KiwiTR6 Posted October 20, 2019 Report Share Posted October 20, 2019 (edited) Now that my new alternator is installed I have been checking the charging system to ensure all is as it should be. In hindsight I should have done this before changing the alternator but I would have gone ahead with that anyway just for peace of mind. First up, I found that I had 14.2V at the alternator but a drop of nearly 1.0V at the battery (reading 13.2V). Time to start looking. Checking the heavy brown wire at the connector to the starter lead I quickly found where part of the voltage drop was - the clear rubber terminal boot had folded over and was preventing full contact. Fixed that problem and I now had a 0.5V drop to find. I had a sneaking suspicion that the terminal block moulded to the starter lead (what a horrid idea that is) could be suspect, so I made up a jumper lead and connected the heavy brown wire direct to the battery. Voltage drop now down to 0.14V and problem solved. Hoping this experience may be of help to other owners at some point. Edited October 20, 2019 by KiwiTR6 Copied earlier post in error. Quote Link to post Share on other sites
Mike C Posted October 20, 2019 Report Share Posted October 20, 2019 When you posted earlier today on another post I was going to add that voltage drop and overheating was the reason I limited my alternator upgrade to reworking the existing Lucas to 45 amps. I looked at modifying 80+ amp GM alternators and decided that I was getting in the realm of putting welding level currents through my 50 year old wiring loom. In particular in my 69 CP the current goes through the dash loom to the ammeter -which is a good incentive to let sleeping dogs lie. I assume that you are confident that your wiring can safely handle your new alternator's output. Quote Link to post Share on other sites
RobH Posted October 20, 2019 Report Share Posted October 20, 2019 Putting on a bigger alternator does not in itself increase the current. The current drawn is determined by the loads not the alternator, so if you haven't changed anything else then going from a 45A to an 80A one will make no difference to the current drawn - it's just that the bigger one will be capable of supplying the higher current if asked to. If you do install beefy accessories than then wiring for those should be suitable for the current they draw. Quote Link to post Share on other sites
Mike C Posted October 20, 2019 Report Share Posted October 20, 2019 I'm talking about charging current after a difficult starting episode- the current that goes to the +40 or so mark on the ammeter. Quote Link to post Share on other sites
RogerH Posted October 20, 2019 Report Share Posted October 20, 2019 (edited) 17 hours ago, KiwiTR6 said: Now that my new alternator is installed I have been checking the charging system to ensure all is as it should be. In hindsight I should have done this before changing the alternator but I would have gone ahead with that anyway just for peace of mind. First up, I found that I had 14.2V at the alternator but a drop of nearly 1.0V at the battery (reading 13.2V). Time to start looking. Checking the heavy brown wire at the connector to the starter lead I quickly found where part of the voltage drop was - the clear rubber terminal boot had folded over and was preventing full contact. Fixed that problem and I now had a 0.5V drop to find. I had a sneaking suspicion that the terminal block moulded to the starter lead (what a horrid idea that is) could be suspect, so I made up a jumper lead and connected the heavy brown wire direct to the battery. Voltage drop now down to 0.14V and problem solved. Hoping this experience may be of help to other owners at some point. Hi Gavin, what are the black boots for over the orange wires. I am looking for something to go over the Lucas bullet connectors (single and double) Hi Mike, I would be amazed if you got near 40amps charge after a difficult start. 30 amps probably for a few seconds then reducing to 20, 10, 5 over a few minutes and staying 5 until it is happy. Roger Edited October 20, 2019 by RogerH Quote Link to post Share on other sites
john.r.davies Posted October 20, 2019 Report Share Posted October 20, 2019 Fuse holders, Roger. Quote Link to post Share on other sites
Mike C Posted October 20, 2019 Report Share Posted October 20, 2019 I know it's only for a short period of initial charge but I just don't want to smell cotton/rubber insulation burning behind the dashboard. Quote Link to post Share on other sites
KiwiTR6 Posted October 20, 2019 Author Report Share Posted October 20, 2019 8 hours ago, RogerH said: Hi Alan, what are the black boots for over the orange wires. I am looking for something to go over the Lucas bullet connectors (single and double) Hi Mike, I would be amazed if you got near 40amps charge after a difficult start. 30 amps probably for a few seconds then reducing to 20, 10, 5 over a few minutes and staying 5 until it is happy. Roger Hi Roger. Yes they are in-line fuse holders as John says, one on the main supply to the Bosch fuel pump and the other supplying power to my ex Audi brake vacuum pump, both direct from the battery. In due course these will be replaced with a supplementary fuse box but they work for the time being. Cheers Quote Link to post Share on other sites
