Electrical Issues

I was hoping for some advice on the steps I should take to troubleshoot some electrical issues I've been having lately. The symptoms are minor but they are bothering me. And, I don't have any experience using the new multimeter I bought so I would appreciate some elementary guidance.

1997 Ski Nautique, 5.8 carbed.
New:
Mallory Electronic Distributor and Coil (Discount Inboard Marine)
Marine Alternator
rebuilt starter
Marine Starter relay
Ignition switch

Symptoms:
Low voltage at the dash volt meter (never over 10V)
Hot to the touch Alternator (but no burning electrical smell)
95% of the time the boat fires and starts with barely a click of the key. When it doesn't I turn the key all the way right and it cranks without firing like it's not getting any spark.
The tach recently started getting jumpy and at idle and, when I know it's closer to 800, it reads 1000 rpm.

I'm not sure if these are related or being affected by separate issues but the motor runs flawlessly otherwise. After running the boat for a few hours, I tested the battery voltage with the engine off and it read 13.17V

Where should I start? Thanks in advance.

Thanks Brian.

So, was it pretty much all related to the alternator?

it doesn't sound like an alternator problem with > 14 volts while running. consider other options first.

BuffaloBFN wrote: Jones wrote: Low voltage at the dash volt meter (never over 10V) You're chasing a bad ground. Sounds like the alternator is fine.

Don't rule out the hot feed to the dash ether! Both could be bad.

could try a new harness too!

http://www.skidim.com/products.asp?dept=1155

I doubted the bad alternator so I had it tested and it was fine. After some research I discovered the PO never had the sense terminal wired. Ive never had an alternator with an onboard VR so I didn't know what to look for. Every things fine now with 14.24v while running and it's no longer running hot but my dash volt meter is still only showing 10v. I'll double check ground and + but it might be a bad gauge. The tack is no longer jumping. I wonder if the over voltage could have had an effect on this.

Thanks, Pete. I'll start going through. I assume if I get less than 12v with the key on/engine off on any gauge, I've got a problem? I'd appreciate letting me know what to look for on the volt meter

Start checking for bad ground, bad connections an bad power.   
I went though the entire harness on my 90 sport.
Check your voltage from the battery through each connection to see where the voltage drop is. disconnect wires past where you are checking so you see voltage from the battery to that point.

Check all terminal connectors, repair or replace any that need it.
Put dialectric compound on every connection to prevent corrosion.

I had a bad ground connector in the wiring harness block, had to cut it out rewire it, soldered it, and molded it back in.

I wired a new +12 wire to the ignition terminal at the dash
cleaned up all the connectors
Ran a new ground wire from the engine block to a bus bar under the dash. and then had 6 different grounds from different areas wired to the bus bar.
With all this my running voltage came up from about 10.5 to 13 volts.
My gauges now read correctly.