Mucus72 Posted April 22, 2017 Share Posted April 22, 2017 hi POBC- I had a spin in the morning session and rolled backwards out of it. Car stalled, and I couldn't restart it. Its been that way since. It turns over but doesn't fire. I reset the inertia switch. I've checked fuel level, more than 50%. It's noisy here but I don't think that I hear the fuel pump kick in. Wondering if it's that or immobiliser. Took battery negative off to see if this may reset something. Its a 420R. Wondering if it's a fuse too. I've reseated them but still no joy. Does anyone know which fuse to check please. Or general help!!!thanksmarcus Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted April 22, 2017 Member Share Posted April 22, 2017 I'll dig out the fuse arrangement. You need fuel pump and ECU at least.Do you have breakdown cover: they're used to being called to locations just outside tracks!Jonathan Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted April 22, 2017 Member Share Posted April 22, 2017 Do either of these match your fuse layout?Jonathan Link to comment Share on other sites More sharing options...
mossy7 Posted April 22, 2017 Share Posted April 22, 2017 Duplicated another comment. Ignore Link to comment Share on other sites More sharing options...
Mucus72 Posted April 22, 2017 Author Share Posted April 22, 2017 Thanks for help guys. Traced to fuel pump fuse. 7.5A blown I guess when traveling backwards at 50! I'm back on track. Phew!! Link to comment Share on other sites More sharing options...
SM25T Posted April 22, 2017 Share Posted April 22, 2017 That's a relief. Link to comment Share on other sites More sharing options...
tomwood Posted April 22, 2017 Share Posted April 22, 2017 Glad you got it sorted. Interestingly the exact same thing happened to another Duratec caterham at the last track day I did last year. I wonder what it is about spinning it and going backwards which causes the fuel pup fuse to blow? Link to comment Share on other sites More sharing options...
Mucus72 Posted April 23, 2017 Author Share Posted April 23, 2017 That is interesting Tom. I don't know. At a guess I'd say that the fuel pump when suddenly confronted with the car rotating 180 degrees reaches its max load? But I have spun many times in my old K series on tracks and never had this problem. Also this one yesterday was really innocuous. Coming out of the hairpin Tarzan, 3rd gear on a very damp but drying track, searching for grip, one gear higher than normal, and on a wide, wet line. Sudden loss of grip when crossing the normal dry line on wide exit and bam, couldn't catch it. So it wasn't a really fast spin. The only other notable point is that I didnt dip the clutch in time to stop the engine stalling, but I was close, just missed it. Link to comment Share on other sites More sharing options...
Mucus72 Posted April 23, 2017 Author Share Posted April 23, 2017 And for JK, some detail on the fuse. It was fuse F in your diagram - very useful thank you. Its in the "Fuel pump relay" cluster of fuses, but the diagram to the left calls out F as "Instrument lights". It may well have a dual purpose. My instruments themselves were working, but sadly I didn't notice whether either dial or dashboard switch lines were not working.One of my mates yesterday questioned why I didn't have a fuse "grabber" or whatever they are called. The little plastic tongs that make life really easy to extract the fuses. Its a really good point. Caterham should supply one clipped into the fuse area. Maybe its a weight reduction thing?! Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted April 23, 2017 Member Share Posted April 23, 2017 Its in the "Fuel pump relay" cluster of fuses, but the diagram to the left calls out F as "Instrument lights". It may well have a dual purpose.That sounds unlikely... we probably still don't have the right layout yet. Please could you check your Assembly Guide and Handbook when convenient.One of my mates yesterday questioned why I didn't have a fuse "grabber" or whatever they are called. The little plastic tongs that make life really easy to extract the fuses. Its a really good point. Caterham should supply one clipped into the fuse area. Maybe its a weight reduction thing?!Anyone thinking about fuses might also want to consider: Fuses that show a little light when they've failed. Resettable circuit breakers rather than fuses.Those are both available for blade fuses and probably other formats.Jonathan Link to comment Share on other sites More sharing options...
John Vine Posted April 23, 2017 Share Posted April 23, 2017 Glad to hear you got going again.Apart from the puzzle over F vs D fuse labels, the fuel pump usually has a 15A fuse rather than 7.5A. So, another little puzzle.JV Link to comment Share on other sites More sharing options...
ChrisC Posted April 23, 2017 Share Posted April 23, 2017 I may be wrong, but didn't The guy that does the R500 blog have a breakdown early on when the 7.5 fuse blow. It's was something to do with the earth on the calliper from memory. Might be worth checking out. Link to comment Share on other sites More sharing options...
