Posted October 13, 200519 yr Finally got round to converting kph to mph using the resistor way. Took out the r10 and replaced with 20k resistor. am not the best solderer going but it seemed ok. put it all back together and went for a test. as soon as i moved off the speedo needle started shooting up quicker than the rev counter!!!! Read 120 mph at approx 25mph true (from gps). then after that went back to zero and refused to move. tried to reposition needle but was still exactly the same. dont know wot went wrong. checked board again, all seems ok......... any ideas??? could i have damaged pcb. (as previously mentioned not the best with soldering). :headvswal :headvswal cheers nick anyone got a speedo for sale :( :(
October 13, 200519 yr once you stopped, does it work again ? if so, mine does the same i'm told its the speed sensor on the box
October 13, 200519 yr Author once you stopped, does it work again ? if so, mine does the same i'm told its the speed sensor on the box no, just the same as before. def something i've done cos it worked ok (in kph) b4. :confused:
October 14, 200519 yr Does it not move at all now, or does it still shoot up to 125 and then return to zero? Did you remove the speedo needle? Do you have a multimeter that you can use to make some resistance meaurements with?
October 14, 200519 yr Author Does it not move at all now, or does it still shoot up to 125 and then return to zero? Did you remove the speedo needle? Do you have a multimeter that you can use to make some resistance meaurements with? yep it still moves right up the scale at slow speeds, then goes back to zero above about 30mph(true). does the same each time i stop and move away again. did remove needle, but seemed to come off ok (without spindle). had no probs with needle when changing dials last year. yep got a multimeter. also cruise control not working nick
October 14, 200519 yr O.K. From the attached picture, 1.Test for resistance between red and green points (either end of the resistor) should read 20K. 2.Test for resistance between red and blue points (end of resistor to potentiometer in connection) should read 20K. 3. Test for resistance between red and yellow points (end of resistor to potentiometer out connection) should read approx 25k. Let me know the results.
October 14, 200519 yr Author O.K. From the attached picture, 1.Test for resistance between red and green points (either end of the resistor) should read 20K. 2.Test for resistance between red and blue points (end of resistor to potentiometer in connection) should read 20K. 3. Test for resistance between red and yellow points (end of resistor to potentiometer out connection) should read approx 25k. Let me know the results. thank's mate will try that later, am at work at mo (on pda) got a feeling i may have messed up the soldering, did it from back of pcb. :-(
October 14, 200519 yr Author O.K. From the attached picture, 1.Test for resistance between red and green points (either end of the resistor) should read 20K. 2.Test for resistance between red and blue points (end of resistor to potentiometer in connection) should read 20K. 3. Test for resistance between red and yellow points (end of resistor to potentiometer out connection) should read approx 25k. Let me know the results. ok done tests with following results with multimeter set to 20k ohms 1. 17.18 2. 17.18 3. 8.36 weird i thought so tested again. 1. 16.77 2. 16.77 3. 7.37 hmmmm. wot do u think ( apart from plonker!) cheers nick
October 15, 200519 yr At least it explains why it's not working! Please test between blue and yellow and let me know the result. Looking at your previous results it's not very clear whats wrong. Are you sure the results for tests 1 and 2 are 16.77K and not 1.677K, that would explain a few things. Can you read the colour code on the resistor? Did you buy the resistor in a sealed pack with the value on the pack?, do you have another resistor that you checkthe resistance of.
October 15, 200519 yr Author 4. blue yellow = 7.03 def got the point in right place with meter set to 20k. got them from maplins, loose. got several. very hard to read colour code clearly. 1st looks orange (but could be red, 20 or 30k :confused: ) 2nd and 3rd black 4th Orange or red ? 5th brown. starting to wonder if my meters playing up. tested spare resistor. meter on 20k gave reading of 1 . on 200k briefly flashed a figure b4 giving a reading of 1 . 0n 20m gave a reading of 0.30. think i'm losing the plot. have done the original tests with meter set to 200k with following results. 1. 44.7 2. 44.7 3. 37.0 4. 07.1 Have managed to get spare speedo (thanks topless) still in kph but at least i'm legal again, so i dont mind experimenting with this one now. still well confused though(not hard for me :headvswal ) cheers nick
October 15, 200519 yr From the colour code you have described it looks like you've got a 20 ohm resistor instead of a 20k ohm(20 000 ohm resistor). The colour code for a 20K resistor is red,black, orange. You appear to have red,black,black which is 20 ohms. To check set your meter to a 0-200 ohm scale(or therabouts)and test the resistor, think you'll find it reads 20 ohms.
October 15, 200519 yr Author From the colour code you have described it looks like you've got a 20 ohm resistor instead of a 20k ohm(20 000 ohm resistor). The colour code for a 20K resistor is red,black, orange. You appear to have red,black,black which is 20 ohms. To check set your meter to a 0-200 ohm scale(or therabouts)and test the resistor, think you'll find it reads 20 ohms. That might explain things. :o mind you just tested as you said and the only scale i could get a reading other than 1 from was the 20m ohms (got 0.30) ?????
October 15, 200519 yr Not sure why you're getting some odd sounding meter readings but I think you need to get a confirmed 20K resistor and try again. The readings you should get are 1. 20K 2. 20k 3. 27K(20k + 7K) 4. 7k Note the 7K reading is the potentiometer resistance and is variable between 0-10k it's this that you adjust to get the calibration right. (mine is at 5k but it'll vary depending on individual speedo). Let me know how you get on!
October 15, 200519 yr Author Not sure why you're getting some odd sounding meter readings but I think you need to get a confirmed 20K resistor and try again. The readings you should get are 1. 20K 2. 20k 3. 27K(20k + 7K) 4. 7k Note the 7K reading is the potentiometer resistance and is variable between 0-10k it's this that you adjust to get the calibration right. (mine is at 5k but it'll vary depending on individual speedo). Let me know how you get on! will do, job for tomorrow i think. thanks for all the help. will let you know what happens cheers nick
October 22, 200519 yr Author Update !!! All sorted now. Turned out i was given a 20 ohm resistor not a 20k ohm, bloody Maplins :rant: managed to get 22k one from mate and adjust it down with potentiometer (just). Todays moral is ... Dont buy from maplins unless you know what you're doing pay your £20 subscripton for great advice. :bow: :bow: thanks for all the help nick
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.