texasram2500

I have 2006 Dodge and the last week when I leave my truck plugged in all night the wait to start light still comes on in the morning and it seems as though the truck is cold. I am assuming its a problem with the cord or element. Any ideas on how to troubleshoot so I know which one it is and how hard is it to change the element if that is the problem?

AH64ID

How cold was it? Was it windy? The block has to get above 66*F for the WTS light not to come on.

Did you verify the extension cord has power? Block heaters will trip GFCI's pretty easily.

Can you measure the resistance thru the block heater cord?

1-2-3

You can hear the block heater working. it will sound like an old coffee percolator. And the grid heaters coming on are based on air temp, not coolant temp, which is what the block heater is heating.

cdennyb

Use an ohm meter and check the element by touching the probes to the power terminals. You should see some resistance there. If nothing shows up you have an OPEN circuit meaning the element is the issue or the wiring to the heater element. Use an ampmeter to check the element if it passes the above test and see if it's drawing power. Probably a broken wire, those things are pretty bulletproof.

shep1

Mine did the same thing. It was the cord. Had a broken wire at the plug.

Shorts

With this extreme cold we've had here my WTS light comes on and stays for a good bit (haven't timed) before it goes out.

I just got my block heater cord attached last week and have used it this week. I had my truck plugged in overnight Wednesday. (DFW so location with the OP is about right). I go to start the truck Thursday morning and the WTS light didn't come on.


Can the block be warmed enough to heat the air in the under hood compartment that the grid heater doesn't cycle? The grid heater is right there on the block right?

Purplezr2

When you say extreme cold, what temps, If it is in the teens or 20's my truck the WTS light will not come on due to the head from the block heater. If it is plug in over night you can open the hood and feel the heat coming off the motor.

Shorts

Negative wind chills, single-to-20* temps in the a.m.

jhenson

I had mined plugged in all night last Wed, Thurs, and Friday and each morning when I turned the key the light immediately goes off and she fires like it's a summer day. If your block heater is working you will get steam off the head and block if water hits it . Accidentally left it plugged in one time and went out to install a new coat of clean on the ol gal and when I popped the hood to wash the motor...LOOK OUT!!!!!

AH64ID

Yes it can. It has to be VERY VERY VERY VERY cold and/or VERY windy to now allow a block heater to get the block and intake up to 66*F. The intake heats a little slower due to heat transfer but my block and intake are always within about 2* of each other in the morning, whether its been plugged in for 90 minutes or overnight.

Last few times I used the block heater overnight it was between -5* and 0* each night, and the block was 91-98* each morning, depending on the wind. Once the motor started it dropped to the low 80*s, but the WTS was off when I first turned the key on.

The WTS may not illuminate but the grid heaters are still working.


Remeber wind chill won't cool the block. It does help the block cool to ambient temps sooner, but the block/truck/etc can't cool off more than ambient.

How warm was it out? I have never seen my block get above about 110*, thou I don't plug it in overnight if its above freezeing out.

Shorts

Great info AH64ID - thank you.


Oh, I forgot to mention, the day I noted up there, I started the truck and idle was normal. About a minute or two later high idle engaged.

What is the relationship between (high) idle, the grid heater and temps?

AH64ID

The auto fast idle will kick in as follows..

~32*F and lower the rpms will ramp up to 1,000 after 2 minutes of uninterupted (thorttle, gear, brake, etc) idle and the coolant is below 200*. This will also happen after driving for a while and the intake air temp and ambient temp are below freezing.

~15*F and lower (I have seen it happen as high as 23*F), the rpm's will go to 1,000 as soon as you start it.

The WTS light will happen anytime the ambient/manifold temps are below 66*F. The duration is temp dependant. After start the grids will operate for apporx 120-150 secons, or until you reach 18 mph.

texasram2500

Thanks for the replies. I am in the DFW area and we have been having upper teen to low twenties for several nights. I used a different extension cord last night and different outlet. Made sure I had power and I am sure the block heater is not working. I'll mess with the cord tomorrow since it is finally going to warm up enough to wash and change oil.

Shorts

We're suppose to be warming up into the 70s next week!

johnh

mine works perfectly, but it is silent