KiwiTR6 Posted October 20, 2019 Author Report Share Posted October 20, 2019 (edited) 12 hours ago, Mike C said: When you posted earlier today on another post I was going to add that voltage drop and overheating was the reason I limited my alternator upgrade to reworking the existing Lucas to 45 amps. I looked at modifying 80+ amp GM alternators and decided that I was getting in the realm of putting welding level currents through my 50 year old wiring loom. In particular in my 69 CP the current goes through the dash loom to the ammeter -which is a good incentive to let sleeping dogs lie. I assume that you are confident that your wiring can safely handle your new alternator's output. Hi Mike. From what I've read this particular 70A alternator is a common upgrade for the car. It bolts straight up to the existing mounts, the only tricky part is modifying the existing pulley (as I did rather than looking for something else suitable) to get the alignment spot on, and connecting the wiring which are studs rather than terminals. The loom is a Moss replacement, so no cotton/rubber insulation in sight! Door cards off and mirrors on today - a much more daunting task.... Gavin Edited October 20, 2019 by KiwiTR6 Clarification Quote Link to post Share on other sites
Mike C Posted October 20, 2019 Report Share Posted October 20, 2019 And I just checked - you have a 73 TR which should have a voltmeter and a much more direct path between the battery and alternator. I agree with you on the door cards and mirrors, visible work on the body is far more daunting and less forgiving of any mistakes. Quote Link to post Share on other sites
KiwiTR6 Posted October 20, 2019 Author Report Share Posted October 20, 2019 32 minutes ago, Mike C said: And I just checked - you have a 73 TR which should have a voltmeter and a much more direct path between the battery and alternator. I agree with you on the door cards and mirrors, visible work on the body is far more daunting and less forgiving of any mistakes. Yes a voltmeter that reads 1.0V low, but I'll get that sorted in time. Almost direct as you say, but it's where it connects to the starter lead that I was losing 0.5V. Its a horrid connector block moulded to the lead wire, I'll be removing all connections from that point and routing them via a supplementary fuse box direct to the battery +ve with the heavy alternator supply wire also going direct to the same point. I've changed that temporarily at this stage with a short jumper lead. Quote Link to post Share on other sites
Mike C Posted October 20, 2019 Report Share Posted October 20, 2019 And I'd solder every connection I can, if voltage drop looks like being a problem I'd even solder wire tails to be fitted to screwed sockets. Quote Link to post Share on other sites
Charlie D Posted October 21, 2019 Report Share Posted October 21, 2019 Mike, I was always told NOT to tin the ends of wires that go into screw connectors. Apparently over time the solder will “Creep” sideways under the compression of the screw and you end up with a loose joint. Well… That’s what I was told as an apprentice. Charlie. Quote Link to post Share on other sites
Andy Moltu Posted October 21, 2019 Report Share Posted October 21, 2019 Crimp/compression joints would not normally be soldered Quote Link to post Share on other sites
Waldi Posted October 21, 2019 Report Share Posted October 21, 2019 This topic (crimping versus soldering or even both) was discussed a couple of years ago. Opinions and preferences differ. I use crimping connectors, not the poor red/yellow/blue ones, but the ones that also crimp the wire isolation to the connector to it is more rigid. You need a special tool, which is more expensive (they start at around 30 euro), and also some money goes into ordering a collection of connectors and sleeve. Soldering does not hold/secure the wire Itself to the connector, and can give corrosion if not properly cleaned after soldering. And proper cleaning is difficult since the acid will suck into the isolation by the capillary action. The above is just my opinion. Waldi Quote Link to post Share on other sites
john.r.davies Posted October 21, 2019 Report Share Posted October 21, 2019 I believe that aerospace practice (Roger?) eschews soldering in favour of crimping. The reason I've been told is that solder tends to 'wick' by capillary action between the strands of the cable, stiffening the conductor away from the connection, so that fatigue and breakage is more likely. John Quote Link to post Share on other sites
