Brebs Posted April 15, 2012 Share Posted April 15, 2012 Can anyone please give me an idea where to start with this problem please. Indicators and brake are affecting the speedo. It doesn't happen all the time but basically if I put either indicator on the speedo needle waggles down about 20 mph each time the indicator flashes and when I press the brake the speedo needle drops to zero and returns to correct speed when I take foot off brake. Any ideas please. Thanks Brebs Edited by - brebs on 15 Apr 2012 19:20:54 Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted April 15, 2012 Share Posted April 15, 2012 Sounds like an earth connection - in a rear light cluster or under the dash by the wiper motor ? Damp IOW air ? 😬 Link to comment Share on other sites More sharing options...
charlie_pank Posted April 16, 2012 Share Posted April 16, 2012 Definitely an earth problem. Link to comment Share on other sites More sharing options...
Brebs Posted April 16, 2012 Author Share Posted April 16, 2012 Thanks chaps will whip the rear light clusters off and check the earths etc. Link to comment Share on other sites More sharing options...
Brebs Posted September 16, 2012 Author Share Posted September 16, 2012 Ok I know it's been a while since I started this thread but haven't got out much in the car this year. the problem still exists and now I think think it is getting worse. The oil pressure sensor has now become possessed and wiggles about erratically and sometimes just goes straight over to the far right and stays there. I have removed all rear light clusters and cleaned and checked all earth connections. What can I check for next??? Link to comment Share on other sites More sharing options...
Brebs Posted September 16, 2012 Author Share Posted September 16, 2012 Also still got the problem with the speedo Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted September 16, 2012 Member Share Posted September 16, 2012 Do the flashers and brake lights work correctly when this occurs? What type of speedometer? Which way do oil pressure sensors work? (Variable resistance to earth?) Have you disconnected, cleaned and reconnected the earth to the speedometer? (See SM25Ts suggestion.) Jonathan Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted September 16, 2012 Share Posted September 16, 2012 Also - time to go mechanical oil pressure gauge ! Wonder - disconnect cable from OPG sender. Do other problems go away ? You need to check all earth points and make sure contacts are clean, not corroded. The big ones from battery to engine and engine to chassis should also be checked and cleaned. Sure though it will be a 'small' earth under the dash. Link to comment Share on other sites More sharing options...
Brebs Posted September 16, 2012 Author Share Posted September 16, 2012 Thanks for the fast responses, determined to get to the bottom of it this time. Flashers and brake lights work fine as do the hazards. The speedo is an electronic one with the sensor on the rear right axle. Don't know about the way the oil pressure sensor works, sorry. I will try disconnecting the OPG sender today and see what that does. I have checked cleaned and double checked all earths in engine loom and main earth from battery and earth from engine to chassis. How many earths are there to check under the dash and where should they be earthed to? Thanks for the help. Link to comment Share on other sites More sharing options...
Brebs Posted September 16, 2012 Author Share Posted September 16, 2012 Where is the earth to the speedo ? Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted September 16, 2012 Share Posted September 16, 2012 Aha - right rear wheel speedo sensor !! We had a car on the IOM trip that died completely. Turned out to be the speedo sensor cable cable tied ti rear chassis - cable ties chafed through looped (over-long) cable. Shorting between various cores. Relatively easy fix. Understand it is not an uncommon problem with this cable ! Link to comment Share on other sites More sharing options...
The Pikey Posted September 16, 2012 Share Posted September 16, 2012 The indicators and brake lights get their earth from under the nose cone and not the wiper mount so I'd give that a go. Edited by - Jason Fletcher on 16 Sep 2012 18:09:34 Link to comment Share on other sites More sharing options...
anthonym Posted September 16, 2012 Share Posted September 16, 2012 is the feed for the wobbly guages all from the same wire to the fuse box? If you have a fuse box key there may be a clue there if it says simply "instruments"; in which case wiggle the fuse to polish the connects.. and so on. otherwise I agree with the earth thinking - multiple issues usually means an earth problem. Anthony Link to comment Share on other sites More sharing options...
john milner Posted September 17, 2012 Share Posted September 17, 2012 Twice in the last couple of months my speedo packed up for ten minutes and came back to life. The last time it went I had just turned the heater fan on. I had thought it was coincidence but after reading this I'm not so sure. Link to comment Share on other sites More sharing options...
Smiffy69 Posted September 17, 2012 Share Posted September 17, 2012 When I built mine I had an issue with my cycle wing indicators not working. They somehow were elctrically isolated from ground? I Solved this by running a separate earth from the engine mounts back to the wing stay indicators. I'm not saying this is the cause but until I fixed this I had all sorts of issues with incorrect tacho and speedo readings. Once earthed it all seemed to settle down. Might be worth checking earth continuity to these? Just a thought Link to comment Share on other sites More sharing options...
The Pikey Posted September 17, 2012 Share Posted September 17, 2012 Quoting Smiffy69: When I built mine I had an issue with my cycle wing indicators not working. They somehow were elctrically isolated from ground? I Solved this by running a separate earth from the engine mounts back to the wing stay indicators. They earth through the flexible brake hoses normally Jason Link to comment Share on other sites More sharing options...
