How to wire up a NP 236 in place of a 136.

[Captn. Crunch]

Yes you need to pull the parking brake pedal assembly. I have nothing to add as to the speed sensor wiring. Sorry

[Snowgeek]

Ok so I am wanting to get stared on this project but I am concerned about the amount of time it will take.... especially if I run into issues. So my question is is there a way to to divide this process into two parts (wiring and t-case install). Can I install the transfer case or do the wiring then drive it until my next window of time to work on it?

If so which one would you suggest to do first. I would rather do the wiring second as it would allow me trouble shoot the wiring right after I have done it.

Clearly I know that awd wouldn't work.

Thanks,

Ryan

[Captn. Crunch]

Do the tc swap and pull the AWD fuse until you're done with the wiring

[Snowgeek]

Great thanks! With a business two small kids and an endless array of house chores splitting this up will be great.

Any need to disconnect front drive line without the blazer drive line disconnect?

Ryan

[racrx7]

Only the last link worked, so I cant really determine what your asking. I do know GM liked to change wiring colors around between model years for the same components. I don't why, maybe to discourage DIY's. But the components are the same and usually laid out the same. What year is your van? And what year donor vehicle are your components from? It really shouldn't matter to be honest. All your TCCM is looking for is equilibrium of the two axle speeds. BUT, if it makes you feel better, go with the wiring colors of the donor TCCM. Either re-pin them at the TCCM connector, or possible just reverse the two plugs at the transfer case itself. If you can shoot me the two diagrams you were trying to post, Ill take a look at them and see if it really matters.

As for your front drive shaft? You can leave it in place. Until you get it wired up and functioning, the front and rear shafts will find equilibrium by slipping internally via the clutch pack. Make sure you ONLY use GM autotrac2 fluid in your fill.
Cheers,
Andre

[Astrophysics]

Hi,

Very nice 4x4 set up. Thank you for the info.'

AP

[Astrophysics]

Are you happy with the quality and performance of your head lamp replacement and turn signal modules?
What is manufacturer name and PN? They look interesting. A combo of LED and HID?

Thanks.

Do you remember the old British electrics?

Joseph Lucas
master of darkness
And Joe Lucas says " don't drive at night.

[racrx7]

Are you happy with the quality and performance of your head lamp replacement and turn signal modules?
What is manufacturer name and PN? They look interesting. A combo of LED and HID?

Thanks.

Do you remember the old British electrics?

HAHA, good ole Lucas electronics

As for my head lights. Well, I didn't find out until I got them that I discovered they were NOT true projectors. Its just a projector type looking lens that sits directly in front of the bulb. Unfortunately, the light output with stock bulbs is not as good as the factory headlights. I'm trying to find a brighter bulb to replace the stock ones to see if that improves light output. Don't get me wrong, it's drivable at night, just not what I was hoping for. They are sold by the brand name Spyder. They don't recommend the use of HID bulbs in them. Probably because the beam cut off pattern is incorrect and will blind on coming drivers. True HID lights, in automotive use, use a special shutter for the proper beam cut off, along with a true projector housing to focus the beam.

Cheers

[curtperry]

Hi, new member here, been lurking and soaking up the knowledge. Many thanks to captn and racrx7 for putting this together, especially the diagrams.

A few months back after I lifted and threw on some 31” tires I burnt up the 3-4 clutches in the 4l60e. So I decided while I was rebuilding the tranny I would take the opportunity to swap in the np236. I have it done and working. It's in a 2005 astro and everything works except the shift points in 4lo. I have not run the line for the 4lo signal to the ECM because it doesn't have the same pinout as the 2003 diagram shows here.

I've looked for factory manuals to buy or download and no luck. Can anyone point me in the right direction? I was thinking of a junkyard trip to find 2005 ish GM vehicles that have the same style ECM connectors and have 4lo. Thoughts?

[racrx7]

Hi, new member here, been lurking and soaking up the knowledge. Many thanks to captn and racrx7 for putting this together, especially the diagrams.

A few months back after I lifted and threw on some 31” tires I burnt up the 3-4 clutches in the 4l60e. So I decided while I was rebuilding the tranny I would take the opportunity to swap in the np236. I have it done and working. It's in a 2005 astro and everything works except the shift points in 4lo. I have not run the line for the 4lo signal to the ECM because it doesn't have the same pinout as the 2003 diagram shows here.

I've looked for factory manuals to buy or download and no luck. Can anyone point me in the right direction? I was thinking of a junkyard trip to find 2005 ish GM vehicles that have the same style ECM connectors and have 4lo. Thoughts?

Congrats and welcome to the NP236 TC club
Hmmm, are you referring to the ECM not having the same pinout? I coulda sworn there was no difference between '03 and'05. But I could be mistaken. Look at this link below, and scroll down to the 2003-2005 C2 connector of the PCM harness. Pin #16 is the 4WD low signal wire. Yours is different?

http://www.autozone.com/repairguides/Av ... 3f8025ecb2

[Stroverlander]

You can internet search 'gm esi download'...

[curtperry]

Congrats and welcome to the NP236 TC club
Hmmm, are you referring to the ECM not having the same pinout? I coulda sworn there was no difference between '03 and'05. But I could be mistaken. Look at this link below, and scroll down to the 2003-2005 C2 connector of the PCM harness. Pin #16 is the 4WD low signal wire. Yours is different?

http://www.autozone.com/repairguides/Av ... 3f8025ecb2

The 80 pin connectors shown in that link seem to be a match for mine, Mine are blue and green and shaped like the drawings show there. So Connector 2, Pin 16 may be the one!

I was looking for a couple hours and couldn't find the pinout info, just didn't know where to look!

[curtperry]

You can internet search 'gm esi download'...

Thanks for the tip. I have a 4GB download going right now. I have no idea what's in it but I like surprises.

[racrx7]

[quoteThe 80 pin connectors shown in that link seem to be a match for mine, Mine are blue and green and shaped like the drawings show there. So Connector 2, Pin 16 may be the one!][/quote]

It should be the right one. It will of course be empty on the connector in your van. I just pulled a spare pin from an old harness, along with the wire on it, disassembled my 80 pin connector and installed the scavenged pin. Then connect that wire to your TCCM.

[curtperry]

It should be the right one. It will of course be empty on the connector in your van. I just pulled a spare pin from an old harness, along with the wire on it, disassembled my 80 pin connector and installed the scavenged pin. Then connect that wire to your TCCM.

That's what I was thinking, would have to find a pin and attached wire to throw in there from the junkyard. I had considered opening up the ECM/PCM/whatever and tracing that pin and soldering a wire onto it, then making a new hole in the housing, but that's definitely not the "right" way. I like going to the junkyard anyway.

BTW, do you have two connectors, blue and green on yours? You seem to be saying ours are the same. I think the source of the confusion may be this diagram you posted earlier. On the right side it shows a "Vehicle Control Module" and pin 23 on Connector 4...