The climate control blower motor is not working on any speed in my '95 960 wagon. Fuse is good. Pulled the cover off under the dash to get to the blower. All connectors that are obviously visible seem to be tight. There is what appears to be a relay located on the right side of the center console marked L203. It has 6 lugs marked 15, 31, 31b, 86, S, and I. Without a wiring diagram not sure if this controls the blower or not. Anyone have any ideas?

 

Check this post out that I put of a few weeks ago, it might help a lot

https://volvoforums.com/forum/volvo-...-bypass-83147/

I would pul the plug from the blower motor and test to make sure there is voltage, if there is non, its most likely the blower resistor. I found a place with them pretty cheap iRollParts | New Genuine Volvo Parts & Accessories $150 for mine, OEM straight from Volvo...AutoZone wanted to charge me nearly 300! and ebay was even worse.

 

Thanks for the suggestion. No voltage at motor so used the 20 amp resistor fix and the motor turned over very slowly and then died. Suspect the motor is bad and it fried the resistor. Will look into a motor and resistor to fix the problem. Thanks again.

 

Thats a common problem, The bearings on the blower motor start to fail and it increases the electric load on the resistor. Eventually they both fail. Glad I could help, good lick with your repair.

 

I think with ECC it's not really a resistor, but a transistor. Can you take it apart and have a look?

 

This is a fact. In fact its the toshiba 2SD1512 4k transistor to be specific, and if you have soldering skills and can find a compatible one then I would give it a go. The specific transistor in question is no longer in production.
Typically they still call these items "resistors" even though you are correct on the ECC version they are the transistor. They sometimes call them "Controllers" Or "Control Panel"

 

2SD1512 seems to have a usual collector current of 20mA, not strong enough to drive the blower fan. Maybe this one drives another transistor?

If there are multiple transistors, it should be easy enough to find out how far the "PWM" signal from the ECC is getting, just 'scope the bases of them. Probably a meter set to AC volts will be useful for this if an oscilloscope is not available.

As far as transistors go, it's not difficult to find suitable replacements. Of course the transistor package should fit, and the terminals should be arranged the same. Then, look for ratings including Vceo, Vebo, and Ic to be equal or greater. The 2SD1512 has a Vebo of 15V, making it suitable to directly drive the base with battery voltage.

If anyone finds a transistor and wants to know whether it's a good idea to try it as a substitute, I'll be happy to help.

 

I would be really interested in getting a compatible transistor if you find one. I replaced the whole controller assembly because I did not want to mess with it as the Texas heat starts to rise.
So I have the old one and I confirmed that the transistor is bad. I checked all the caps and I ohm'ed out all the traces, all else looks good.

 

Mouser has STL73 (their number 511-STL73) Do you see anything wrong with this one?

I chose this by limiting parameters to higher Vebo since this is the most remarkable feature I saw about the 2SD1512. Beta (Hfe) is not as high but it will probably work. The terminals are arranged E-C-B as on the original.