I was on the freeway today, and my check gauge light came on, and my voltage gauge had spiked, maxing the gauge at the top end. It lasted for a few seconds, then the gauge would slowly drop back down to the normal position of about 14. It did this twice, the second time actually lasted longer. I didn't have any other abnormal readings on any of my gauges, and it didn't change how it was running. If it makes any difference, my smarty is currently unloaded, so I was on the stock computer settings. Any theories would be welcome, kinda freaked me out a little, since I was going 70mph, about an hour away from home!

 

Seems very odd, I would put a Multi Meter into the power outlet or cigarette lighter while driving and see what it says while driving. This will tell you what the actual battery voltage is.

 

No codes?

 

Voltage regulator

 

I guess I did have a code 1594, which is charging system voltage to high, but I already knew that! The regulater is what we were thinking, but honestly I haven't been back in the truck yet this week, so I haven't really looked at anything. Anyone know where the regulator is?

 

The voltage regulator is actually a voltage regulating circuit located within the Powertrain Control Module (PCM).If it is bad you have to replace the (PCM).

 

I believe there is a way to rewire it with an external regulator to avoid replacing the PCM. I'll see if I can find something for you.

 

Ok,

Try this on for size - courtesy of our friends at DTR:

http://www.dieseltruckresource.com/d...tage+regulator

more info here:

http://www.dieseltruckresource.com/d...tage+regulator

More:

http://www.dieseltruckresource.com/d...tage+regulator

One last bit - I know it says its for a first gen but it will work for a second gen:

http://www.dieseltruckresource.com/f...n&onlynewfaq=1