mark powell Posted July 23, 2022 Report Share Posted July 23, 2022 I have, for some time, had a problem starting the Pick-up. (Herald underpinnings with 1500 engine etc). Almost every time I went to start it, the starter would give all the indications of a flat battery. So, replaced solenoid with good used one from hoard.. Nope. fitted new live 12v cable from battery to solenoid and new cable from solenoid to starter... Nope Fitted new earth cable from battery to original body earth point... Nope Still persisted in struggling. After much thought, I moved the battery earth strap to a gearbox bellhousing stud. Problem solved! When I built the new bodywork and carried out the restoration of the rest, I had the whole tub sections blasted and epoxied. I suspect that this treatment effectively insulated the body from the chassis, negating proper continuity to the starter, but retaining earthing to the lesser circuits. Maybe? Anyway, starts first time, every time, now. 1 Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 23, 2022 Report Share Posted July 23, 2022 The way to check this quickly is a set of jump leads from battery to starter motor, quickly diagnoses and rules things in or out. But thinking works also. Doug Link to comment Share on other sites More sharing options...
Chris A Posted July 23, 2022 Report Share Posted July 23, 2022 4 hours ago, dougbgt6 said: But thinking works also. I'm too old to learn a new method Link to comment Share on other sites More sharing options...
JohnD Posted July 23, 2022 Report Share Posted July 23, 2022 Triumph knew that, so they fitted an earth strap. But itvwasva manky piece of wire mesh that rusted away and was commonly not refitted in a restoration, because there was nothing there! As a result, the current has to find its own way - red hot choke cables have been known! I have a length of starter cable - nothing else will do! - between the engine block and a bolt on the bulkhead. Link to comment Share on other sites More sharing options...
mark powell Posted July 24, 2022 Author Report Share Posted July 24, 2022 Just as a note, I had all the usual earth straps ( starter cables, as above), engine to chassis, battery to bulkhead. My let-down was between the epoxied bulkhead and the epoxied chassis. I took a leaf from my Midge earthing, where the body is ply and the battery earths to the gearbox... No starting problems there! Link to comment Share on other sites More sharing options...
JohnD Posted July 24, 2022 Report Share Posted July 24, 2022 48 minutes ago, mark powell said: Just as a note, I had all the usual earth straps ( starter cables, as above), engine to chassis, battery to bulkhead. My let-down was between the epoxied bulkhead and the epoxied chassis. I took a leaf from my Midge earthing, where the body is ply and the battery earths to the gearbox... No starting problems there! I refer the Honourable Member to my previous reply. Cable block to battery earth - its the only way, for the current as much as anything else! Link to comment Share on other sites More sharing options...
mark powell Posted July 24, 2022 Author Report Share Posted July 24, 2022 Reply noted and previously acted on! Thanks! Link to comment Share on other sites More sharing options...
daverclasper Posted July 24, 2022 Report Share Posted July 24, 2022 21 hours ago, JohnD said: I have a length of starter cable - nothing else will do! - between the engine block and a bolt on the bulkhead. 7 hours ago, JohnD said: I refer the Honourable Member to my previous reply. Cable block to battery earth - its the only way, for the current as much as anything else! John. Are you saying block (or maybe bell housing will do, though is sort of indirect to block?) to bulkhead and to battery earth, via the short battery neg earth to bulkhead?, as block direct to battery earth, would side step all the other component earths that go to body?. I'm not challenging info, just trying to understand. Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 24, 2022 Report Share Posted July 24, 2022 I have a heavy starter cable from battery -ve to bell housing, getting rid of that 'orible plaited thing. I think that's what John has. Doug Link to comment Share on other sites More sharing options...
JohnD Posted July 24, 2022 Report Share Posted July 24, 2022 On starting in particular, about 300 Amps must flow through the starter, into the block. From there, it must return to the battery, but the engine, is isolated by rubber mounting blocks. So is the gearbox, and the differential, even the rear suspension uprights! Even connected to the chassis still leaves the rubber discs between that and the body to pass. All that is left to carry that enormous current are routes like the handbrake cable, choke cable, even accelerator cable, possibly the bolts that fasten body to chassis. Triumph knew but fitted that cheapskate mesh cable that rotted away quickly. A length of starter cable, run as described, provides a low resistance pathway, able to carry that current, and easily the usual running demand. BOLT one end to the block, ensuring clean bare metal on both faces, not merely the threads of the bolt. Ditto the bulkhead fastening. John Link to comment Share on other sites More sharing options...
daverclasper Posted July 24, 2022 Report Share Posted July 24, 2022 Ah, so like Doug has said?. Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 24, 2022 Report Share Posted July 24, 2022 No no, like John has said. Doug Link to comment Share on other sites More sharing options...
