Donncha 13 Posted June 24, 2023 My Temperature guage goes to the red and fuel guage goes more or less straight to full even though it is not full when driving. The car was off the road with two years any ideas on these issues ? Quote Share this post Link to post Share on other sites
Tigdlo 26 Posted June 25, 2023 I would say that it’s either a bad earth to the gauges, or the voltage control unit (little tin box on back of gauge cluster) has packed up. Quote Share this post Link to post Share on other sites
sheffieldcortinacentre 610 Posted June 25, 2023 As it's effecting both I'd say as above feed or earth to voltage regulator on back of clocks. Something is earthing them both. Quote Share this post Link to post Share on other sites
Donncha 13 Posted June 26, 2023 Thanks Craig, Will check them out. Quote Share this post Link to post Share on other sites
echorley 6 Posted February 1 Oooh, hello! I hope you don't mind me jumping on but I'm having the same issue with my MK3 Noob question here... how do I check to see if something is earthing both the gauges? Thank you Quote Share this post Link to post Share on other sites
norton 86 Posted February 2 as i understand it, the symptom of a faulty voltage regulator is for the fuel to show max and the temp zero. yours are both showing max? Quote Share this post Link to post Share on other sites
sheffieldcortinacentre 610 Posted February 3 They will both usually stay at the bottom. Quote Share this post Link to post Share on other sites
norton 86 Posted February 8 (edited) On 2/3/2024 at 8:44 PM, sheffieldcortinacentre said: They will both usually stay at the bottom. my source for my opinion is here from Ford Forums. "I’m detailing this post as I have just solved this issue and found there wasn’t much support out there. I did this on a 1982 mk5 cortina L 1.6 pinto but it should be similar on most mk5 cortinas. I had a temp gauge showing below 0 and a fuel gauge stuck at full and neither would move. If a dial is on full it means a shorted circuit and if it reads empty it’s an open circuit. " https://www.fordforums.com/threads/mk5-cortina-fuel-gauge-and-temp-gauge-not-working-fix.316334/ Edited February 8 by norton Quote Share this post Link to post Share on other sites
John Mack 286 Posted February 8 3 hours ago, norton said: my source for my opinion is here from Ford Forums. "I’m detailing this post as I have just solved this issue and found there wasn’t much support out there. I did this on a 1982 mk5 cortina L 1.6 pinto but it should be similar on most mk5 cortinas. I had a temp gauge showing below 0 and a fuel gauge stuck at full and neither would move. If a dial is on full it means a shorted circuit and if it reads empty it’s an open circuit. " https://www.fordforums.com/threads/mk5-cortina-fuel-gauge-and-temp-gauge-not-working-fix.316334/ I don't think you read that correctly ?..........That guy states the VR fixed the fuel gauge but NOT the temp gauge, to fix that he replaced the temp sender. Quote Share this post Link to post Share on other sites
norton 86 Posted February 10 (edited) Yes , I can see what you mean. Presumably both the VR and the temp sender were faulty, if it fixed his fuel gauge So a faulty VR would also show no reaction, makes more sense really. Fortunately I'm psat the head scratching period and the sender i have now in the tank works perfectly. I also rebuilt a spare one from the two scrap old ones I had whic works on the multimeter, so I'm good for a while I still have the two crap Motomobil new ones , which work but show the wrong reading by a country mile (ie permanently full....) The multimeter readings on these are way more what they should be. (ie 600 instead of 80) Motomobil wont take them back unless they are faulty, and I don't think it's worth the expense to prove the reading are wrong, which would involve an Engineer plus a german translation of documents and the European small claims Court fee. Edited February 10 by norton Quote Share this post Link to post Share on other sites