Charging Light on S2 not lighting up.
Discussion
Hi Guys
Hoping someone may be able to advise, give me a pointer on what to do regarding my s2.
Just started the car to get out of the garage to prepare for the up coming summer and noticed the alternator charging light not coming on, always has done the usual before , stays on until 2k revs then goes out. Also noticed the volt meter is registering a low charge, even after blipping the revs over 2K.
Tried looking at the instrument bulb cluster, but have made this worse now, as the full headlight bulb indicator has now stopped working also!
Any ideas on what is causing this charging issue, as if a bulb in the cluster I cant see how you change that and not sure that would cause the volt meter to show low charging.
Any help would be greatly appreciated.
Thanks!!!
Ps
Any good tvr electircal mechanic recommendations in Suffolk?
Hoping someone may be able to advise, give me a pointer on what to do regarding my s2.
Just started the car to get out of the garage to prepare for the up coming summer and noticed the alternator charging light not coming on, always has done the usual before , stays on until 2k revs then goes out. Also noticed the volt meter is registering a low charge, even after blipping the revs over 2K.
Tried looking at the instrument bulb cluster, but have made this worse now, as the full headlight bulb indicator has now stopped working also!
Any ideas on what is causing this charging issue, as if a bulb in the cluster I cant see how you change that and not sure that would cause the volt meter to show low charging.
Any help would be greatly appreciated.
Thanks!!!
Ps
Any good tvr electircal mechanic recommendations in Suffolk?
Do you have a volt meter? Less than £10 at Screwfix
You can check the alternator is working by measuring the battery voltage when running/not running and also the alternator output. It’ll be higher when charging as you would expect.
Check all your battery and alternator connections.
If all good you’ll need to trace the wiring back to the dash testing with a volt meter as you go.
It could just be the charge light bulb but start with the easy to get to stuff first
N
You can check the alternator is working by measuring the battery voltage when running/not running and also the alternator output. It’ll be higher when charging as you would expect.
Check all your battery and alternator connections.
If all good you’ll need to trace the wiring back to the dash testing with a volt meter as you go.
It could just be the charge light bulb but start with the easy to get to stuff first
N
Generally the alternator will be energised via the ignition light. Sounds like there is no connection to the alternator via the light or the alternator has failed. You need to check the bulb. If it looks to be okay check there is 12V to the bulb and then check all the wiring to the alternator. If there is 12V to the alternator on the fine wire (not the main power wire) it will be the alternator. I have come across a similar problem a couple of times (not on TVRs) and both times it was actually the alternator itself.
Cheers
Dave
Cheers
Dave
A traditional alternator has one small wire. (& one or two thick wires).
You turn the ignition on - 12 volts (battery voltage) from position 2 on the back of the ignition barrel travels through the warning lamp (note, through the bulb filament, not to one side of the bulb holder) - if the bulb filament is blown the 12 volts stop here & doesn't go to the alternator and the alternator is not energised - assuming the bulb is OK the 12 volts travel to the small terminal on the alternator then through the diode pack to earth (alternator body usually gets it's earth by being bolted to the engine block - two things happen, the alternator is now energised and by going to earth through the diode pack the bulb on dashboard now has an earth on one side & still has 12 volts positive on the key side, so it illuminates - when the engine is started & charging begins (sometimes a brief blip of the throttle is needed) the diode pack switches the small terminal to 12 volts positive, so now the warning lamp has 12 volts positive on both sides of the bulb holder & goes out.
The thick charging wire(s) on the alternator, which at rest engine off would have been at 12 volts battery voltage, will now be charging at something like 13.8 to 14.2 volts. ( Newer cars with stop-start and newer battery types will charge even higher. )
Getting back to the car - turn the ignition on, if the warning lamp doesn't illuminate put the small wire on the alternator to earth (alternator body) - if the warning lamp now illuminates, it suggests that every thing back to the key is ok and no dashboard stripping is required. This situation suggests that the diode pack (usually inside the alternator) is faulty. (Assuming that the alternator is earthed & the thick charging cable(s) are ok, showing battery voltage.
You turn the ignition on - 12 volts (battery voltage) from position 2 on the back of the ignition barrel travels through the warning lamp (note, through the bulb filament, not to one side of the bulb holder) - if the bulb filament is blown the 12 volts stop here & doesn't go to the alternator and the alternator is not energised - assuming the bulb is OK the 12 volts travel to the small terminal on the alternator then through the diode pack to earth (alternator body usually gets it's earth by being bolted to the engine block - two things happen, the alternator is now energised and by going to earth through the diode pack the bulb on dashboard now has an earth on one side & still has 12 volts positive on the key side, so it illuminates - when the engine is started & charging begins (sometimes a brief blip of the throttle is needed) the diode pack switches the small terminal to 12 volts positive, so now the warning lamp has 12 volts positive on both sides of the bulb holder & goes out.
The thick charging wire(s) on the alternator, which at rest engine off would have been at 12 volts battery voltage, will now be charging at something like 13.8 to 14.2 volts. ( Newer cars with stop-start and newer battery types will charge even higher. )
Getting back to the car - turn the ignition on, if the warning lamp doesn't illuminate put the small wire on the alternator to earth (alternator body) - if the warning lamp now illuminates, it suggests that every thing back to the key is ok and no dashboard stripping is required. This situation suggests that the diode pack (usually inside the alternator) is faulty. (Assuming that the alternator is earthed & the thick charging cable(s) are ok, showing battery voltage.
Guys
Thanks for all your advice. Looks like I have resolved it. After testing all wiring, all checked out ok, I purchased what I thought was a suitable replacement red bulb unit from TVR Racetech, and once fitted the light came on.. BUT did not cut out or start charging when rev'd, no matter how hard.
Spoke to several people and was told the replacement bulb was probably for the TVR Griff and would be a LED, hence not providing the correct power needed to the alternator, as TVR did a worked around from the original S problem on the Griff by using ceramic resisters to create the correct power.
I really struggled to find the correct ceramic resister, so ended up going to a web site called Car Builder Solutions and found a red bulb holder, where the bulb could be replaced (unlike the TVR one) and worked perfectly, goes off and starts charging without having to rev up to 2k like previously.
Part number WL5 BCR
I hope this helps if anyone is having the same problem.
Thanks for all your advice. Looks like I have resolved it. After testing all wiring, all checked out ok, I purchased what I thought was a suitable replacement red bulb unit from TVR Racetech, and once fitted the light came on.. BUT did not cut out or start charging when rev'd, no matter how hard.
Spoke to several people and was told the replacement bulb was probably for the TVR Griff and would be a LED, hence not providing the correct power needed to the alternator, as TVR did a worked around from the original S problem on the Griff by using ceramic resisters to create the correct power.
I really struggled to find the correct ceramic resister, so ended up going to a web site called Car Builder Solutions and found a red bulb holder, where the bulb could be replaced (unlike the TVR one) and worked perfectly, goes off and starts charging without having to rev up to 2k like previously.
Part number WL5 BCR
I hope this helps if anyone is having the same problem.
Gassing Station | S Series | Top of Page | What's New | My Stuff