Smiffy69 Posted September 17, 2012 Share Posted September 17, 2012 Thats what I thought but I have a R300 which seems to have some sort of composite caliper (possibly - happy to be corrected) ...and therefore it insulated everything - I did check the earthing of the brake hoses but all continuity stopped at the caliper ?! Running a separate earth solved it Link to comment Share on other sites More sharing options...
john milner Posted September 17, 2012 Share Posted September 17, 2012 I also had a dodgy earth to the indicators. The terminal appeared to be glued to the end of the wing stay and had come off. I ran separate wires back to the chassis. Link to comment Share on other sites More sharing options...
Brebs Posted September 18, 2012 Author Share Posted September 18, 2012 List of what I have done. Checked and cleaned all connections in following. Rear light clusters Number plate light Fog light Reverse light Checked and cleaned all multipoint connectors in the wiring loom going to rear lights. Checked gap on speedo sensor, cleaned it and the toothed wheel on axle. Also checked and re-routed the wiring for same (No chaffing or signs of wear) Checked and cleaned connectors to reversing light switch (Found one of these connections to be loose) The earths under the dash seem fine and are attached securely to the wiper mount however just to make sure I have ran a wire from this earthing point direct to the battery negative. I have checked cleaned and re-connecten the main earth leed from battery neg to the bell housing bolt. Also done same to the main earth cable from the left hand engine mount to the chassis. Ive moved the main earth under the nose cone from the left hand brake union and bolted it direct to the chassis just in front of the left hand nose cone securing bracket. I think the problem with the oil pressure guage is a faulty sensor so I have ordered a new one which should turn up today. The only thing that i have not done is to re-route or change the location of the earths on the front wing stays for the indicator repeaters they are currently connected to the end of the stays with a pop rivet. Probably going to do this in next couple of days. I don't have an opportunity to test drive it until Wednesday evening so I will update then. Thanks for everyones help. Link to comment Share on other sites More sharing options...
John Vine Posted September 18, 2012 Share Posted September 18, 2012 Hi Brebs, I suffered very similar speedo symptoms on my 2008 R400D (see here). I was tearing my hair out (what's left of it) in sheer frustration. I suspected electrical gremlins in the loom, earthing problems, and so on. I discussed it all at length with James Gibson at CC, and was even considering a complete rewire. He suggested that, before I took any drastic and expensive action, I simply try replacing the speedo. He kindly supplied one, and I installed it, not really thinking that it would help at all (especially as the original had already been replaced under warranty). But it solved the problem completely. So, can I suggest that you ask CC to lend you a speedo and see what happens? JV Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted September 18, 2012 Member Share Posted September 18, 2012 (Don't know anything about electronic speedometers.) Sounds as if you've done a lot of cleaning up. Hope it works. It would be interesting to swop the old OP sensor back in after the problem has gone away to see if that was the cause. Jonathan Link to comment Share on other sites More sharing options...
FoT Posted September 24, 2012 Share Posted September 24, 2012 For what it is worth, I had a similar problem recently with a Fiesta based kit car.... With the Engine Running, if I Pressed the Brake Pedal the Rev Counter dropped to zero and the the battery warning light (and others) came on.... Traced the problem to a faulty fuse connection Link to comment Share on other sites More sharing options...
John Vine Posted September 26, 2012 Share Posted September 26, 2012 Hi Brebs, how's the speedo? JV Link to comment Share on other sites More sharing options...
Brebs Posted September 27, 2012 Author Share Posted September 27, 2012 Have now also fitted the new oil pressure sensor and the guage for the oil pressure now working fine. When removing the old sensor I found the the black wire going into the connector was broken, the wires on the sensor are very thin! so if you find your OP guage going erratic and then just staying over to the far right thats probably what it is. The new sensor has much thicker wiring so I guess that this has been a problem in the past. The other thing I did was to put a second earth cable from the right hand engine mount to the chassis, can't have enough earths in my opinion. I have driven the car 50 or so miles since doing all this and fingers crossed the speedo has stayed steady as a rock. In the past if I wasn't getting the obvious speedo problem when indicating or braking I can always remember the speedo needle would move about 1mm to the left when first pressing the brake but that doesn't happen now it stays completely steady. The car seems to be driving better as well, just smoother and more evenly! So there you have it I think the problem is solved although I don't know what I did to solve it, i've listed everything so it was one or a combination of them. Thanks to everyone for your ideas and help. Now can anyone help with the speeding ticket that came through the door yesterday from my holiday in France! 118km in a 110km limit! on a road they charged me to drive on! In a French hire car! 68 Euro's ☹️ Brebs Link to comment Share on other sites More sharing options...
Eugene Posted September 27, 2012 Share Posted September 27, 2012 Quoting Brebs: Now can anyone help with the speeding ticket that came through the door yesterday from my holiday in France! 118km in a 110km limit! on a road they charged me to drive on! In a French hire car! 68 Euro's ☹️ I think you will find that's from the hire company - the French BiB can't chase you back to the UK. They can fine you on the spot only... It it were me, I'd ignore it, unless you intend to use the hire company again... 😬 Link to comment Share on other sites More sharing options...
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