Prius Mods part 3.4 – DEFA SafeStart finally installed!

I have finally installed the DEFA SafeStart permanently.  We left the story at Prius Mods part 3.3 – DEFA SafeStart WarmUp cable installation with the cable attached to the coolant overflow bottle with a cable tie.  To warm the engine I had to open the bonnet (hood) to fit and remove the power cable.  Not ideal.

I just finished fitting a lower grill block (See Prius Mods part 4 – later) when I decided to fit the cable once and for all.  I was going to have to find a way to route the cable from the upper grill (necessitated by blocking the lower grill) to the EBH.

Note: The official DEFA fitting instructions for the Prius put the socket in the lower grill, but don’t indicate how to route the cable.  My  method doesn’t leave much slack in the cable, but it isn’t stretched.

DEFA Connector Cable with fasteners. Note that “A” will be on the outside, there’s no O-ring and fastener “F” will be fitted backwards.

Step 1: I had to remove cable from EBH.  Fortunately, I could reach over the engine and down to the back of the block to remove the cable.  YAMV (Your Arm-age May Vary)

Tools: Pliers, Kincrome panel levers, Supatool 10mm socket with ratchet handle and ratchet wheel, pearl catch
Pop panel pins to remove cover. There’s 9 more pop pins and two bolts hiding under here.

Step 2: Remove the 3 pop pins and the front cover.  Underneath you’ll find 9 similar pop pins and two 10mm bolts holding the top of the bumper in place.  When finished, you should be able to separate the front panel far enough forward to slide your arm between the radiator and the grill.  If not, get a small urchin to help you.

Some things unclip to make replacing a headlamp bulb easier/possible. For this job, remove the lot.

Step 3: Make space.  Remove this lot and you’ll have adequate.

  1. Unclip the hose from the coolant overflow bottle (not shown)
  2. Remove the 2 x 10 mm bolts from behind the airbox
  3. Remove the 10mm bolt holding the airbox and clip
  4. Unclip the hose from its bracket
  5. Remove the airbox by twisting slightly and pulling to the left to separate it from the air-cleaner housing.

Step 4: The socket will not fit through the grill, so you’ll have to feed it in from the outside.  Fit part “A” (three pins facing out) to the cable.  Slide the cable into the grille; it will bulge a little.  Feed part “F” backwards, so that the thread will register, and tighten.

Step 5: Finding the gap around the radiator is not easy.  You think you’ve found it and then you’re blocked by a plastic bracket in front of the radiator.  Hint: Lift the inverter coolant (?) hose and feed the pearl catch or similar tool through the gap.

Looking from the rear – The gap between the radiator and body is just big enough for two

Step 6: Attach the cable to the pearl catch and gently pull the cable through the gap.  I used some 13mm pipe insulation to protect the cable.  A bit of fettling and it’s in place.

Cable run, protected by 13mm pipe insulation passes over an A/C line and the engine mount.  Earth lead is temporarily taped to the negative charging terminal

Step 7: Run the cable down the right-hand-side of the engine. (“Right” as seen from the rear of the car.)  I used another length of pipe insulation to “attach” the cable to the engine mount.  Note: Check as you go that you aren’t twisting or stretching the cable.

Step 8: Attach the cable to the EBH.  I could do this by reaching over the engine from above.  Hint: The earth cable is at the bottom of the plug and should line up to the bottom of the socket on the EBH.  Of course, you can always see better from under the car.

Step 9: Put everything back where you found it.  Note: I use the 10mm bolt that attaches the airbox to the engine mount to attach the earth lead.

DEFA SafeStart socket mounted in the upper grill – Prius NVW30


2 thoughts on “Prius Mods part 3.4 – DEFA SafeStart finally installed!

  1. I just bought a new Toyota Prius Plugin. In Norway it is often could in the morning. So I bought it with a DEFA Engine Block Heater. Since it is a plugin, the charger cable is allways connected when the car is parked. Is there any reason why I need an addisional power cable for the DEFA? It would have been most convinient with only one cable. Since the power outlet is normally on the wall a couple of meters behind the car, I need an extention cord for the DEFA.


    1. Velkommen Kjell
      A DEFA EBH is a perfect option for a PiP (Plug-in Prius). A warm engine does not need to start at all!
      I am saving for a PiP conversion, so I had the same question. If my DEFA socket is at the front and the plug-in socket is at the rear, which way do I park the car?
      Here are my thoughts…
      1. If you must have 2 cables, move the DEFA socket closer to the Toyota socket, perhaps to the rear bumper. That would make plugging and unplugging a little more convenient.
      2. Following on from 1., you could add a MultiCharger to the 12V battery (and Termini heater) to the DEFA EBH. Because you would have to run the cable to the rear anyway, moving the DEFA socket to the rear bumper makes sense.
      3. DEFA could make a special cable that would interface with the Toyota PiP socket. So one cable could power both.

      A few issues!
      a. Do you always want EBH + HV battery charging on at the same time? You would need to add the SmartStart timer. Otherwise you will be warming the engine all night.
      b. Will there be enough space in the sills to carry the DEFA cable to the back?

      The biggest difference between DEFA EBH and the Toyota Canada EBH is how beautifully integrated the DEFA system is. I suggest that you contact Bjørn at DEFA because I’m sure that they would love to have an integrated solution to work with the PiP. (Are Canada and Norway ice hockey rivals?)
      You are lucky, you can drive your car to DEFA to show them the issue exactly.

      Please keep in touch.


Comments welcome

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.