R107 SL Heater Blower Motor Cover

Here we give you the lowdown on what should be a very simple and inexpensive part… but this is one that can lead to a major disaster if left for too long.

What is it?

This is the plastic cover (or lid) which sits above the heater blower motor, suitable for all R107 SLs with or without air conditioning. It replaces OE part number 1078300352.

Where does it go?

The blower motor sits beneath the plastic blower motor cover (or lid), inside a chamber within the bulkhead, at the back of the engine beneath the windscreen. 

There is a rubber seal that mounts to the bulkhead which the blower motor sits on top of. Above the blower motor, the plastic blower motor cover (or lid) also has it’s own rubber seal.

This area is a well known weak spot for the R107 SL. 

Why do I need it?

The original Mercedes-Benz items from the 1970s and 80s are made from a plastic that turns very brittle. After years of consistent heating and cooling as the engine heats and cools, the heater blower motor cover and rubber seal begin to fail. Once this has happened, water can get into the chamber and down inside the bulkhead. Not only does this slowly damage the blower motor, but starts to corrode the car from the inside out. 

A faulty blower motor could be noisy, erratic, spontaneous or simply not working. Rust within the bulkhead would explain damp carpets and a musty smell in the cabin.

Our redesigned unit is made from a modern plastic that will stand the test of time. Not only is our version more hardwearing than the original, but through rigorous testing these units have proved themselves to perform within 3% of the genuine Mercedes-Benz units air flow, making this the popular replacement choice for SL 107 owners.

Fig 1: Actual panels taken from customer cars

Below you can clearly see the damage that a leaking / defective blower motor cover can do. This is inside the chamber where the blower motor sits, and no R107 SL is immune from this, even the later cars are susceptible to it.

What are my options?

There are 5 products to think about when addressing this area of the car:

Blower motor (our part number 107.1180)

Blower motor seal (our part number 107.0331)

Blower motor cover (our part number 107.0289)

Blower motor cover seal (our part number 107.0746)

Blower motor resistor / control unit (our part number 107.0147)

We always recommend the complete bundle deal.

How do I fit it?

It is simple to fit and replace the blower motor, cover and seals, however we would advise a thorough check for rust and corrosion whilst the motor is removed. 

The SLSHOP are renowned for work with the bulkhead of the R107 SL. Be sure to watch our video on R107 Bulkhead Corrosion. Contact our team to find out more.

What else do I need to know?

The blower motor cover seal is a very small part relative to the damage that a failed seal can eventually cause. Once water has reached the unprotected metal inside the housing where the blower motor lives, there is very little to stop it causing huge amounts of damage to the car from the inside out.

Understanding the condition of this area on your car is vital to the long term enjoyment of your SL.

If you are unsure about any aspect of the blower motor / bulkhead area of your SL, please contact us.