keith1948 Posted January 26, 2015 Report Share Posted January 26, 2015 Help required on position of wiring loom - drivers side or passenger side? I have an ex LHD US import that was 'converted' to RHD before I owned it. I am now thinking that after 60 years maybe the wiring loom should be replaced. I know - if it ain't broke don't fix it - but wiring doesn't last forever. The Moss catalogue shows wiring running down passenger side for a RHD. On mine it runs down the drivers side so am I to assume that during the conversion, the wiring was simply stretched/cut/modified to fit the RHD configuration but was essentially a LHD wiring on a RHD car? When I bought the car 25 years ago the headlamps still dipped to the right (with an MOT!) so anything is possible. Everything works but some of the connectors are in need of replacement. The Moss catalogue seems to show fuse box and control box and horn relay on drivers side (as on mine) but Rimmers catalogue seems to have these on passenger side. On mine the main part of wiring loom enters engine bay on drivers side. In addition the Autosparks website has information on 9 strand cable x 0.3mm vs 14 strand cable x 0.25mm. New looms will have 9 strand x 0.3mm which is rated at 5.75 amp vs the older 14 strand which is rated at 6 amp. Haven't looked in that detail at mine yet but Autosparks say lower rated newer wire is ok. Any thoughts on this? I guess as long as correct fuses fitted it should be ok? Only thing is would side/tail lights be dimmer with higher resistance 9 strand wire compared to what is likely to be 14 strand in the car at present? Any help appreciated Keith Quote Link to post Share on other sites
TRnorm Posted January 26, 2015 Report Share Posted January 26, 2015 I bought my TR4 wiring loom from Autosparks and certainly it could only fit running down the RHS. The tabs for retaining the loom were all there for the RHS. I too was puzzled by the Moss information but frankly I came to the conclusion that it was probably wrong. PS my car was a Left hooker from the US, and although I took the wiring out too many years ago to remember 100% I'm sure it run on the RHS then. Pretty much as you say yours does. I was very pleased with the Autosparks loom - nicely made with no surprises and a fair price! The cross sectional area of the 9 x 0.3 looks about 8% down but I cant see that as being a problem. after all, supposing the old wiring dropped 1 volt then the new wiring would drop just 1.08v. Actually, the purity of Cu is probably better today which would compensate a tad. Norman Quote Link to post Share on other sites
RogerH Posted January 27, 2015 Report Share Posted January 27, 2015 Hi Keith, I'm always puzzled when I look at the Moss wiring pics. My 4 and 4A are original UK RHD and the old loom was on the offside/drivers side. The autosparks loom from the mid 90's and two years ago are virtually identical. You shouldn't get a 1volt drop on the loom, maybe 0.1V if at worst. Bearing in mind that the 9 strand is only used on very low power lines. headlights, Alternator etc are on more beefy stuff. If you go for an Autosparks loom think about what else you may want to power up and where it would be on the car - Autospark will incorporate this for you into the loom. Roger Quote Link to post Share on other sites
TRnorm Posted January 27, 2015 Report Share Posted January 27, 2015 Just for clarity, I didn't mean to suggest that there would be a 1 volt drop - only that the difference in cross section area of the copper will only influence the volt drop (whatever it is). So in the case as made, if the volt drop was 1v then with the slightly reduced csa the volt drop would be just 80mv more - which relative to the nominal 12v is negligible. Norman Quote Link to post Share on other sites
keith1948 Posted January 27, 2015 Author Report Share Posted January 27, 2015 Thanks Norman & Roger As you say the wiring diagrams are confusing. So a RHD loom should fit along RHS of the car. Does that mean the LHD loom fits down passenger side? Not if my originally LHD has original position of wiring which is on RHS of car. Maybe at the factory they fitted looms on whichever side of the car they were working on?? Good idea to get Autosparks to incorporate added extras including my Otter ice detector. Just seen I must have hit wrong key and aged my car by 10 years. It is 50 this year. Time for a makeover! Keith Quote Link to post Share on other sites
stargazergs Posted January 27, 2015 Report Share Posted January 27, 2015 Hi Keith My 1965 TR4a is a LHD car which I'll be converting to RHD, the original loom that's in the car at the moment runs down the R/H side of the car which would be the same as Roger's if it were a RHD. Gavin Quote Link to post Share on other sites
TRnorm Posted January 27, 2015 Report Share Posted January 27, 2015 It seems we have yet to find anyone who's loom ever ran on the LHS! Norman Quote Link to post Share on other sites
graeme Posted January 28, 2015 Report Share Posted January 28, 2015 I believe that all TR4A's had the loom along the right side, both RHD and LHD. The Moss diagram is wrong! The TR5/6 has the loom along the left side. Take note RogerH. Cheers Graeme Quote Link to post Share on other sites
RogerH Posted January 28, 2015 Report Share Posted January 28, 2015 Quote Link to post Share on other sites
stuart Posted January 28, 2015 Report Share Posted January 28, 2015 Correct TR4/4a R/hand side and TR5/6 L/hand side The entire loom runs were changed at TR5 inception. Stuart. Quote Link to post Share on other sites
keith1948 Posted January 28, 2015 Author Report Share Posted January 28, 2015 Hello folks Thanks for all replies on this one. Right hand side it is then. For info I was looking at wiring codes because I thought it might be a good idea to add any extras e.g. fog lights, interior lights, map reading lights etc with correct wiring colours. I found this info on BS-AU7 car wiring codes which seem to match up with TR4A wiring colours quite well. Sorry it is from that 'other marque'! http://www.mgb-stuff.org.uk/colourcodes.htm No mention of ice detectors though! Keith Quote Link to post Share on other sites
stuart Posted January 28, 2015 Report Share Posted January 28, 2015 If you get an Autosparks loom made for you then they will use the correct Lucas colours for the extras anyway. Stuart. Quote Link to post Share on other sites
keith1948 Posted March 21, 2016 Author Report Share Posted March 21, 2016 Further info. My TR4A car and that belonging to Colin Boother are both originally LHD. Both have wiring loom along right hand side of car. Both were converted to RHD but wiring loom stayed on the right. Another one of our group has an original RHD UK car where the wiring loom runs down the left hand side of the car. So general rule seems to be for the TR4A that the wiring loom runs down the opposite side to the steering wheel, i.e. LHD RHS and RHD LHS. Keith Quote Link to post Share on other sites
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