The 120v AC "heater" came with 2 parts for 2005-2007.
The first 3 years, the car could add a block heater and HV battery heater together. In 2008 the battery heater option was discontinued for unknown reasons.

Your battery pack's usefullness starts to drop the colder it gets, and the drop becomes more noticable below 50'F.

However, using the battery warms it to the 70's and 80's ( from the 50's) pretty quick. HINT: don't let the pack fall below 50 by using it every day.

I use mine, and park it outside for my 12 hour work shift in 20 degrees and the pack is still 50'F after sitting 12 hours. The drive home warms it back up to the 70's. After sleeping 12 hours, the pack is down to 50. The pack is well insulated, so it can sit in sub-freezing for 12 hours and stay above 50 degrees inside.

No, I would probably NOT invest in a block heater for occasional 20's and 30's.
And the best way to heat the battery to gain full usefullness is to drive it longer than 15 minutes each day. The plug-in heater really only is helpful for those first 15 minutes.

Below is a graph of how temperature affects the battery current. Green = amps out, and pink = amps of charge.

 

Please pull the carpet from your cargo area and look to see if you have a connection to the hybrid battery heaters:
This 2008 vehicle does not have the connection:


This 2008 FEH does have the connection:


This is the internal view of the hybrid battery:


Hope this helps.

 

Okay, I checked the HV battery and I have the wiring connection for the hybrid battery heater//jump starter control. Do I still need to purchase the 3 parts previously stated or not?

 

YES--because you have a 2007 model.
FM6z10b689AA--wire assembly charger around $80
F5rz6a051b--heater asy around $36
4m6z6b018aa--wire asy around $68

I would only provide this information to a fellow Chicago resident --I used to live in Kane County but my roots are in the state north of you.

 

Thanks Billy. Now I have to get to a Ford dealership and wait for a reasonably warm day to come around again.

 

The shadow knows.....

When the engine/transaxle ECU firmware decides it's READY...!

 

John,

My 08 FEH does have a coolant temperature sensor. It is shown on page 303-14B-10 of my Shop Manual, and its part number is 8548 ECT sensor.

 

2005 to 2007 model years do not have a direct coolent sensor.
The water temperature is calculated based on cylinder head temperature.
There is a CHT probe, that runs, generally, 35-40 degrees hotter than the water.

It would be a little strange for them to put it on the 2008.
It is possible, but I'd like you to physically go out and look for it on your car.
Some pages have minor errors on them.

HTH,
-John

P.S. there are two separate coolant loops and 2 radiators, one for the engine, and one for the electronics.

 

Kephra(Bill), I have an 08 MMH and the service manual also. As I am becoming more comfortable using it, (searching for location on engine block heater etc), I have made a similiar mistake to what I think you have made here. Page 303-14B-10 shows an engine coolant temperature for a 3.0 Liter engine, not the 2.3 Liter in our hybrids. As I said, I have found myself looking at the wrong engine diagrams before also. Hope that helps.

Brian

 

Brian,

You are probably right, although I got to that page by following the troubleshooting guide for engine not warming up.

My car is exhibiting the symptom that it never heats up completely, as if the thermostat is stuck open. Full hybrid function seldom occurs. The scanguage fWT coolant temperature reading is totally erratic, often changing 20 degrees in a few seconds while the car is running. When the car has been parked for a while fWT and CHT agree within a degree or two. Also the scanguage fWT reading agrees with the car's built in diagnostics.

When the car is run, CHT gradually comes up and is steady and consistent. fWT also increases, but is erratic, and seldom reaches above 150 degrees. If coolant temperature is calculated from CHT, then it would not be erratic while CHT is constant, so I have a hard time buying that coolant temperature is computed from CHT.

Anyway, the car is going to the dealer tomorrow so the tech can have a looksee. I'll ask him about the sensor. I cannot believe that the car never warms up completely in 40 degree ambient temperatures.

Thanks,

Bill