RobRennie Posted December 17, 2021 Report Share Posted December 17, 2021 Hi, Before I put the dash back on I thought I would look at some intermittent faults - headlights and side lights.. I have noticed that when I move the big lump of wires behind the dash they will come on and go off... As part of feeling my way round I have noticed that the Brown / White and Blue wires are really quite warm when the lights are working - the lights are standard - seems a bit odd to me, would that suggest the wires have had their day and need replacing? Also, they seem to have some kind of crimped metal connector on them which also seems to be on the wiring diagram - that is properly warm! Your thoughts would be appreciated. Quote Link to post Share on other sites
Steves_TR6 Posted December 17, 2021 Report Share Posted December 17, 2021 The headlamps draw quite lot of power which translates to heat if there is resistance in the wiring. best option is to add relays to the dipped and main beam circuits. if you fit the relays in the NSF corner of the car then you can feed the relay trigger from the existing wiring and just add new, fused, power feed wiring. this way the old wiring is undisturbed but virtually all the load is taken off of it, AND you dont need to cut ANY of the original loom HTH steve Quote Link to post Share on other sites
RobH Posted December 17, 2021 Report Share Posted December 17, 2021 (edited) The heat you feel is probably coming from a bad connection in that crimp and is being conducted along the wires. Wires do not just get hotter with age - something is wrong as you obviously have an intermittent connection. The connection needs to be sorted as a minimum. If you are going to retain halogen lamps then relays, as Steve suggests, would be a good idea but fix any fault first. Edited December 17, 2021 by RobH Quote Link to post Share on other sites
trchris Posted December 17, 2021 Report Share Posted December 17, 2021 Hi As RobH says you need to cure the fault before you do anything else adding relays is also the best option for the headlight circuits as Steve suggests one for dip another for main Chris Quote Link to post Share on other sites
RobRennie Posted December 17, 2021 Author Report Share Posted December 17, 2021 Thank you. Relays it is then! - and I wanted to use the now redundant overdrive lever to use for main beam - so can build it in. I appreciate the idea of putting the relay up front! That should save some effort - you suggest NSF - is the because the wiring to the offside shoots off from the nearside? Quote Link to post Share on other sites
Steves_TR6 Posted December 17, 2021 Report Share Posted December 17, 2021 Yes, IIRC the main loom runs up the passenger side, rhd, and then a spur heads across in front of the radiator for the rhs do heed the advice from Rob too, and look for a corroded/loose connection that’s causing the intermittent fault and resistance in the first place ! good luck ! steve ps, have you removed overdrive then?, or moved the switch?? Quote Link to post Share on other sites
poolboy Posted December 17, 2021 Report Share Posted December 17, 2021 Left hand drive but I think this is what Steve is describing Quote Link to post Share on other sites
RobRennie Posted December 18, 2021 Author Report Share Posted December 18, 2021 Thank you Gentlemen - that is more than helpful - unfortunately I am under Management Instructions this weekend, we are off to her Brothers - so unable to attempt this until next week. Steve, totally on that fault, as the fault is the loss of headlight and sidelight, reading other posts, seems likely that connector on the Brown/White wire is the culprit - so I will get a new one in there - I guess common sense would say to do that and check for heat - then change the wiring, so I am sure it is fixed. The reason for loss of overdrive is previous owner replaced the engine and gearbox with a BMW set, 2.5 6cyl and 5 speed box - despite alot of work being done, the wiring for the overdrive is still there in the engine bay. Thanks again all. Quote Link to post Share on other sites
tthomson Posted December 18, 2021 Report Share Posted December 18, 2021 (edited) I am agreement with others that relays are a good option. The attached wiring diagram is how I did this. If you are intending to continue using Halogen headlamps, there is a good argument for using separate relays for dip and main, although I have not found this necessary. TT Edited December 18, 2021 by tthomson Quote Link to post Share on other sites
astontr6 Posted December 20, 2021 Report Share Posted December 20, 2021 On 12/17/2021 at 2:46 PM, RobH said: The heat you feel is probably coming from a bad connection in that crimp and is being conducted along the wires. Wires do not just get hotter with age - something is wrong as you obviously have an intermittent connection. The connection needs to be sorted as a minimum. If you are going to retain halogen lamps then relays, as Steve suggests, would be a good idea but fix any fault first. In my experience TRs have a known history of the main cable harness going up in fire and smoke! It has happen to a number of members in our group. So that problem needs to be fixed as a priority as already stated. Bruce. Quote Link to post Share on other sites
stuart Posted December 20, 2021 Report Share Posted December 20, 2021 37 minutes ago, astontr6 said: In my experience TRs have a known history of the main cable harness going up in fire and smoke! It has happen to a number of members in our group. So that problem needs to be fixed as a priority as already stated. Bruce. Really? First its been mentioned on here. Stuart. Quote Link to post Share on other sites