ChrisC Posted April 23, 2017 Share Posted April 23, 2017 Found it http://www.caterhamr500.co.uk/2014/08/raceco-exhaust-fitting-and-noise-tests.htmlit was indicators, so I guess unrelated, but strange how what seems like unrelated fuses can knock out a Duratec. Link to comment Share on other sites More sharing options...
Mucus72 Posted April 24, 2017 Author Share Posted April 24, 2017 I've been looking into this a little further Chris and POBC. I got the fuse diagram from my assembly guide and fuse F (number 6 from top) blew, rated at 7.5A and called out as RHS Tail Light.Another fuse, fuse M, rated at 15A is the fuel pump.However, that was fine, and the fuel pump was NOT whirring up until fuse F was replaced.Does anyone with any knowledge of things electrical know why this is the case. Is it just me that thinks that its also weird (related?) that the fuel pump is very near the RHS rear tail light physically? Link to comment Share on other sites More sharing options...
Stridey Posted April 24, 2017 Share Posted April 24, 2017 I'd be tempted to take the M fuse out and see if the RHS light worked? Link to comment Share on other sites More sharing options...
ChrisC Posted April 24, 2017 Share Posted April 24, 2017 Agreed - take out F and see if anything else stops working, and take out M and see what stops. I don't think it's weird, I think it's a shame changes are made and the documentation given to the owners / customers is not updated. I have posted before that there are wires in my old Sigma cars loom that aren't in the wiring diagrams, and you car has CAN bus instruments, but that isn't shown in the wiring diagrams either. At this rate your going to have the complete list of 420R fuses mapped Marcus, but don't publish it, sell it back to Caterham :-) Link to comment Share on other sites More sharing options...
John Vine Posted April 24, 2017 Share Posted April 24, 2017 Good lateral thinking, that man!If the fuses/circuits are indeed transposed, I can see why the 7.5 A fuse blew. It would need to be 15A.JV Link to comment Share on other sites More sharing options...
JNC Posted April 24, 2017 Share Posted April 24, 2017 Shoot me if I'm wrong ! Doesn't the Duratec fail safe when a fuse blows ? , the ECU see's a fault so fails safe ! ,until the fuse is replaced and the fault rectified the engine won't start. In this case the light fuse was replaced the ECU see's no fault and the fuel pump starts .I know if the speedo sensor fails it can blow a fuse and won't start until it's replaced . Link to comment Share on other sites More sharing options...
John Vine Posted April 24, 2017 Share Posted April 24, 2017 Good grief, does it really? I certainly hope not as that could mean a potential disaster if a fuse (like a rear lamp) blew during an overtake!JV Link to comment Share on other sites More sharing options...
JNC Posted April 24, 2017 Share Posted April 24, 2017 I think the ECU can't differentiate from a simple lamp or a engine control sensor ! Thus fail safe .I always carry a selection of fuses . Link to comment Share on other sites More sharing options...
John Vine Posted April 24, 2017 Share Posted April 24, 2017 I got the fuse diagram from my assembly guide and fuse F (number 6 from top) blew, rated at 7.5A and called out as RHS Tail Light.Another fuse, fuse M, rated at 15A is the fuel pump.A thought...Can you explore the back of fuses F and M and tell us what wires you find there? That may give us a clue as to what's going on.JV Link to comment Share on other sites More sharing options...
Mucus72 Posted April 24, 2017 Author Share Posted April 24, 2017 Let me do a transposition check when I get home first and if it all goes to pot then the "ECU fail safe" scenario may be in operation. But as above, that would be potentially catastrophic....Will report back gents. Link to comment Share on other sites More sharing options...
Dr Slotter Posted April 24, 2017 Share Posted April 24, 2017 In your searching through the archives did you come across this thread?https://www.lotus7.club/forum/techtalk/fuse-identification-2010-superlight-r400-stack-dashIf the fusebox layout has another variant, it'd be useful to know. Link to comment Share on other sites More sharing options...
Mucus72 Posted April 24, 2017 Author Share Posted April 24, 2017 Hi Tom, hope you are well? Thanks for fishing that thread out - no like a gormless idiot having a panic on track, I just did the unthinkable (actually sorry JK!) and posted a net new thread.So that link in the older thread to teh diagram to print out with the 50% of fuses reversed is, I think what I have. Did you take a copy of the file and if so could you upload somewhere and link to it please?ThanksMarcus Link to comment Share on other sites More sharing options...
Mucus72 Posted April 24, 2017 Author Share Posted April 24, 2017 I need to double check in the morning though, can't get access to the garage at the moment. Link to comment Share on other sites More sharing options...
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