Looking for 2012 5.3 liter E38 Connector Pin Out

**pmkls1** · 05-02-2014

Dave,

I BELIEVE that you are correct about how the ECM controls the fans and that is why your wiring and test results support your theory. That was how I understood the system to work going by the schematic and my memory. I did have a concern about you being able to find diodes that were rated to support the current that the system carries, but your initial test results indicate that the diodes you are using are adequate. Congrats on your success so far and the pics of your wiring look good ! Those diodes in your pics look like the ones I recall seeing more prominently than the A/C system diodes I dug out of my toolbox. Notice that on top of the diodes you have they have the symbol for a diode on them and the pics I posted earlier had a 1.0 on the top of them. I have a drawer dedicated to relays and fuses that I stripped from fuse blocks that I replaced (which happens quite often) and was sure that I had one. But, I could only find the A/C diodes.

**1project2many** · 05-02-2014

I looked at the posted wiring diagram. The diodes appear to conduct current back through the motor as it winds down after the relays open and stop supplying power.

**dave w** · 05-02-2014

Originally Posted by 1project2many

I looked at the posted wiring diagram. The diodes appear to conduct current back through the motor as it winds down after the relays open and stop supplying power.

I was thinking the diodes were for spark suppression when the relays open. I agree the cooling fan motors provide a path to bleed off excess current / spark.

dave w

**brian617** · 05-02-2014

Originally Posted by dave w

I was thinking the diodes were for spark suppression when the relays open. I agree the cooling fan motors provide a path to bleed off excess current / spark.

dave w

Thats how interpret the diagram as well. The diodes are wired similar to an AC clutch. The windings in the fan motor would reverse a voltage surge back towards the relay causing bad things.

**dave w** · 05-03-2014

So I just learned the 2009 Wangler has ONE radiator fan. The new question is how to set up the E38 for ONE fan? Maybe having the green wire grounded all the time, without the fan motor wiring is an option? I don't think there is an option of ONE fan in the E38?

dave w

**dave w** · 05-03-2014

I'm going to look at the possibility of using a Corvette PWM controller (GM # 10377609) as an option for controlling ONE fan. I'm thinking I should be able to copy paste the E38 computer fan parameters from a Corvette into the current flash.

This fan setup change is a classic case of poor planning.

dave w

**JeepsAndGuns** · 05-04-2014

Is that simply a pwm relay, or are there electronics in it that talk to the pcm?

**dave w** · 05-04-2014

Originally Posted by JeepsAndGuns

Is that simply a pwm relay, or are there electronics in it that talk to the pcm?

I like your thinking ... It could be a simple PWM relay. I don't know enough about the Corvette fan PWM controller or the E38 computer to reverse engineer a solution. I'm doing this conversion for a customer, so I need to use "Off the Shelf" parts. The term "Off the Shelf" could mean most any automotive OEM / Aftermarket part. If something should fail, a replacement part should be available from the normal "Automotive Parts" sources.

I found information that Tyco offers a 30 amp Mini 280 SSR, same size relay I have in the dual fan module.

dave w

**JeepsAndGuns** · 05-04-2014

I know we are always looking for off the shelf/junkyard parts to use on conversions. I was thinking if this was a simple pwm relay, it might be a affordable one that might be good for conversions. But after looking into it, it appears to only be used on the 05 and up vette, and 04-09 caddy XLR. It also appears to be quite spendy ($120 from rockauto, which us usally the cheapest)

**dave w** · 05-04-2014

Originally Posted by JeepsAndGuns

I know we are always looking for off the shelf/junkyard parts to use on conversions. I was thinking if this was a simple pwm relay, it might be a affordable one that might be good for conversions. But after looking into it, it appears to only be used on the 05 and up vette, and 04-09 caddy XLR. It also appears to be quite spendy ($120 from rockauto, which us usally the cheapest)

The connector used for the PWM module is impossible to source! I failed with Google to find the connector part number. Bottom connector in the attached picture.

One option I'm considering is to solder terminated wires directly to the PWM module and fill the cavity with clear RTV or something similar. Not a good option for easy replacement in the event of a failure. There are aftermarket fan assemblies available for slightly less than $110 (without PWM module) with the connectors ready to plug into the PWM module. Used (complete) fan assemblies are not low cost, found one on ebay for about $150 ( + buyer pays actual shipping). Searching the local salvage yards came up empty.

dave w

**JeepsAndGuns** · 05-05-2014

Being a vette only part is going to make it pretty much a no go for finding one in a junkyard. Can the connector not be gotten through a GM dealer?
I'm guessing the connector is specific to that module only?

**dave w** · 05-05-2014

Originally Posted by JeepsAndGuns

Being a vette only part is going to make it pretty much a no go for finding one in a junkyard. Can the connector not be gotten through a GM dealer?
I'm guessing the connector is specific to that module only?

The Cadillac XLR uses the same fan assembly / module as the Vette. I don't think the GM dealers can get just the connector, because the connector is included with the fan / shroud assembly part #15819952.

dave w

**pmkls1** · 05-05-2014

There is a possibility of getting just the connector body, but obtaining the part number would probably be easier through viewing the wiring schematics. If you view the portion of the schematics that portrays the pinout location it gives you a part number for the connector body and also your terminal part numbers. The terminal part numbers are not in the typical parts system, but the connector part number usually is if it is available. If there is much chance of getting the connector, it would be either that way or speaking to a parts guy and seeing if the parts catalog lists a number for that harness assembly. The actual parts catalog does list far more than you can find online so there is at least a chance. Your best bet would be to physically go to a dealer parts department and look at the parts fiche with the parts guy.

HTH,
Phil

**1project2many** · 05-05-2014

I think I've seen a version of that connector on Mercedes fans. Might also be used on Chryco products. Is that connector the correct one? Four pins?
Have you looked through these?
http://www.bosch-connectors.com/bogscoca/category/1

These might be right...
http://www.bosch-connectors.com/bogscoca/category/7

**dave w** · 05-05-2014

Originally Posted by 1project2many

I think I've seen a version of that connector on Mercedes fans. Might also be used on Chryco products. Is that connector the correct one? Four pins?
Have you looked through these?
http://www.bosch-connectors.com/bogscoca/category/1

These might be right...
http://www.bosch-connectors.com/bogscoca/category/7

Thanks for helping me look for the PWM connector!

Attached is a better picture of the actual part, showing the side latching tabs.

dave w