Charging Light - Question

Paylrider · Post by **Paylrider** » July 29th, 2005, 8:09 pm

Well when it rains it pours, got my temperature guage working, it is the single lead sensor that runs the temp guage on a K-8 engine, now the alternator light is on. The connections are all good and when the positive on the battery is removed it dies, belt is tight and alternator spinning. Is there anythig other than a bad alternator that could cause this? Voltage regulator perhaps, and how can you tell the difference which one is bad.

papa roached · Post by **papa roached** » July 29th, 2005, 8:21 pm

the regulator is build into the alt so either way the alt is bad

jschrauwen · Post by **jschrauwen** » July 30th, 2005, 1:27 pm

Paylrider, It may prove beneficial to give a little history when posing questions. Including specifics in your signature block (via a profile input) will make the reponses more precise and less generic. WRT your charge light there's going to be a lot that may just see the title of your query and give a generic answer to your question - they're not going to be fully aware of the history preceding your difficulties unless they made it a point to go through your specific previous posts - which really won't happen. So basically 2 options - a long drawn out precis before posing your problem or an indepth desription of your MX in your signature block that would include updates, mods, changes etc. WRT to your charging light, it may prove advantageous to inform the BB that you've just completed a engine change using a 95 engine into a 92 MX. That makes a difference in various ways as you've already experienced with your thermosensors/temp guage problems. I believe there were subtle wiring changes after 94 which would require slight modification to ceratain items if being swapped over from either side of the the '94 year....I believe. This may be the case with your Alt. You haven't mentioned that you are using the 92 or a 95 alt. This may make a difference in your particular case. Post those particulars as far as which alt and there may be a better response. I'm not one for giving intuitive advice in that area and I'm not sure if the on-line manual will shed any more light. I would however recommen that you have a look at "Grants" site. He has quite a bit of exprience in this particular area and may have a simple solution than thinking of purchasing a new alt. You may only need a simple wire re-configuration to make the alt work....it's worth a try.
Compare the '95 wiring diagram as it pertains to the alt to the '92 wiring diagram.
http://www.mx3er.com/Info/1992%20Wiring%20Diagrams.pdf
http://www.mx3er.com/Info/1995%20Wiring%20Diagrams.pdf
Thes are from Grants site http://www.mx3er.com
Hope this helps;
john

I tried you ph# this morning.......no joy.

PATDIESEL · Post by **PATDIESEL** » July 31st, 2005, 2:26 am

From what I know, which means that I am not 100% sure, the wiring for any year KL will be the same as any MX-3 GS (any year) for the Alt. So that your problem is the Alt. Also that is the correct way to test for a bad Alt. (to take the battery cable off and see if it dies) A faster way to just check the Alt instead of going through wiring diagrams is to take it off and bring it to Auto Zone. They will test it for free.

Paylrider · Post by **Paylrider** » July 31st, 2005, 10:03 am

Well after carefuinspection I determined that the alternator was bad, no juice to the battery at idle, a new alternator was purchased and installed and the light is now out.