We have a 2001 2500 that showed a "check gauges" light last night coming home (lights on, everything else off). The voltmeter was halfway between 0 and 14. I checked battery voltage when the truck was off and then battery voltage while running. 12.3 volts for both. Cleaned cables, charged overnight and it started right up and ran fine but same voltmeter reading on dash (but NO "check gauges light today). Drove to work, charged the battery to 13.3V, and on the way home it sometimes showed a little over 14 volts, and then went down to 7-8 volts. I noticed both nights on the highway an unfamiliar, low volume, random "click" seeming to be coming from under the gauges area of the dash. Random clicks then none, then more. All other gauges (including aftermarket fuel pressure, turbo vacuum, and pyrometer) were normal and the truck seems to run fine. I ordered an alternator, but am wondering now if it's something else. Does the alternator usually charge sometimes and then not, or is it either completely good or trashed? Any suggestions helpful. My wife and I are working 800 miles from home and need the daily transportation. I am NOT a mechanic!!

 

Chances are its your alternator. My 01 did the same thing, volt gauge would drop below 9v. Installed a new alternator at a Napa parking lot while on a hunting trip, and havnt had a problem since.. that was 4 years ago. Make sure the 'hot' wire on the alternator is clean and tight also...

 

You can get it tested...

Check wiring and grounds for clean connections and tight nuts.

 

It's like a curse or something! I read this post last night and sure 'nuff my frickin alternator starts doing the same thing today. And yes, my nights are waaaaaaaay tight! Alternator is OEM and still pumping out 13.8V to the batteries. I'll be keeping tabs on this one.

Cheers!

Mike

 

Might want to check the grid heater relays.

 

Update.
Time was of the essence, so I couldn't get the old alternator bench tested since I'm in a really rural area currently. A local mechanic ordered one and put it on and it must have been bad out of the box; fried the wiring of the alt. Ordered an identical replacement and put it on. It was charging fine on the first day. Now the same thing is happening with the new one. It shows about 8 volts at idle, but a little over 14 on the highway. In the early AM when I turn the lights on, they alternate between dim and normal. When I get on the highway the voltmeter again reads normal and I don't notice the lights dimming any more. Since it seems to charge fine on the highway, I'm going to try to drive it home (750 miles) this weekend where I know people who can run the codes, etc. Any ideas on what it is? ECM?

 

actually that's pretty normal. that's just your grid heater cycling. it will stop around 3-4 minutes after start up or until you reach a speed of 20 mph. years ago that threw me for a loop too, but the grid heaters use a lot of power.

 

Montemorris,
Like DUBC said, that it normal behaviour for our trucks. Check the post I have sent you a link to below.

https://www.dieseltruckresource.com/...t-t120532.html

It isn't a long post but it was one of the first things I read when I got my truck a few years back. Those grid heaters are like big toasters and they draw a lot of current when they are heating. I am not sure if you have daytime running lights on your truck but if you do, they are also on while you are heating your grids. On really cold start mornings I push the parking brake down 1 click while the grids are heating. That turns off the daytime running lights. As soon as truck is runing I release the parking brake.

 

Think this might just pull the juice down a bit?

 

Nice pic!

 

Agreed, nice picture. In case anyone ever wonders why you should NEVER use starting fluid / ether on our trucks, I think you now have your answer. Unlike glow plugs, those grid heaters are in the intake manifold not inside the cylinder / combustion chamber.

 

I going to order a grid heater relay (s?) for the stock 01. Suggestions on where to order for the best price? Can anyone direct me to instructions on how to install it (them?)?
Thanks.

 

Here is what you are looking for:

http://www.fostertruck.com/dodge-***...for-94-02.html

About the cheapest I have found them is Rock Auto, look for your year, under Electrical, switch and relay, then Intake heater relay.

http://www.rockauto.com/

Just a tick under 53 bucks at Rock.

 

Thank you Patdaly. Ordered.