One of my beloved del Sol VTECs (the '95) didn't start this morning. It has a fairly fresh (<1 year) battery but read 11V when checked before jumping. Started okay with my little micro jumper and got the following voltage readings while driving:
- Mostly ~13V
- Occasionally (at idle) ~12V

It started fine the next time but the voltage readings (and the fact that it was dead after only a couple of weeks of sitting) has me searching for a "semi-preventative" fix. The voltage readings seem low to me (by 1V) but I don't normally display / monitor that in this car. I'll see what my '97 shows but I expect it to be higher and you all to say it is low. Is it? When it is at 12V and I turn the fan to 2, it goes back up to 13V. All connections seem clean and tight. I did the grounds maybe a year ago or so.

I think it is the original alternator so it's definitely time for a replacement. Any recommendations for alternator replacements? I'm trying to keep this thing as stock / OEM parts as possible but all I see is a possible $400 unit on ebay.... I know that the autozone ones are like 50/50 and don't want to deal with that.

Thanks for the input!

 

You could look for new brushes and a regulator, rebuild your old one for a lot cheaper if you can get yours apart and if the bearings still seem good.

 

That may turn out to be the best option, thank you for bringing that up! It's definitely possible (if parts are available) because the '95 isn't my daily.

Any input on the 12V/13V being low or normal readings?

 

Denso remans are great. You can even find them on Amazon with Prime shipping.

Check and replace your main engine grounds with OEM (cheap and work great), first, and do a voltage drop test across your main alternator feed from the alt to the underhood fusebox, before you toss and alternator at it. 13V is iffy.

 

12/13V is way too low of a voltage reading with the engine on. Check the reading of the battery, with nothing on, keys not in ignition cylinder. The battery terminals should be around 12.3VDC and higher

Did you happen to check the alternator belt?

 

If the voltage goes up when you turn on the fan, that shows that the alternator is doing its job, Clean ALL the connections and grounds My 1995 civic lx has 420k miles on the alternator so either I have really good luck with alternators or these things just dont go bad for no reason.

 

+1 on rebuilding your alternator. I have the original 1993 Mitsubishi alternator with 200k+ miles on it, still in service on my Civic. I rebuilt it when I was doing a bunch of work on my car and I was able to just change the brushes and bearings in it, still has original regulator. Your regulator may be bad but you can find the oem Mitsubishi ones on ebay. If your alternator is Denso those are top notch too. If you need something quick then you could try a re-manufactured Autozone alternator, at least they have lifetime warranty

 

The grounds are OEM, what I meant when I said that I "did them" was that I cleaned / sanded the surfaces. All seem tight still. Voltage is same at battery as past the alternator.

Battery is all charged now and staying at around 12.8. Belt seems good and not slipping.

Can't it also mean that it is doing its job just not as good as it is supposed to? I'll look through the connections again.

I'll see if I can source the rebuild items.

Observed the voltage in my '97 and it was a very steady 14.2/14.3. Thank you all again for the input. I'll go through the ground connections again and take some more readings but am leaning towards trying to rebuild the one I have on there now.