SpitfireGeorge Posted August 18 Report Share Posted August 18 Hi Guys, Trying to get my Yazaki ammeter working. Connected one side of the gauge to the thick single brown wire connector on the control box terminal B and extended that wire to the other side of the gauge. Nothing showing on the gauge when I turn the engine over. I replaced the gauge when I tried to get it working before with another off Ebay. Can I test the gauge directly from the battery or will that burn it out. Am I using the correct terminal on the control box or should it be connected to another? Cheers, Brett Link to comment Share on other sites More sharing options...
johny Posted August 18 Report Share Posted August 18 Think Im right in saying the thick brown is to the main light switch so will only show current flowing when the lights are turned on.... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 18 Author Report Share Posted August 18 Looking at the wiring diagram there are 3 brown wires on terminal B. One goes to the starter solenoid, one to the ignition switch and one to the master light switch. Phsically on B the wires are split between two terminals, one wire on one terminal and 2 browns on the other. The wiring diagram just shows 3 wires on B so cannot tell which is which. Link to comment Share on other sites More sharing options...
johny Posted August 18 Report Share Posted August 18 As youve got it wired what happens to the ammeter when you turn on the lights? Link to comment Share on other sites More sharing options...
johny Posted August 18 Report Share Posted August 18 Im using this diagram and I suppose you really want the ammeter just in the wire connected to the starter solenoid so you can see whether battery is charging or discharging... 1 Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 18 Author Report Share Posted August 18 Nicer wiring diagram than mine. From that I need to use the double brown wire connection not the single. Will try that and report back. Thanks Johny Link to comment Share on other sites More sharing options...
johny Posted August 18 Report Share Posted August 18 looks like it but they need separating dont they? Otherwise it wont be easy to see whether the battery is supplying the running car (battery discharging) or the dynamo/regulator is working properly and doing it... Link to comment Share on other sites More sharing options...
johny Posted August 18 Report Share Posted August 18 (edited) oh and diagram is courtesy vitessesteve free to download workshop manual👍 Edited August 18 by johny Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 18 Author Report Share Posted August 18 You are right Johny the single brown wire is for the lights. Turned on my lights and the ammeter moved to discharge. Will use the other wires tomorrow and hopefully that will be it! Thanks again. Link to comment Share on other sites More sharing options...
johny Posted August 18 Report Share Posted August 18 Good and I reckon you do want to install the ammeter in just the wire to the battery because the although you have an ignition light this just shows the dynamo/regulator is working correctly NOT whether the battery is charging or discharging. Its quite possible to drive your car using just the battery to power its systems and as the ignition light isnt illuminated the first you know is when it conks out cos the batterys gone flat.... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 19 Author Report Share Posted August 19 Hi, Just tried connecting it to the other B terminal, 2 wires one to solenoid and one to ignition, but on turning the engine over no movement on the ammeter. Would it work if I connected it to the cable where it joins the solenoid? Cheers Brett Link to comment Share on other sites More sharing options...
johny Posted August 19 Report Share Posted August 19 well that way will only show a current flow when the dynamo is producing and supplying both battery and ignition switch. If engine not running the battery is just supplying directly to the ignition as the two wires are connected together. Im not sure what youre trying to acheive Brett... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 19 Author Report Share Posted August 19 Hi Johny, When my Spitfire was last run, early 1980s, the ammeter showed discharging when trying to start and then charging when it fired up. I am hoping to get the same again. On checking how to fit an ammeter on the internet it says use terminal B on the control box. I know the ammeter works from connecting it to the single brown wire on B and operating the lights. However connecting it to the other brown wires on B shows nothing on the ammeter when trying to start. Should it be connected to B or some other terminal on the control box to get it working correctly? Cheers Brett Link to comment Share on other sites More sharing options...
johny Posted August 19 Report Share Posted August 19 right well you cant use the ammeter to read the starter current as thats much too high but you can see the battery supplying the cars systems (discharging) and then once engine running the dynamo taking over (charging). As I said to do this you have to connect the ammeter just in the brown wire to the solenoid so first identify it out of the two small browns then work out how youre going to make the connections to both the regulator and ammeter. Remember when charging the ammeter could carry up to the full rating of the dynamo, aprox 22 amps, so the connections must be good and solid... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 19 Author Report Share Posted August 19 Hi Johny, I would have expected it to work using both the brown wires as they are connected together. The second of the 2 wires is connected to the ignition switch which would contribute to any discharge amps. If I need to just connect to the single brown wire going to the solenoid why wouldn't work if I put the ammeter between the other end of the brown wire and the starter solenoid? Cheers Brett Link to comment Share on other sites More sharing options...
johny Posted August 19 Report Share Posted August 19 yes but if you keep the wires connected the battery (engine off) will supply the car because both brown wires are connected together without going through the ammeter so it'll read nothing. Then once started the power to both the car and battery will go through the ammeter from terminal B with no way to disguish between the two! No problem at all connecting the ammeter at the solenoid, it'll work perfectly. Its which ever cable route is easiest.... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 19 Author Report Share Posted August 19 Thanks Johny I will try connecting it to the brown wire at the starter solenoid end. So new wire from solenoid to ammeter and original solenoid brown wire to other side of ammeter. I will see how that goes. Cheers Brett Link to comment Share on other sites More sharing options...
johny Posted August 19 Report Share Posted August 19 Should be a good'un although might have to swop the connections round at the ammeter to get charge/discharge in right directions. It wont read a lot before starting as the current draw is low but putting on indicators, windscreen wipers etc should be enough to test it👍 Link to comment Share on other sites More sharing options...
johny Posted August 19 Report Share Posted August 19 oh and make sure all cables and terminals are well protected from sharp edges etc as none of this is protected by fuses... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 20 Author Report Share Posted August 20 No that did not work either. A very small discharge was indicated when starting the car but when it fired up the reading went to zero. Think I will get the local garage to fix it when they do the pre-use safety check. Had enough of it to be honest. Thanks for your help Johny. Link to comment Share on other sites More sharing options...
johny Posted August 20 Report Share Posted August 20 Did you get the right brown wire at the solenoid as in the diagram looks as if theres two on the same terminal with the other supplying the horn? If you disconnect the correct wire nothing will work on the car except the horn... Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 20 Author Report Share Posted August 20 That's a point I will take another look. Cheers. Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 20 Author Report Share Posted August 20 Hi Johny, Had another look. Used the none-horn wire but same as before. Moved to small discharge when ignition switched on but centralised on starting engine. Tried other wire out of curiosity but nothing happened at all. Ah well never mind. Cheers Brett Link to comment Share on other sites More sharing options...
johny Posted August 20 Report Share Posted August 20 Only possibility I can see is that your battery is so good that it hardly needs any charging after a start so the meter being pretty crude doesnt register the current flow. Either that or your dynamo/regulator isnt working😲 Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted August 20 Author Report Share Posted August 20 Must admit I thought about the dynamo but I fitted new brushes when I installed the engine, also the ignition warning light goes out as I rev the engine. The battery is fully charged before I start the engine. Might need an auto electrician to sort this. Cheers Brett 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