The battery light came on yesterday and that tells me my alternator is failing or I have dirty electricals at the back of it. Failing is more my guess; it was intermittent but now constant. Tacho fails in sync with battery light. Obviously works of electrics somehow? Can someone help.

I’ve ordered a new alternator and will replacing it simply fix this issue.

Thoughts appreciated

 

yes...sounds like the alt is giving up, the tach signal comes from the alternator. While you're at it.....clean up the ground cables

 

Sounds like a RRC/D1/D90. If it's a GEMS based 96-99 D1 grab yourself a 95-98 P38 GEMS alternator. It's got more amps for the same price. When I had my D1 I did that when the reman the previous owner put in died. I grabbed a "Parts Player" unit off of Ebay and it was very high quality and worked great.