95 12valve, 5 spd, intake, exhaust, fuel plate...just a driver w/250,000 mi.

Just bought it about a week ago so don't know what's parts have recently been changed.

Issue: At start up the voltage will fluctuate from lets say 15 to 13 volts about every 6 seconds (very patterned and time doesn't fluctuate at all). Enough for the lights to dim and what not. This happens for a short time than goes away and stays @ 14/15 volts like normal.

Don't know if this is related or not but every once and awhile when I go to turn it over it just clicks like a loose wire. I haven't peeked around yet to try and find if it's just a wire or if there could be alternate problems associated.

Also, the truck runs cold. What's normal operating temps. Down the highway it'll only maybe get to 150?

Any info appreciated, thanks!

 

if your voltage fluctuation during startup is most likley caused by the heater grid cycling on and off during cold starts, it's common on all these trucks, not shure where I may have heard this from, but I do believe the intake pre heater draws about 200 amps, thats more than enought to dim the lights, etc... as for your intermittent starter issues, that could be a loose battery cable, dirty ground or dirty connection by the starter, have a look to see if there all tight, and while your there, give em' a good cleaning.

 

Put your location in you signature , it can help with finding members in your area , they may chime , when they see it .
What's the temp where your at , that would confirm the heater grid , it sound like that is what is happening , I start plugging my truck is as soon as it start getting cold enough to turn on the grid heater , makes for a lot of issue's , starter last longer , better millage , batteries last longer ++ .
For the temp that does sound low , get a thermostat from one of the equipment / farm dealers , make sure to ask for a 180*F , I went to Cummins , they gave me one that made the engine run a little cooler , maybe 165*F .

 

Michigan, so yeah, definately getting cold around these parts!!

 

Voltage is totally normal, as suspected, it is the grid heaters. It should not happen once the truck is above 20 MPH.

Change the thermostat, don't get a typical Autozone cheapie, I would get a genuine Cummins if at all possible, I have a Cummins in Brownie and a Napa premium in Greenie ( was all I could get in a pinch ) and Brownie runs right at 190, Greenie struggles to get to 180

Get ready for starter contacts as well, look at Foster truck for oversize contacts.