RV Repair: How to Replace a Block Heater Cord

  • 1-3 hours
  • Intermediate
  • 25-75
What You'll Need
Replacement power cord
Adjustable wrench
Solder and soldering gun
Voltage meter

When doing RV repair on a block heater, you will want to consult your owners manual for replacement part details. The block heater consists of a power cord that plugs into your home or shop outlet, an electrical conduit box and the heat block. Each type of diesel RV will have a block heater to help the engine start on cold mornings. The power cable itself will either plug into the heater coil like a socket, or have to be screwed, or soldered into the unit by hand. New block heater units will require less work as they utilize the socket system to make replacing power cords easy.

Step 1 - Follow Electrical Safety Procedures

When ever you are dealing with electrical switches or circuits during your rv repair, always remember to secure the vehicle from moving and disconnect the negative poles on your battery to avoid electrical shock or feedback. This will also protect you from shorting out the vehicles electrical system, causing you further problems.

Step 2 - Remove the Old Power Cable

The first step in this type of rv repair is to remove the old cord from the system. If your cord is a socket one, then it will simply involve taking the old one out and plugging a new one in, there is generally a socket latch or clip. Push the clip in and pull on the actual socket end of your cord, not on the wires themselves. You can also wiggle it a little to get it to come loose, but be sure to apply pressure to the pin so it will let go. You can use a screwdriver if it isn't moving in enough to come free. This is built into the socket on the side to help prevent it from getting pulled out of the heater unit, if the cord gets tripped on.

If your Block heater cable is not a simple plug in unit, you are going to get a little deeper into your rv repair by removing the heater coil or circuit to get to the wires, where they are screwed into the main board.

Step 3 - Replacing a Power Cord Manually

A manual heater coil power cord that needs to be manually replaced is not a very difficult rv repair. Simply take your tools and carefully remove the heater unit from the heat block on the side of the engine. Once you have done this, you will see where the lines are connected to the coil on the inside. Again this varies by the unit, you may have to remove solder and solder them in, however most are simply screwed in with securing bolts. The positive and negative poles should be marked on the board, if not be sure to color match them as you take the old wires off the unit. Once you have replaced the old cord with the new one, you can then reassemble the heater unit to the heater block, reattach your negative battery pole and fire it up.