NonMember Posted July 24, 2022 Report Share Posted July 24, 2022 The really important bit is to have a direct 300A cable from battery -ve to the engine block (or backplate, as that's actually what the starter motor is bolted to). It's also important to have a decent cable from battery -ve to the body. Triumph did this (on at least some models) by adding a connection to body somewhere along the length of that engine earth cable. Link to comment Share on other sites More sharing options...
daverclasper Posted July 24, 2022 Report Share Posted July 24, 2022 Thanks. I think its clear now Link to comment Share on other sites More sharing options...
ahebron Posted July 29, 2022 Report Share Posted July 29, 2022 I think I have mentioned before on here to never rely on the body/chassis as a return path for electrics on vehicles. I always try run a neutral cable to everything that needs it and bond the body or chassis. I welded studs on the back of the front indicator sidelights on the Vitesse when I found it uses the bonnet as its return. Far to many variables in our cars lives will have gone on. I even saw this on a friends 2014 Nissan pickup, the rear power outlet he fitted in the tray stopped working but gave a 12 volt reading on a meter, turns out the neutral was just to the tray and it is rubber mounted with a nice steel bolt clamping the chassis to the body. As he lives on a boat in a marina and the pickup parks on the hard it had a regular salt treatment which had corroded the mounting bolts enough so they would not allow an electrical load to pass through them. My Vitesse 6 battery neutral goes to the bulkhead lh nut side then to a starter motor bolt on the gearbox Link to comment Share on other sites More sharing options...
Colin Lindsay Posted July 29, 2022 Report Share Posted July 29, 2022 I used the TR6 cable on my GT6 to earth the engine to both body and battery terminal. I assume it worked as I never had any problems! Link to comment Share on other sites More sharing options...
JohnD Posted July 29, 2022 Report Share Posted July 29, 2022 I was interested recently by a post on the Ford Transit page of Facebook. Someone was worried about the earth cable fitted to his Transit, and showed a picture - it was an identical manky bit of wire mesh to that fitted by Triumph, fifty years ago! Both Triumph and Ford were/are known to be penny pinchers! John Link to comment Share on other sites More sharing options...
daverclasper Posted July 29, 2022 Report Share Posted July 29, 2022 3 hours ago, JohnD said: I was interested recently by a post on the Ford Transit page of Facebook. Someone was worried about the earth cable fitted to his Transit, and showed a picture - it was an identical manky bit of wire mesh to that fitted by Triumph, fifty years ago! Both Triumph and Ford were/are known to be penny pinchers! Good, interesting stuff. My car seems good on original set up (though has I think, been, sensibly/originally style restored?). and I have cleaned leccy connections if needed and preserved in grease. Apart from a couple of duff, modern condensers, failed voltage regulator, on the car, when I bought it, and one rear bulb, has been dead reliable. Bought car 9 years ago. Parked on street, under a cover. Battery earth is, about a 2cm braided cable to bulkhead (which I covered white grease yonks ago). Will strengthen the earth system with above belts and braces advice. (this is defiantly not the "must have" stuff, that I avoid, I imagine?). Cheers. Link to comment Share on other sites More sharing options...
DanMi Posted July 30, 2022 Report Share Posted July 30, 2022 16 hours ago, JohnD said: I was interested recently by a post on the Ford Transit page of Facebook. Someone was worried about the earth cable fitted to his Transit, and showed a picture - it was an identical manky bit of wire mesh to that fitted by Triumph, fifty years ago! Both Triumph and Ford were/are known to be penny pinchers! John To be fair the cars had a design life of about 10-15 years, so really that manky bit of cable was perfectly adequate, just not up to still being used 40-50 years later Link to comment Share on other sites More sharing options...
Wagger Posted July 30, 2022 Report Share Posted July 30, 2022 I have a reel of flat tinned copper woven and plaited that was used on flight simulators. I use that for this purpose and it also makes good exhaust hangers. Link to comment Share on other sites More sharing options...
Peter Truman Posted July 30, 2022 Report Share Posted July 30, 2022 On my Vitesse I have two earths between bulkhead and engine one each side bolted to the bell housing bolts. There 9in long 1in wide flat woven tinned copper, their from 4MW variable speed motors on big big pumps there’s around 200 such straps in them motors I took a few ones that were being replaced. What I probably need to do is put a couple of earth straps between the front and rear body tubs as I currently rely on the chassis bolts & the battery is in the boot/trunk. Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 30, 2022 Report Share Posted July 30, 2022 yes a good earth bonding to link everything to everything and back to the battery does make a good belt and braces result to the old rusty hope wing and a prayer Pete Link to comment Share on other sites More sharing options...
Peter Truman Posted July 30, 2022 Report Share Posted July 30, 2022 It’s Aus no rust! But get the sentiment! Link to comment Share on other sites More sharing options...
JohnD Posted July 30, 2022 Report Share Posted July 30, 2022 1 hour ago, Peter Truman said: It’s Aus no rust! But get the sentiment! What??? Annual rainfall, Victoria state, Australia - 2000mm Annual rainfall, UK (average) 1200mm So no rust, mate? Why? Link to comment Share on other sites More sharing options...
Wagger Posted July 30, 2022 Report Share Posted July 30, 2022 Same reason as we have had no rain and poor Colin L has had a deluge. Only 400 miles of latitude. We have needed a Naitonal Grid for water since my first drought experience in 1959. Went to primary school with a short sleeved shirt and shorts for a whole term. It did'nt rain until October half term. Two years before that, we had almost 1 in dia hailstones in June 1957 at Warninglid in Sussex. Extreme weather ain't new, it's just a bit more extreme. Still waiting for the solution to the imbalance of useable water. On an island surrounded by it! Link to comment Share on other sites More sharing options...
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