jonathantennantbtinternet Posted May 3, 2019 Share Posted May 3, 2019 I'm on my third k engined 7 and the first two I had no issues but my Superlight ...... So I'm wondering what everyone else has done to prevent this .Will doing the relay mod solve the problem ?Has anyone fitted a Brice starter ?Has anyone heat shielded the solonoid, if so with what. Advice and tips please much apreciated . Thanks Link to comment Share on other sites More sharing options...
SM25T Posted May 3, 2019 Share Posted May 3, 2019 There must be more threads on these pages about this than any other subject. Have you searched ? Link to comment Share on other sites More sharing options...
CageyH Posted May 3, 2019 Share Posted May 3, 2019 Personally, I don’t think the relay mod is required, unless the relay in the MFRU is failing.The most likely reason is the small cable feeding the solenoid has been cooked, and is crispy. I fed a new wire in, which I protected with a thermal sleeve, and added a thermal blanket wrapped around my starter. Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 3, 2019 Share Posted May 3, 2019 Will doing the relay mod solve the problem ?...Personally, I don’t think the relay mod is required, unless the relay in the MFRU is failing....The click is the final common path of a wide range of problems. As Ian observes there's a vast amount on these in the archives.And one of the things you'll spot in that trawl is the reluctance of some Members to seek a diagnosis before the treatment. Fortunately we have experts who will help. :-)Jonathan Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 3, 2019 Share Posted May 3, 2019 The most likely reason is the small cable feeding the solenoid has been cooked, and is crispy.How do you think that affects the conductivity of the metal wire?Jonathan Link to comment Share on other sites More sharing options...
SM25T Posted May 3, 2019 Share Posted May 3, 2019 It fatigues after becoming brittle with heat, then snaps ... unseen... inside the insulation. Link to comment Share on other sites More sharing options...
CageyH Posted May 3, 2019 Share Posted May 3, 2019 The metal is also heavily oxidised when cooked, and no longer conducts very well. I changed out the cooked wire, and no longer had a problem. I did not touch anything else.What conclusion does this lead you to? Link to comment Share on other sites More sharing options...
Bricol Posted May 3, 2019 Share Posted May 3, 2019 Standard starter, original power cables, new cable and relay arrangement from ignition switch, completely by-passing the Caterham wiring - no wasted clicks since :) Link to comment Share on other sites More sharing options...
shn7 Posted May 3, 2019 Share Posted May 3, 2019 As JK has said there are many causes all resulting in insufficient current getting to the solenoid/starter. In one case I had an FIA switch the was failing internally. Other causes are optional. Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 4, 2019 Share Posted May 4, 2019 It fatigues after becoming brittle with heat, then snaps ... unseen... inside the insulation....The metal is also heavily oxidised when cooked, and no longer conducts very well. I changed out the cooked wire, and no longer had a problem. I did not touch anything else.What conclusion does this lead you to?...Thanks.I'm very surprised that the metal fails in that way. I'd encourage everyone if possible to do the reverse test once a fix is found: restore the suspected problem and see if the fault returns. That's a hassle but there is a reason.The click is a final common path as agreed above. The big list of problems includes batteries that aren't quite up to it and bad connections. It's almost impossible to fix anything without breaking and making connections along the way. And the click doesn't necessarily have a single cause: a poor connection with a wire that's too long and a tired solenoid and a battery that needs to meet its maker can all contribute. And if any of those are there it's a good idea to fix them in a warm dry garage rather than at the roadside.But I wouldn't refit a broken wire just to make the point! ;-)Jonathan Link to comment Share on other sites More sharing options...
anthony1956 Posted May 14, 2019 Share Posted May 14, 2019 Click of death relates to fried metal, usually wires but also brushes inside. Long list of things all somewhere in the archives ; good luck with that ;-) yes to Brise, heat protective covers x 2, wires routes away from primaries, I keep spare made up solenoid wires. I had the relay mod until recently when it was removed as not required. I think the principal defence is after all the dreadful cod experiences, my associated (If mild) ptsd (really, but another story in the archives) is hypervigilance for initial symptoms. What I wish I had known before it all happened ... pre season check voltage conductivity (look for voltage drops) in related wires. One was only 7v and immediate start with fresh wire. The only one I cannot think how one would check is the internal brushes’ falling to bits owing to vibration and heat over some years. Also one of my starters had a wire connect out of sight round the back and it disintegrated, no cod just instant failure, when resoldered (one of those huge blow torch type solders) it has been fine, except I have replaced it with the Brise. Edit to add the most obvious sign of cod (as opposed to duff battery etc) is that the car won’t start when hot, and then starts after being allowed to cool. When really advanced, car can be push started, but then appears no different from dud battery, until battery test shows the battery is ok. Anthony Link to comment Share on other sites More sharing options...
