Chris A Posted September 11, 2021 Report Share Posted September 11, 2021 You're beginning to worry me now, in future I'll drive with the fire extinguisher on my lap ! Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 11, 2021 Author Report Share Posted September 11, 2021 Wayyyyy back - yes, that far back - I converted a positive earth Herald to negative earth. "Don't believe any of the stories about the fan now sucking instead of blowing" ran the article "but your wiper motor will now spin in the reverse direction. After years of use it has bedded in by running in one direction, so in order to get it back to where it should be and running smoothly again, change round the wires at the wiper motor." Ever done that? Nothing happens for a minute then you see the smoke coming up from under the dashboard. So: after sulking for a bit I removed the entire loom, labelling the connections as I did so. The loom was repaired and the melted sections replaced. Then I put it back, exactly as before. It melted straight away, exactly as before. Now you know why I'm wary of ANYTHING to do with the wiper circuit, and will debate for hours before going near it. Link to comment Share on other sites More sharing options...
NonMember Posted September 11, 2021 Report Share Posted September 11, 2021 1 hour ago, Colin Lindsay said: "but your wiper motor will now spin in the reverse direction. I don't know where you read that but the author of the article was an idiot who had never looked at a Lucas wiper motor. It cannot have its wires swapped, as you found out the hard way, and is not a permanent magnet motor anyway so will NOT run backwards if the polarity is swapped. Triumph did not change the wiper motor or any part of the wiper circuit when they changed the Herald from positive to negative earth. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 12, 2021 Author Report Share Posted September 12, 2021 11 hours ago, NonMember said: I don't know where you read that but the author of the article was an idiot I think I might have determined that by now. It was part of a type-written set of 'how-to' instructions that came in a huge pile of paperwork in the car, so no idea where it originated and it's since been safely disposed of. It also included gems like 'the bulbs will now work back to front so may not be as bright as they were originally; consider a new set of negative earth bulbs all round' and there as also a paragraph on swapping the horn terminals around so that they would be as loud as before. Back in the day when my entire tool kit was a woodsaw, a hammer and a spanner, that sounded wonderfully knowledgeable. 1 Link to comment Share on other sites More sharing options...
NonMember Posted September 12, 2021 Report Share Posted September 12, 2021 28 minutes ago, Colin Lindsay said: It also included gems like 'the bulbs will now work back to front so may not be as bright as they were originally; Are you sure it wasn't published on April 1st? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 12, 2021 Author Report Share Posted September 12, 2021 2 hours ago, NonMember said: Are you sure it wasn't published on April 1st? It may well have been. Seemed like a print-out from a black and white Club Magazine of some description... but after the harm it did to my loom it went in the bin, I remember pouring water over it to soak it so that it couldn't be dug out and reused at a later date... Link to comment Share on other sites More sharing options...
Chris A Posted September 12, 2021 Report Share Posted September 12, 2021 3 hours ago, Colin Lindsay said: the bulbs will now work back to front so may not be as bright as they were originally; Surely if they were working back to front wouldn't they suck in light? 😵 Link to comment Share on other sites More sharing options...
dougbgt6 Posted September 12, 2021 Report Share Posted September 12, 2021 2 hours ago, Chris A said: Surely if they were working back to front wouldn't they suck in light? 😵 Dumbledore gave Ron Wheasley a device that does that in the Deathly Hallows. Doug Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 12, 2021 Author Report Share Posted September 12, 2021 35 minutes ago, Chris A said: Surely if they were working back to front wouldn't they suck in light? 😵 I think I worked with people who had that sort of personality. Link to comment Share on other sites More sharing options...
PeteH Posted September 12, 2021 Report Share Posted September 12, 2021 9 hours ago, Colin Lindsay said: It also included gems like 'the bulbs will now work back to front so may not be as bright as they were originally; consider a new set of negative earth bulbs all round' and there as also a paragraph on swapping the horn terminals around so that they would be as loud as before. That want`s fileing under the same heading as "A Long Stand", "bucket of 1/2" holes" (or steam), Tartan Paint?. Every Aprentice fell for one or the other. Pete Link to comment Share on other sites More sharing options...
