EEVblog Electronics Community Forum

Electronics => Repair => Topic started by: buckwheat on August 19, 2022, 03:26:21 pm

Title: Help identifying and locating resistor
Post by: buckwheat on August 19, 2022, 03:26:21 pm
I am trying to identify this device (WSR-2). From my research, I believe it is a current sensing resistor. It is on a Magneti-Marelli ECU last produced around 2000. Any help is appreciated!
Title: Re: Help identifying and locating resistor
Post by: mariush on August 19, 2022, 04:07:15 pm
If it's same as the other on the right, it's Dale WSR-2 series resistor , 0.649 ohm 1%

wsr datasheet : https://www.vishay.com/docs/30101/wsr.pdf (https://www.vishay.com/docs/30101/wsr.pdf)

marking  : https://www.vishay.com/docs/30327/pms-pmpmarking.pdf (https://www.vishay.com/docs/30327/pms-pmpmarking.pdf)

2 is most likely 2w rating
Title: Re: Help identifying and locating resistor
Post by: buckwheat on August 20, 2022, 03:59:54 pm
Thanks for that, I ordered a replacement and I'm going to attempt the repair. Do you know what coating would be applied over the top of this? I can't tell if it is a spray or brush on, it has a tacky feel to it.
Title: Re: Help identifying and locating resistor
Post by: mariush on August 20, 2022, 04:06:23 pm
No idea, but you should also figure out why it blew in the first place .. check for shorted mosfets, diodes that are open both ways etc
Title: Re: Help identifying and locating resistor
Post by: wasedadoc on August 20, 2022, 06:08:58 pm
Quote from: mariush on August 20, 2022, 04:06:23 pm
No idea, but you should also figure out why it blew in the first place .. check for shorted mosfets, diodes that are open both ways etc
+1.  There has been a lot of current through that resistor.  It didn't just fail all by itself.