Hi all, new to the forum, first post. I've searched for this and couldn't find it, please direct me if I'm wrong.

I have a 2009 HHR whose blower motor quit working. After much troubleshooting it appears the relay socket connections on the Body Control Module (GM Part Number 25928052) circuit board are likely cracked (traces and/or solder joints). I came this diagnosis by first replacing the relay, which fixed it for about an hour. Then "twisting" this relay with my hand while socketed with the car is running; the fan works and often stays on for long periods, but it always stops again and requires more relay "twisting".

So, I got the aforementioned BCM out (pain!) and in classic "new car" fashion, it's not made to be worked on. I'm pretty certain all I need to do is heat up some solder connections. Looks like to get the Circuit Board out of the case I need to drill-out two threaded fasteners' fanged ends; i.e., GM "flared" one end of the two pass through threaded inserts, further holding the case halves together.

So:

Anybody been here and got some good suggestions?

Any good hacks?

If I get a new replacement ($150 Amazon, AC Delco) will a dealer need to program it, or is it plug and play?

Help me Mr Wizard!

 

Welcome to the site

Maybe the contacts that the relay pins slide into are spread out.

The correct way would be replacement but you could try putting some solder on the pins of the relay and build them up a little thicker for better contact.

 

Appreciate the tip, thank you. Don't that's it though, based on the "tracks" left on both sides of the relays pins, left by the tight contact with the metal socket contacts. Later today I'll drill out those clamping pass through, threaded tubes to get the case off and have a look at the circuit board, nothing to loose at this point.

 

Welcome!

How did it get damaged? It is pretty well covered up and not much reason to fiddle with it. I don't remember having to, I've only looked at the BCM once to know where it was.

I would be absolutely sure the resistor is good.

 

Found the root cause. It’s a “factory defect” electrical connection that created too much electrical resistance. Over much time, 6 years and about 80K miles, it has finally failed.

The back side of the BCM had a large white plastic housing with multiple female electrical connectors embedded (Delphi <PA66>). One these female connections mated with a male connector from the BCM that fed pole #30 of the HVAC relay (also named #30, HVAC). After I removed the BCM circuit board from its case I noticed heat damage on both ends of this metal conductor that passed through the circuit board, especially the male prong. When I looked at the white plastic housing with multiple female connectors, the one that supplied current to pole #30 of the relay was burnt black and partially molten; the metal showed significant heat damage too.

Looking at the schematic in my Haynes manual, and based on my use of the car, it appears the sole function of the relay is to disallow the blower motor from running when the Fan Speed Control on the console is set to on (anything but off) and the Key is not in the ignition, and set to axillary or run. In other words, it keeps you from running down the battery if you were able to leave the blower motor on and walk away from the car for an extended time.

I propose this cheap fix: bypass the relay and always remember to turn the blower motor off with the Fan Speed Control on the console before I leave the car. This would involve identifying the two wires that Relay #30 HVAC, connects; both are on the Delphi <PA66> connector, cutting them and soldering them together.

Hope I haven’t fried the BCM with static electricity while out of the case. 

What do you all think? Am I missing anything? Anyone have a better idea? Please let me know.

 

You propose to "hot wire" the fan so it has power to that circuit all the time ?

Wow. Uh, no way. Just asking for trouble there. You should fix it correctly.

 

Can you connect wiring to take the relay off the board? It's a pretty common thing to do these days. Wired sockets are available for the 5 terminal cube relays or solder the wires to the relay as you seem to be comfortable doing it.