The Diesel Stop banner

That time of year, Block Heater trouble.

3K views 17 replies 5 participants last post by  buckhunter1 
#1 ·
Hi Everyone,
I have a 2003 ford f 250 6.0 diesel super duty, I am from the east as far east as you can go, AC NJ any way, it has been in the 20`s already here, I want to plug in the heater and seen that the end of tne cord was burnt kind of bad, dose anyone know if that means the whole block heater is bad or can it just be the cord, I asked that cause I put a new plug on the end and still did not heat up, could it be the other end of the wire or do you think the whole thing is bad, I ask cause it is a big cost change, cord, $ 18.50 cord and heater $156.00 S/S don`t give me much to play with, Thanks for your time one and all, Thank You.
 
#2 ·
Very seldom does the actual heater goes bad. 99% of the time it is just the cord.

You can do a ohms test to check the heater. It should be around 15 ohms.

On the plug being burnt, that usually happens when there is a loose connection

Sent from my SM-J737V using Tapatalk
 
#3 ·
And when this happened to me, I received excellent advice here to look into the Marinco Mod...which has been improved upon by the NOCO Mod (the NOCO has a better rubber compound and remains snug in colder temps).
 
#4 ·
Hi Everyone,
I have a 2003 ford f 250 6.0 diesel super duty, I am from the east as far east as you can go, AC NJ any way, it has been in the 20`s already here, I want to plug in the heater and seen that the end of tne cord was burnt kind of bad, dose anyone know if that means the whole block heater is bad or can it just be the cord, I asked that cause I put a new plug on the end and still did not heat up,

Its very common for the cord end dangling loose to get corroded. That in turn creates a high resistance connection when you plug it in which makes the connection heat up. If the connection gets hot enough it will cook the plug and some of the close by cord.


Now you say you have replaced the plug end but still have no heater. Did you use a VOM to check the heater while you were replacing the plug? Put your meter on Ohms and you should see roughly 20 ohms across the two wires. Those cords do fail or it might just be unplugged at the block but the heater in the block can also fail. More troubleshooting definitely required.
 
#6 ·
Block heater part 2

OK, I did the OHMS test today, no movement at all, so I took the plug off I had replaced the old one with, still no movement, so can it still be just the cord that is bad, it sure was bad at the plug. or is the heater done, what do you think, do the heaters go bad, Thanks
 
#7 ·
OK, I did the OHMS test today, no movement at all, so I took the plug off I had replaced the old one with, still no movement, so can it still be just the cord that is bad, it sure was bad at the plug. or is the heater done, what do you think, do the heaters go bad, Thanks
Crawl under it and remove the cord at the heater and check for OHMS then you will know one way or another.
 
#10 ·
Thats what we are all here for...helping each other out. Not a bother at all.

So if I understand correctly, you unplugged the old cord where it plugs into the heater housing?

There should be two brass prongs in the housing and these are where you would place the two leads from the meter (one lead on each one). The switch on the meter should be set to Ohms and the screen should provide a value (which should bounce around a little).

I am away from my trucks right now or I would snap some photos.

If its difficult to see the recessed brass prongs while in the uncomfortable position under the truck then just unplug the old cord. Plug in the new cord. Run it out to the side of your vehicle where you can sit upright and have better ligght to see.

The new cord should not have any breaks in it since its new and so then touch the leads from the meter on the two prongs that you would typically plug into the wall (not the ground prong).
 
#11 ·
Not being a smart a$$ but did you check your ohm meter to make sure that it is working?

If not touch the two leads together, your meter should read zero

Sent from my SM-J737V using Tapatalk
 
#12 ·
My internet connection is bad right now so I will add more photos to this post later.

Check back.

This photo shows the location of the block heater where the cord plugs in (left side of photo).
 

Attachments

#13 · (Edited)
#16 ·
I am away from my trucks right now but mine had a clip as well.

I seem to recall there was also original threading that the clip just snapped right above but that I screwed onto with my new cord.

I wish I was home to confirm.
 
#17 ·
I found this image on the web which confirms you should be good to go.
 

Attachments

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top