I need to be on the safe side. Quote Link to post Share on other sites
Guest ntc Posted June 2, 2012 Report Share Posted June 2, 2012 The cover has to come off, oldest trick in the book they have changed the 3/4 switch (worn out) for the reverse one and left it disconnected Quote Link to post Share on other sites
Grabea Posted June 2, 2012 Author Report Share Posted June 2, 2012 Thanks for all your replies, Looks like the cover needs to come off when I get home and give everything a severe looking at!! I've already had to do quite a bit of rectification and upgrades in other areas of the wiring so looks like this is going to be next, thanks Stuart for the tip about being able to clean the contacts, sounds like your a man after my own heart, I'll always try to repair something first. Thanks again Graham Quote Link to post Share on other sites
stuart Posted June 2, 2012 Report Share Posted June 2, 2012 A lot of people (Especially the Yanks) knock the Lucas stuff but in my experience original Lucas parts can often be reclaimed as opposed to the more throw away stuff these days. Stuart. Quote Link to post Share on other sites
angelfj Posted June 2, 2012 Report Share Posted June 2, 2012 (edited) A lot of people (Especially the Yanks) knock the Lucas stuff Stuart. Sacrilege ! Edited June 2, 2012 by angelfj Quote Link to post Share on other sites
stuart Posted June 3, 2012 Report Share Posted June 3, 2012 Sacrilege ! Last time I was in the States I wandered into an Auto electrical repair shop in Santa Barbara as they were working on a cracking looking Hot rod outside and whilst chatting to the guys there we inevitably got on to the subject of Lucas electrics and despite my protestations of the fact that I have had a lot of success in reclaiming old Lucas switches etc they still kept on laughing about the fact that I was defending the stuff. Stuart. Quote Link to post Share on other sites
Grabea Posted June 3, 2012 Author Report Share Posted June 3, 2012 Who are they to disrespect the Prince of Darkness? !!!! Graham Quote Link to post Share on other sites
Denis Posted June 4, 2012 Report Share Posted June 4, 2012 Whilst in US theme... 'Over here...Over Complicated...Overdrive!' Chuck it out is my advice...'4 on the Floor' in American parlance...is da way ta go man! Quote Link to post Share on other sites
CdrRick Posted September 19, 2019 Report Share Posted September 19, 2019 Backup lights come on when reversing and also remain on when in forward gears. Any hints on fixing this. I am sure that it is a matter of hooking up the correct wires, but they all seem correct. Any thoughts? Quote Link to post Share on other sites
Mike C Posted September 19, 2019 Report Share Posted September 19, 2019 Make sure the earths in the boot are all making good contact. If the problem persists you will need to check the wiring. The backup lights are controlled by a switch on the gear selector- I'd check everything that's easier to get at before I looked at that switch and the associated wiring under the tunnel. Quote Link to post Share on other sites
RogerH Posted September 19, 2019 Report Share Posted September 19, 2019 (edited) Hi Rick, the reversing lights are powered from the Ignition Fuse through a GB switch. http://www.advanceautowire.com/tr2506.pdf The switch could be either wired badly or short circuit or too few spacers under the switch. There is no connection with the OD fault. Roger Edited September 19, 2019 by RogerH Quote Link to post Share on other sites
Mike C Posted September 19, 2019 Report Share Posted September 19, 2019 The GB switch is the one that switches them off when you disengage reverse. Quote Link to post Share on other sites
CdrRick Posted September 22, 2019 Report Share Posted September 22, 2019 Thanks Mike. Where do I find the GB switch? Is it located on the transmission or is it the backup switch on the transmission that you are referring? Appreciate your feedback Quote Link to post Share on other sites
Mike C Posted September 22, 2019 Report Share Posted September 22, 2019 Sorry for the misunderstanding, GB= gearbox switch the one on left hand side of the gearbox top cover that switches the reversing lights on when reverse is engaged. If your wiring is correct (and I'd check this first) it might be stuck in the on position or, as Roger says , may have fibre washer-spacers missing effectively jamming it on. Quote Link to post Share on other sites
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