I have traced a parasitic draw on my battery to the Blower Motor Resistor Assembly (BMRA).
It pulls power from fuse #51. The draw was 0.07 Amp with fuse 51 in place and 0.004 Amps (4 mA) with 51 removed.

The number on the existing, what looks to be original, part is 12135104.
It is my understanding GMC bought ACDelco so that is their go to supplier.

On the ACDelco site PN 12135104 does not exist.
By a vehicle search I found PN 15-81796 and it has the appearance of the existing.
The dealer is selling a part with wish washy specs supposedly ACDelco for $127.44.

I'm finding other aftermarket manufacturers:
DWD
Dorman
Duralast
AA Ignition
with pricing from $13 up to $68

and $52 for an ACDelco PN#.

Is anyone able to weigh in on aftermarket manufacturers of a BMRA?

 

Please, always check RockAuto parts, I have been happy with them.
http://www.rockauto.com/en/catalog/c...+resistor,6557

 

I have a parasitic draw on my battery.
I found it going thru fuse 51. I can only find that fuse 51 feeds the HIGH speed of the blower.

I did a desk top continuity test of BMRA and do not see anything I identify as a short. (?)
See Image Below.

I assume that to have a parasitic draw thru the BMRA it would have to have a short in it feeding power to ground.

Anyone see what I am missing?
Could this mean there is a short in the r/blk wire from fuse 51 to the wide connector?

Since the blower motor is feed by the BMRA could it short without the BMRA? ... clutching at straws

 

You might try unplugging the blower motor see what that does.

 

a short before the load would blow the fuse. there are no other loads on the circuit so replacing the resistor is where i would go.
When it comes to certain parts i would go oem...a blower resistor is not one of them.
a/c delco is not oem for gm. gm is who gm uses for oem...delco is what gm uses for their low cost line of parts.

 

tech2,

How do you get to that conclusion? See Image Below.

I can understand that for a BMRA OEM is not critical.
I could still benefit from experience on alternate sources.

 

FWIW, Rock Auto has the "OEM" notation next to a lot of AC Delco parts. And on the ones I've checked, the part numbers match up with GMPartsDirect.

 

i worked at a gm dealer ship....the oem parts that came with the car were not branded delco. the delco advantage line were the cheap line of parts they sold. quote out a rear drum for a 07 pick up...oem drum is $400..delco advantage is $150 but will need maching before put it on...cause its ****.

 

Replacement Report

An aside, in looking for information I see the BMRA seems to burn up and cause the fan to run constantly. That consequentially burns out the battery. I never noticed that the blower was ON after the engine shut down ... if it ever was. I always turn the fan and environmental controls OFF when I leave the van but the BMRA was somehow drawing 4 amps without anything ON. It was not the case for me, but on some vehicles there is something wrong with the wide connector and that needs to be replaced too ... look for burn marks.
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I could not find a replacement part that looked the same as the original P# 12135104.
Ended up purchasing the Dorman, P# 973007 ... Made in China ... just sayin ... for less than 1/2 an ACDelco part.
I cross my fingers that I do not regret it.
I confirmed the ACDelco was the same configuration.

Dorman, P# 973007 is not a direct swap (exact fit} with the original. The mounting holes and connectors match up but the slot in the evaporator housing does not accommodate it. I checked for parasitic draw with the new part connected and it was 0.0 Amp.

I made a template of the hole needed in the evaporator housing and cut it out with a hacksaw blade, finishing up with a file.

 

Good work. Keep us posted on how well/long it works.