astontr6 Posted December 20, 2021 Report Share Posted December 20, 2021 1 hour ago, stuart said: Really? First its been mentioned on here. Stuart. I am surprised that you are not familiar with this problem? I have been present when one TR harness went up in smoke, it was lucky that he had a battery disconnect on the main live feed. But it still wrote the harness off. It was a AA recovery job? Bruce. Quote Link to post Share on other sites
stuart Posted December 20, 2021 Report Share Posted December 20, 2021 46 minutes ago, astontr6 said: I am surprised that you are not familiar with this problem? I have been present when one TR harness went up in smoke, it was lucky that he had a battery disconnect on the main live feed. But it still wrote the harness off. It was a AA recovery job? Bruce. Ive never had to replace a harness for this reason, lots for old age or bodges (which I would suspect was the cause of the one you witnessed) but none for spontaneous combustion. Stuart. Quote Link to post Share on other sites
Mike C Posted December 20, 2021 Report Share Posted December 20, 2021 A battery disconnect is always a good idea for an old car with original wiring modified by 50 years of owners fiddling- RobRennie's "big lump of wires" sounds ominous. I disconnect my battery whenever I leave the car for more than a few days. Quote Link to post Share on other sites
RobRennie Posted December 20, 2021 Author Report Share Posted December 20, 2021 Tony, Now that is an elegant solution - thank you for sharing the diagram - until I saw your post, I was planning on removing the foot button - but I will reconsider that now. I think I have the standard headlights - not sure if they are halogen, but they are as bright as a NAAFI candle at best! Quote Link to post Share on other sites
RobRennie Posted December 20, 2021 Author Report Share Posted December 20, 2021 Mike C - first off, thanks for not mentioning the cricket.... Funny enough, when I started to mooch about it felt more than 'sketchy'! - So battery is firmly disconnected. The car is a classic of folk adding and changing and not taking time to re-route wires - so it is all jumbled up - I have plodded through about a third of it and sorted them out- including running a new un-switched but fused permanent live wire, this to remove some wires that were scotchlocked on... I am waiting for new correct sized crimps to arrive before changing the main wire Thank you all - much appreciated. Quote Link to post Share on other sites
stuart Posted December 21, 2021 Report Share Posted December 21, 2021 11 hours ago, RobRennie said: Mike C - first off, thanks for not mentioning the cricket.... Funny enough, when I started to mooch about it felt more than 'sketchy'! - So battery is firmly disconnected. The car is a classic of folk adding and changing and not taking time to re-route wires - so it is all jumbled up - I have plodded through about a third of it and sorted them out- including running a new un-switched but fused permanent live wire, this to remove some wires that were scotchlocked on... I am waiting for new correct sized crimps to arrive before changing the main wire Thank you all - much appreciated. Sounds to me as if you would have been better off going for a new loom, scotchlocks are a real bodge and whenever I see thats been done to a customers car I always recommend a new loom as you can guarantee that theres more problems lurking that you cant see. Stuart. Quote Link to post Share on other sites
RobRennie Posted December 21, 2021 Author Report Share Posted December 21, 2021 Hi Stuart, You may well be correct. That may be the project for 2022 Winter The main prob with the loom is all the non-standard stuff created by the implant of the BMW engine - so a new look may not be that helpful. After a good day in the garage it is looking somewhat better - hopefully I will get more playtime to further finesse it! Quote Link to post Share on other sites
stuart Posted December 22, 2021 Report Share Posted December 22, 2021 14 hours ago, RobRennie said: Hi Stuart, You may well be correct. That may be the project for 2022 Winter The main prob with the loom is all the non-standard stuff created by the implant of the BMW engine - so a new look may not be that helpful. After a good day in the garage it is looking somewhat better - hopefully I will get more playtime to further finesse it! You can get bespoke looms ready made to suit as long as you know what the new engine management system requires. Thats not difficult. Stuart. Quote Link to post Share on other sites
RobRennie Posted December 22, 2021 Author Report Share Posted December 22, 2021 Thank you Stuart - I didn't know that - that would deffo be and end game for the car. Quote Link to post Share on other sites
RobRennie Posted January 7, 2022 Author Report Share Posted January 7, 2022 Hi All, just to give the end details to the question I started with. I replaced the connectors and the warm wiring disappeared, so as suggested on here, it was high resistance caused by age etc... I also replaced the foot hi / lo switch with the do called VW relay. So the flash on the light switch now engages high beam if the lights are on or still act as a flash if the lights are not switched on. Very easy to wire in. Each of the three wires on the foot switch have a terminal to go to on the relay. Took the live feed to the flasher to the relay, connected one side of the two wires to the flasher switch to the relay and the other to earth and it works a charm. I am going to fit the LED kit from Messrs 4Sight Automotive, but that will be after a few more things on the must do list. As always, thank you for your advice. Quote Link to post Share on other sites
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