jonathantennantbtinternet Posted May 14, 2019 Author Share Posted May 14, 2019 So this is what I did. Replaced the existing 2mm cable from the relay to solenoid for 3 mm. The old cable insulation was burnt by the primaries. The new 3 mm cable protected by heat shield cable sheath. All old connectors replaced with new soldered connections. Primaries wrapped with heat tape and starter . Hope that should solve the issue Link to comment Share on other sites More sharing options...
anthony1956 Posted May 14, 2019 Share Posted May 14, 2019 or slow it down ;-) (the heatsoak I mean, not the car) Link to comment Share on other sites More sharing options...
revilla Posted May 15, 2019 Share Posted May 15, 2019 Soldering the connectors is not a good idea. There's a good reason why the original connectors are always crimped. Solder wicks into the wire and bonds the strands together and the resulting rigid portion becomes very brittle, and tends to fracture close to the connector when fatigued by vibration. Soldering should only really be used for joints which are rigidly mechanically supported, not free-standing wires. Proper F-type crimped terminals are the way to go (NOT those horrible pre-insulated crimps with the hard red / yellow / blue insulation you get in Halfords and the likes). When done properly the pressure from the crimping process actually forms minute cold welds which prevent oxide layers forming and if you try to pull one off, the wire will often snap before the crimp comes loose. The tool costs a few pounds initially but with a bit of practice you can produce professional standard crimped joints a lot quicker / easier / neater than soldered joints. Link to comment Share on other sites More sharing options...
revilla Posted May 15, 2019 Share Posted May 15, 2019 This is what I did:The total length of wiring between the point where power is taken off the main battery cable and the solenoid must be about 10cm. I originally replaced the solenoid wire as above and added an additional relay but if you look with an oscilloscope, you still lose a significant voltage around the system doing it that way due to the length of cabling involved. Interestingly I found that the voltage drop along a length of 3mm2 cable under the load of the solenoid was quite a bit higher than the value I calculated from the resistance figures given for the cable, so I think these need to be taken with a pinch of salt sometimes. Transiently the solenoid current can peak at well over 20A.Measuring with a multimeter isn't good as if it's working the "pull-in" phase when the solenoid draws the full current only lasts for milliseconds. For testing purposes I "knobbled" a starter internally to stop the motor engaging, leaving it in pull-in mode for long enough to get good measurements.Doing it this way, the voltage at the solenoid is within a very small fraction of a volt of the battery voltage.There were some concerns when I first did it that heat could affect the relay etc. but it's been there for about 2 years now and all looks as fresh as the day it was fitted.The original solenoid wire now connects to the free terminal you can see on the relay in the top picture rather than directly to the solenoid. No modification to the wire or connector needed. The difference is that it is only required to carry milliamps now to operate the relay coil; it really doesn't matter how much it gets fried and oxidised, so long as there's one strand intact it will work fine every time. Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 15, 2019 Share Posted May 15, 2019 Excellent.Please could you add a bit more detail about the fixing of the relay: is that one point onto an existing fastener so that no other fettling was needed?ThanksJonathan Link to comment Share on other sites More sharing options...
revilla Posted May 15, 2019 Share Posted May 15, 2019 Yes I used the existing starter casing studs, one to mount the relay, one for a ring terminal for the earth side of the relay coil. The other side of the coil is driven by the old solenoid wire. The relay switches directly from the main battery feed to the motor into the solenoid via a fuse for safety (just in case anything came loose really). I put the ring terminal on the main battery terminal underneath the inner locking nut, so none of it comes loose when you remove the outer nut and the battery and alternator cables. It's all sort of "part of the starter motor" now. Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 15, 2019 Share Posted May 15, 2019 ThanksJonathan Link to comment Share on other sites More sharing options...
simonhar Posted May 26, 2019 Share Posted May 26, 2019 So my 17 yr old 1.6 K has occasionally had this issue when hot,it is getting more frequent but always solved by rocking the car in gear. The grey?red wire to the solenoid has at some point come in contact with the exhaust and the insulation is damaged.Given the low mileage of 30 k can I assume that the solenoid is alright but when hot needs a higher current; by rocking the car it moved the teeth in the drive away from a contact point allowing it to gain some momentum before making contact with s tooth in the drive. If this makes sense doing the wiring modification will help? Link to comment Share on other sites More sharing options...
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