RobH Posted October 21, 2019 Report Share Posted October 21, 2019 Indeed we have had that debate before. A crimp made with a proper ratchet crimp-forming tool can certainly be relied on. A crimp using one of those 'bent-tin' pliers - maybe not so much. Soldering should not cause corrosion unless you are using the wrong flux. An acid flux is definitely not the right type. Quote Link to post Share on other sites
Waldi Posted October 21, 2019 Report Share Posted October 21, 2019 Thanks Rob, the acid based flux is what I’m familiar with. No good. What flux would you recommend for electric connection soldering? Cheers, Waldi Quote Link to post Share on other sites
RogerH Posted October 21, 2019 Report Share Posted October 21, 2019 52 minutes ago, john.r.davies said: I believe that aerospace practice (Roger?) eschews soldering in favour of crimping. The reason I've been told is that solder tends to 'wick' by capillary action between the strands of the cable, stiffening the conductor away from the connection, so that fatigue and breakage is more likely. John Hi John, quite so. Aerospace have used crimped terminals for many many decades. Before they were used they were extensively tested to ensure they were as good as solder joints (regarding conductivity), Mechanically crimped joints are far superior to solder and they are easier to perform when remote from the workshop. I know you can get gas powered portable soldering irons but that doesn;t make them better. Roger Quote Link to post Share on other sites
RobH Posted October 21, 2019 Report Share Posted October 21, 2019 (edited) Its easiest to use a flux-cored solder intended for electrical work Waldi, similar to this: https://www.amazon.co.uk/Weller-40-100-Electronic-Solder-Resin/dp/B0001P1724/ref=sr_1_6?keywords=flux+cored+solder&qid=1571662665&sr=8-6 (just for illustration - you can get similar solder cheaper than that. There is a wide choice of solder both tin/lead and lead-free and some fluxes are rosin-free as well, mainly due to health concerns. Personally I stick to the old tin/lead and rosin core stuff because I know that works. Some of the lead-free stuff doesn't seem to work as well and needs higher temperatures. It may also not be fully compatible with joints on old circuits when doing repairs.) The flux is usually rosin-based, which is basically pine resin, but there are some health concerns over long-term use as the fumes are a 'sensitiser' and can cause asthma. Generally only a problem for people using it day-in day-out as part of their job. It isn't really necessary to remove the residue from that type of flux as it forms a hard varnish-like layer. If you must use a flux paste then make sure it specifically says it is for electrical work like this: https://www.amazon.co.uk/MG-Chemicals-Rosin-Flux-Paste/dp/B01MS04SO4/ref=pd_sim_328_2/259-0048478-8658313?_encoding=UTF8&pd_rd_i=B01MS04SO4&pd_rd_r=e780069f-2d9b-4488-800d-ef900833af57&pd_rd_w=FeqtD&pd_rd_wg=onZAD&pf_rd_p=e323aefa-0fb8-4e75-9bef-479c25fd70eb&pf_rd_r=FES298YG815FFKK6QWCR&psc=1&refRID=FES298YG815FFKK6QWCR. Edited October 21, 2019 by RobH Quote Link to post Share on other sites
astontr6 Posted October 21, 2019 Report Share Posted October 21, 2019 4 hours ago, Andy Moltu said: Crimp/compression joints would not normally be soldered They are if you terminate to the MOD spec for vechicle wire termination! Crimp first then solder! Bruce. Quote Link to post Share on other sites
stuart Posted October 21, 2019 Report Share Posted October 21, 2019 32 minutes ago, RogerH said: I know you can get gas powered portable soldering irons but that doesn;t make them better. Roger Oh it does they are so handy, Ive been using them since they came out in the early eighties, best Irish invention! Stuart. Quote Link to post Share on other sites
stuart Posted October 21, 2019 Report Share Posted October 21, 2019 1 minute ago, astontr6 said: They are if you terminate to the MOD spec for vechicle wire termination! Crimp first then solder! Bruce. Which is what I have been doing for the last forty odd years. Stuart. Quote Link to post Share on other sites
astontr6 Posted October 21, 2019 Report Share Posted October 21, 2019 34 minutes ago, RogerH said: Hi John, quite so. Aerospace have used crimped terminals for many many decades. Before they were used they were extensively tested to ensure they were as good as solder joints (regarding conductivity), Mechanically crimped joints are far superior to solder and they are easier to perform when remote from the workshop. I know you can get gas powered portable soldering irons but that doesn;t make them better. Roger Also Roger crimps are subject to the pull off test and the crimper should have been calibrated. Mr average, I doubt will have that level of equipment. Bruce. Quote Link to post Share on other sites
astontr6 Posted October 21, 2019 Report Share Posted October 21, 2019 4 minutes ago, stuart said: Which is what I have been doing for the last forty odd years. Stuart. So have I! Bruce. Quote Link to post Share on other sites
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