So the temp outside is -30 so I figured I would try and figure out what's wrong with my dads 2000. What's happening is his grid heater realys are only getting 8v from the ECM. I had already changed out the grid heater relays one was slightly melted. I put a jumper strait from the battery and everything works great. My next thought was to have the ECM reflashed but I figured before I send him to the dealer I would see if anybody has had this problem before. Thanks in advance Abraham

 

8v sounds about right, as the ecm should be using 9v (i could be mistaken) ecm will only trigger grids under certain conditions, you can also wire them up to be triggered manually. when you turn the key to on the grid light will come on as per normal, just hold the switch when the light goes off let go of the switch, I'm not a fan of the ecm controlled grids as usually they stick on (as yours did as indicated by the melted relay) or cycle on/off when its not required. when they do stick on they either take out the alternator or kill the batterys.

do you know how the grids are susposed to cycle?

 

Thanks for the quick reply I thought the grid heater timing was based on inputs from the intake air temp sensor and one it hits 60f it stops cycling. I had talked to my dad about putting in a pushbutton switch, but since pushing a button is so hard he wasent to thrilled with the idea. Thanks Abraham

 

its based off of IAT, veh speed, outside temps etc, the ecm alternates each grid for up to two mins after start up.

here is a link to getting you started(for more use my sig nickg and ford starter relays in a google search)

http://www.cumminsforum.com/forum/98...r-relay-2.html