Badwolf Posted September 12, 2021 Report Share Posted September 12, 2021 Ok. I am going to lead myself wide open to abuse and ridicule here, but reading the comments about battery terminal reversal (+ earth to - earth) got me thinking...which as you all know is dangerous. At a show a couple of years ago, I bought one of those battery dis-car-nect thingies, which sat around in the spares box for some time. Then, when I did my fuse box upgrade I finally fitted it... to the negative terminal of the battery, as that's where I had seen others fitted and also on some yootoob vids. Now, all this talk of fires etc got me thinking that I should have fitted it to the positive terminal so that it isolates the battery from the car totally. How I have connected it up, leaves the danger of reconnecting the battery by accident with a spanner etc from body to battery earth, and before someone says it, yes, I know that I should totally disconnect and remove it before doing any work!!!! Is mine wrong or right?? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 12, 2021 Author Report Share Posted September 12, 2021 Rimmer Brothers video says negative, NEVER the positive side. Link to comment Share on other sites More sharing options...
Badwolf Posted September 12, 2021 Report Share Posted September 12, 2021 Why?? Link to comment Share on other sites More sharing options...
PeteH Posted September 12, 2021 Report Share Posted September 12, 2021 Strangely, the one I had, would have been to large for the Negative terminal.? Pete Link to comment Share on other sites More sharing options...
NonMember Posted September 12, 2021 Report Share Posted September 12, 2021 1 hour ago, Badwolf said: How I have connected it up, leaves the danger of reconnecting the battery by accident with a spanner etc from body to battery earth, On the contrary, that is precisely why you are recommended always to fit the discarnect in the earth (negative) lead. With the battery positive disconnected but the earth still there, you could drop a spanner on the battery and, if unlucky, have it land on both the battery's positive terminal and the bodywork. This forms a dead short from battery +ve, through the spanner, then the body, then the earth strap, to the battery negative. Shorted battery, huge current, bang! Now suppose it's the earth lead you've disconnected. Dropping that same spanner now connects the car's main power to earth... but there's no power on it because the battery is already disconnected from the car's earth. The battery negative terminal sits at -12V quite calmly and without any issue. Were you instead to drop the spanner on the -ve post to body, all you're doing is re-connecting the normal circuit, so again all's well. 1 Link to comment Share on other sites More sharing options...
Badwolf Posted September 12, 2021 Report Share Posted September 12, 2021 Aahhh!!! Link to comment Share on other sites More sharing options...
Chris A Posted September 13, 2021 Report Share Posted September 13, 2021 14 hours ago, Badwolf said: Aahhh!!! I'll double that ! I learn something new every day here, mind you it isn't difficult in my case. Link to comment Share on other sites More sharing options...
Chris A Posted September 13, 2021 Report Share Posted September 13, 2021 So couldn't simply putting a piece of fabric or cardboard on the top of the battery offer the same safety when working under the bonnet? I think I'll make myself a designer battery protection cover from an old shoe box lid. NO! You can't start quoting 'The shoe box sketch' 1 Link to comment Share on other sites More sharing options...
DVD3500 Posted September 13, 2021 Report Share Posted September 13, 2021 17 minutes ago, Chris A said: So couldn't simply putting a piece of fabric or cardboard on the top of the battery offer the same safety when working under the bonnet? Way too practical and simple... I need a 3D printed, one off, hand-sanded cover made of extruded bamboo ... 😄 Link to comment Share on other sites More sharing options...
trigolf Posted September 13, 2021 Report Share Posted September 13, 2021 17 hours ago, NonMember said: With the battery positive disconnected but the earth still there, you could drop a spanner on the battery and, if unlucky, have it land on both the battery's positive terminal and the bodywork. This forms a dead short from battery +ve, through the spanner, then the body, then the earth strap, to the battery negative. Shorted battery, huge current, bang! My late father had a one ended (previously 2 ended) spanner that a workmate had dropped across the batt terminals of an aircraft 'Trolley Accumulator' - basically a bank of 100AH batts in a trolley to start a/c on the ground. When the spanner shorted the batt out there was indeed a huge bang and one end of the spanner basically vapourised ! 😕 Gav Link to comment Share on other sites More sharing options...
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