wiltsathome Posted January 2, 2021 Share Posted January 2, 2021 Can anyone tell me what this is please? It's behind the dash on my 2016 420R and I came across it whilst hunting for the indicator beeper. it gets hot and the car seems to function normally with it disconnected, although I only started it for a moment Link to comment Share on other sites More sharing options...
revilla Posted January 2, 2021 Share Posted January 2, 2021 Looks like a resistor that is normally connected across the FIA switch to absorb the alternator output if the engine is shut off using the cutoff, to prevent damage to the alternator or other equipment through voltage spikes. Link to comment Share on other sites More sharing options...
David_Long Posted January 2, 2021 Share Posted January 2, 2021 I believe it may be the 1/4 watt resistor used by the speedo electronics. I am not sure what its function is, but as a guess it is a dropper resistor for the electronic that probably works at 5V.Edit: Actually having checked it out, Im not so sure that is correct now. Link to comment Share on other sites More sharing options...
John Vine Posted January 2, 2021 Share Posted January 2, 2021 I recently asked CC the very same question. This was their reply:"The resistor [in the picture] is to prevent the alternator light on the tacho from coming on and yes it will get hot."IME it cools down again once the engine is running.The wiring diagram in the Assembly Guide shows it as: JV Link to comment Share on other sites More sharing options...
wiltsathome Posted January 3, 2021 Author Share Posted January 3, 2021 Many thanks guys, your information is much appreciated. Link to comment Share on other sites More sharing options...
ChrisC Posted January 3, 2021 Share Posted January 3, 2021 Instrument 5v reference power supply resistor is my guess. The isolator resistor is much larger and located on the back of the isolator switch. The wiring diagram is well out of date because your 2016 car will have three looms, engine, chassis and dash, where as that diagram is based on a car with just two looms (engine and chassis) and a MFU. I don't actually know when they stopped fitting MFUs but my 2011 car didn't have one. On the old diagram there used to be Resistor A and Resistor B on the chassis loom, Resistor A is 68 Ohm, and connected to the Tacho and Resistor B is 1KOhm as is the speed pulse (connected to the Speedo). The resistor in your photo is 68R so that's why I assume its the Tacho reference power supply to the auxiliary instruments. With it removed does your temperature gauge and oil pressure still work correctly?I only have the current chassis and engine wiring diagrams, and these resistors have been moved to the dash loom, so can't be 100% sure. Link to comment Share on other sites More sharing options...
revilla Posted January 3, 2021 Share Posted January 3, 2021 Yes I stand corrected, too small to be the alternator dump resistor for the cutoff switch. Afraid I'm showing my "K Series" age ... not so familiar with these new-fangled Ford-powered things! Link to comment Share on other sites More sharing options...
John Vine Posted January 3, 2021 Share Posted January 3, 2021 Re #6:The wiring diagram is well out of date... The latest text-based AG I can find is dated Feb 2015, and this still shows the power socket as per my diagram. OTOH, the latest IKEA-style AG (Edition 2.0, V1) doesn't include any wiring diagrams at all! Is that a deliberate move by CC? If so, it's not wonderfully helpful.I only have the current chassis and engine wiring diagrams...Are those the ones from the old Feb 2015 AG?JV Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 3, 2021 Member Share Posted January 3, 2021 I have a large collection of Assembly Guides, Handbooks and wiring diagrams that is available to all Members.Jonathan Link to comment Share on other sites More sharing options...
John Vine Posted January 3, 2021 Share Posted January 3, 2021 Re #9:Excellent, Jonathan -- that's why you're regarded on BC as the Club's librarian!So, here's a little test...Can you tell me the date of the latest AG that contains wiring diagrams? Re #8, they seem to have disappeared completely from the later IKEA-style ones.JV Link to comment Share on other sites More sharing options...
ChrisC Posted January 3, 2021 Share Posted January 3, 2021 They are 2019 diagrams from CC sent to me during my build to help resolve electrical issues I had. Unfortunately I don't have a full set, and they are not public domain so not mine to share. The diagrams in the 2015 (b and c) build manuals are only good for the first generation on Duratec / Sigma cars, that said in most instances that's fine. Lets face it the lights and wipers haven't changed much over the year. The problem comes with the new modules added, dash control module for example, and where the looms have been adapted to simplify production of the different models and options. Even my "standard" (non 620) dash car has a dash control module, which I have no clue what its doing. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 3, 2021 Member Share Posted January 3, 2021 "Can you tell me the date of the latest AG that contains wiring diagrams? Re #8, they seem to have disappeared completely from the later IKEA-style ones."TTBOMK that would be:ASSEMBLY GUIDE SEVEN 270, 360 and 420 plus ACADEMY Version 02.2015.cand ASSEMBLY GUIDE CATERHAM SEVEN 160 Version 08.2014But there are also some Workshop Notices and some diagrams that never appeared in Assembly Guides.Jonathan (Crossed with ChrisC's) Link to comment Share on other sites More sharing options...
ChrisC Posted January 3, 2021 Share Posted January 3, 2021 The IKEA build manuals are not all they are cracked up to be. Having just built two kits in four years, and worked on several others, the latest Duratec IKEA manual leaves a lot to be desired. When it was released I raised over 30 mistakes / observations with CC, from the manual not covering changes to front suspension, missing build steps, to swapping half way through the manual to a Sigma build and back again. I listed all of these on a blog post. Which has proven to be very popular. Link to comment Share on other sites More sharing options...
John Vine Posted January 3, 2021 Share Posted January 3, 2021 Re #11: Thanks, Chris. I wonder if CC could be persuaded to make them generally available? I also wonder what reasons they might have for not doing so?Re #12: Thanks, Jonathan. Your first AG matches the one in my set. For info, I have a slightly later 160 AG (Version 09.2015.b) if that's of interest to you.JV Link to comment Share on other sites More sharing options...
John Vine Posted January 3, 2021 Share Posted January 3, 2021 Re #13:When it was released I raised over 30 mistakes / observations with CC...Out of interest, did they respond or, at least, incorporate them in a later version? I ask as I did exactly the same thing with the 2008 AG after my R400D build. My list ran to 45 items. I never received a reply, but I did notice that, of the 28 "errors and omissions", the eventual scoreline read: fixed 16, not fixed 12.JV Link to comment Share on other sites More sharing options...
ChrisC Posted January 3, 2021 Share Posted January 3, 2021 No, not a thing. But I suspect there has been a few other priorities recently, putting manuals on the back burner. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now