Do-it-yourself repair B21 DF71 starter motor battery decoupling relay locked

  7
 September 3, 2024

The later version of W207 was launched at the end of 14. Currently, it is about 83,000 kilometers away, and the Fugui Lamp lights up without warning

Yuan Zheng read the code, and for some reason the direction column was locked. This is a rhythm that costs money.

Later, the problem of adjusting the steering wheel up and down was solved without cost after I thought about it, saving a lot of effort. Otherwise, I would have to remove the steering wheel, remove the instrument panel and replace the motor to carry out maintenance.

Start from a simple start, read the code and point to the rear SAM, first check the battery relay behind, and rule out that it’s not it.

Auxiliary battery relay close-up, it’s good

According to the WIS circuit diagram, point to decoupling relay F32K1 in fuse box F32, open and remove all cables at the bottom of the battery battery, the steel plate at the top of the fuse box, and 7 sets of wire harnesses at the bottom of the bracket fuses of the box. Remove the fuse box assembly

Remove the battery, remove the battery bottom plate, use T50 plum blossom, three screws

When installing it back, a screw between the battery bottom plate and the firewall was interfered with by the sink. It was very difficult to screw it back. I worked hard to do a miracle. I opened the sink a little and tried to screw it in.

Removed battery

Fuse box close-up

Remove all wiring harnesses

material number

The difficulty is to remove the hanger, pry open the protective plate behind the fuse box, and remove the seven sets of cables at the bottom

Take photos and remember the cable sequence before dismantling

photodocumentation

Pay attention to cable fixing details

Remove the box and pry open the box

What broke was this black relay

Taobao, Beijing and Guangdong have many car dismantling accessories

Considering that the service life of the second-hand part is unreliable, after inquiry, it was found that the failure rate of the part was quite high and it was very difficult to remove it once. I directly placed an order for a brand new original fuse box assembly.
There is no supplier providing this accessory in Shanghai, the most recent supplier is in Wuxi
There are cheaper suppliers in Beijing, with a difference of about 300 yuan. It is too far and time-consuming, so I won’t consider it.

Contact the shipper and ask Lala to send straight hair from Wuxi to Shanghai that morning

The parts arrived in my hands in less than two hours, and the high-speed freight fee was less than 300

The original factory smells so fragrant

Original parts packaging

in the garage.

Repairs in the order of dismantling the next night and reverse

The new assembly is on board

The fault was perfectly resolved