I noticed yesterday night that when the aux. cooling fan kicks on I was getting a very slight illumination of the "battery" light on the all-in-one combo. gauge. It would actually get a little brighter (not much) as RPM was increased. Obviously if I put more load on the system (lights, blower motor, rear defroster, etc) the light would get a little brighter. It still isn't what I'd consider "illuminated" and it stays completely off most of the time, but I read that this can either be an alternator starting to go or bad grounds. An alternator replacement is straightforward enough, but before I eat $300 for a replacement, I'd like to diagnose first.

What's the best way to check the grounds? Just clean them / sand the connections a bit or what?

 

you can clip one end of a meter on a clean bare metal spot on the frame and then check resistance to the ground in question.

 

My grounds were sort of messed up, I simply disconnectted most of them, cleaned and put them back on. My up 'til then mysterious overheating problem and bouncing temp needle disappeared! There are quite a few grounds, do a search under 'grounds' and you'll find some posts about where each ground point is. Please try that first before spending $300 and time. Good luck and post what the problem is and how you fixed it.

 

And before you spend $300, PM IceShark about the problem.

 

Talk to Iceshark. He will set you up with a nice ground kit. I just recieved mine yesterday. Very nicely made.

 

You can get just the ground kit for around 75.00

 

OK cool guys, thanks for the help. . . I'm suspecting it's the grounds (given that they're a known problem on these cars) and the P.O. neglected a LOT of maintenance (he had the car sitting on blocks for almost a year while redoing the clutch) during which time I doubt ANYTHING was done - plenty of time for grounds to oxidize, etc. I've had alternators fail on other cars before and they seem to fail more noticeably than the symptoms I have. I drove the car about 60 miles yesterday, not even a hint of the light starting to glow (then again, it was daylight), so to me I'm guessing (hoping) that it is the grounds juuuuuust starting to interfere with the proper flow of electrons. In any event, I'll let you all know.

 

Look at the wires. If the plastic is dry and brittle, and you have massive corrosion, replace the cables.

If it looks good, just clean them up.

You can also do a temp measure, and or see if grounds are your issue by running extra wires to the ground points (Using as heavy a gauge wire as you can find) if your grounds are bad this will cause a noticeable improvement.