SteveHobart 57 Posted March 13, 2021 Hey all I am having some issues with my Alternator not charging the battery. For background, I have completely rewired the car as I have relocated the battery to the boot and installed a MS3X to run the new EFI CrossFlow engine I have built. At the moment I have the 12V input wire to the Alternator running off the Relay for the Thermo Fan (I have checked the input voltage and it’s 11.98V to the Alternator). The alternator output goes straight to the Positive Distribution Block under the bonnet via an (oversized and insulated) charge cable. On the output pin of the alternator I have the insulation disk under the (assuming) voltage regulator and then the output cable. Pics below. The only ‘modification’ to the alternator was I took the pulley off it as my youngest dropped it (for me) and I had to straighten up one of the fins. Help, I have no idea where to go with this next (except replace the Alternator). Cheers Steve Sent from my iPhone using Tapatalk Share this post Link to post Share on other sites
SPArKy_Dave 8,826 Posted March 16, 2021 Is the charge light connected? If the dash 'charge' warning light wiring isn't connected, the alternator field windings won't get excited, thus the alternator won't generate any voltage. Share this post Link to post Share on other sites
SteveHobart 57 Posted March 23, 2021 Hi Dave! Thanks for your input. Yes, the charge light is working correctly, on when in ‘Ignition On’ position and goes out when the car starts.Still no charge on the alternatorSent from my iPhone using Tapatalk Share this post Link to post Share on other sites
deankxf 20,231 Posted March 23, 2021 On 3/13/2021 at 4:15 PM, SteveHobart said: the only ‘modification’ to the alternator was I took the pulley off it as my youngest dropped it (for me) and I had to straighten up one of the fins. very possible something broke in it(due to being dropped). if you have a friendly auto electrician nearby you could drop it in to have looked at? Share this post Link to post Share on other sites
SteveHobart 57 Posted March 23, 2021 Hi Guys. Yup, alternator checked ok. Sent from my iPhone using Tapatalk 1 deankxf reacted to this Share this post Link to post Share on other sites
deankxf 20,231 Posted March 23, 2021 3 hours ago, SteveHobart said: Hi Guys. Yup, alternator checked ok. Sent from my iPhone using Tapatalk some alternators (i haven't looked into it at all) need a POSITIVE wire (ign on from somewhere) added to them to excite them.. @SPArKy_Dave may understand or you might be able to google it and see if that checks out. i've only ever used stock for stock or paid an auto elect to fix it Share this post Link to post Share on other sites
SteveHobart 57 Posted March 23, 2021 Yes, it need an exciter wire. It’s the spade terminal on the back of the alternator.On the XF it’s actually the ALT warning light on the dash providing the exciter charge.That’s all good on this set upSent from my iPhone using Tapatalk Share this post Link to post Share on other sites
SPArKy_Dave 8,826 Posted March 23, 2021 Stands to reason, it should work then? If the charge/alt light goes out, when the vehicle starts, then it should be generating a voltage. Have you earthed the engine block? (earth from bell housing to firewall, and from cyl head to battery) If the engine block isn't earthed relative to battery negative, the alternator obviously won't work. 1 deankxf reacted to this Share this post Link to post Share on other sites