Biffdiff42 Posted March 12, 2021 Report Share Posted March 12, 2021 Hi, I have TR7 V8 conversion with some electrical issues and as the car is a recent purchase I do not not know much about its current state. I removed the dash as am hoping to install a new radio but there were no wires at all behind the radio or connecting the switches below it which are the cigarette lighter, dimmer and aerial (I I think) . I believe my car has been fitted a FHC wiring loom as there is a rear heated screen switch with wiring in the dash but the car is a DHC. We were hoping to use the power supply from this to run the radio but there is no current running to the switch and not only that but there is also no current to the relevant fuse. It appears as fuse No4 on the diagram I have. (second from top right). We suspect that the loom running to the fuse box is not supplying power to this fuse and any advice on what to test or where to look next would be much appreciated. I have also found after taking the dash off a couple of small lights which not attached to the car but look although they insert in to a panel on the dash but I cannot see any obvious slots for them. Any ideas on where they fit and if they are attached to a 'light switched' live or an ignition live ? Quote Link to post Share on other sites
HowardB Posted March 13, 2021 Report Share Posted March 13, 2021 What year is the car? This significantly effects the wiring diagram Quote Link to post Share on other sites
Biffdiff42 Posted March 13, 2021 Author Report Share Posted March 13, 2021 Built in May 1980 Quote Link to post Share on other sites
HowardB Posted March 13, 2021 Report Share Posted March 13, 2021 OK this redrawn wiring diagram for the 80/81 model should help you sort out the missing cabling:- TR7 Circuit Diagrams - redrawn Hope this helps Howard Quote Link to post Share on other sites
Biffdiff42 Posted March 13, 2021 Author Report Share Posted March 13, 2021 many thanks, that is much appreciated. Jonathan Quote Link to post Share on other sites
Biffdiff42 Posted March 14, 2021 Author Report Share Posted March 14, 2021 After some further digging with the multimeter we may have isolated one of the electrical problems but need to try and identify where in the loom the problem comes from. The left hand headlight is fine on dip but the right one does not work and we have worked back through the wiring in the fuse box, switch and dip/main beam switch on the steering column. We have good continuity until the Blue/Red wire which feeds both headlamps on dip but splits before the fuse box and I have marked this on the two pics below (see arrow). But can anyone help in identifying where physically this split is made on the loom ? Any guidance would be much appreciated. Quote Link to post Share on other sites
BusheyTrader Posted May 5, 2021 Report Share Posted May 5, 2021 The light in your hand clips into the plastic bar that labels the hazard switch, headlight switch etc. There should be two of them. The DHC and FHC share the same loom, so the heated rear window wire is redundant on a DHC unless like me and others with a V8 conversion use it to power their electric fuel pump. Cleaning the wiring connectors in the front corners of the engine can bring the headlights and their motors back to life as they fur up readily. Don’t be tempted to work on the headlights or their pods without disconnecting the battery first, unless you want to lose some fingers, it has happened. Quote Link to post Share on other sites
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