Wiring the NP236

FROM AWD'S TO 2-SPEED MANUAL SHIFT, IF IT LINKS THE REAR AXLE TO THE FRONT AXLE, POST IT HERE.
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Topic author
blinkibus
I am merely driving my van
I am merely driving my van
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Joined: Mon Oct 06, 2008 5:30 pm

Wiring the NP236

Post by blinkibus »

I have been searching around and reading all day, (needed something to do while recovering from the flu) and I did not come across useful info on the wiring part of a NP236 install, which by all accounts is the hard part. Am I missing something, or has nobody yet had the time/inclination to write it up?

I have been driving awd astro/safaris for the last 10 years or more, and now that my 2nd NP136 transfer case is going out on in my current rig despite being a costly remanufactured unit and frequent AT2 fluid changes, I need to make a quick decision whether to go for the dual-range or try to throw in a used stock case and go back to dreaming about a low range, but at least have my daily driver back. I happen to have a little extra money right now, which is not usually the case, and I have a shop and moderate wrenching skills. I am not afraid of attempting the work, but need guidance to get it done properly and in a timely fashion, like over a long weekend sort of thing.

I live in the mountains of northern California on top of a steep hill deal and my driveway is practically a jeep trail. We get a lot of snow here, and I love the AWD, but also use my van like a farm truck do a lot of back roads exploring and could actually use a low range option as there are many times when I am trying to do something with my van that it simply lacks the power/gearing to accomplish. As far as an electronically controlled x-fer case goes, I would think that everybody would want the 236. Yet few have tried it I presume due the wiring technicalities?

I understand that it is a very time consuming process to document this type of procedure, but maybe it is easier than it seems? Or maybe somebody has been sitting on the info and just needs a little motivation to post it?

Thanks to you all for this great resource.
Current Rig - 2004 Safari AWD, 270K+, Daily Driver, Dark toreador red, coated fender flares and blacked out grille and front bumper, OLV 2" lift blocks, SD Truck Springs S10 rear springs, Airbagit -30 lift keys, KYB monomax shocks, 3.73 gears, 235/75/16's on Black American Racing AR172's, Gibson Exhaust, Rear shock mounts relocated, FF Dynamics electric cooling fans, custom cold air intake with Ebay tubes and K&N cone filter.

Captn. Crunch
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Re: Wiring the NP236

Post by Captn. Crunch »

First- I'm sorry for the delay. I've been plugging along when I've had the time but I'm still not done so...sorry bout that. And you're right about the wiring being the biggest part of the job. The rest of it is strictly bolt up so no hassles there.
If your changing tc's, throw in the 236 and use your 136 encoder motor. It will work just like a stock unit and when either racrx7 or myself actually get this written up all that will be left for you is the wiring to access low range. That's where I am right now.
Also, there is very little to go wrong inside these things so save your old one, buy a new chain and friction discs and your good to go. There's a thread for rebuilding the clutch pack.
I envy you living in terrain that wears out transfer cases. Here in Ct. I have to really go looking for any kind of offroad. I'm like a kid in a candy store when it snows and I can take my van and go out and play. It's snowing now and I get out of work in an hour!
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

Topic author
blinkibus
I am merely driving my van
I am merely driving my van
Posts: 20
Joined: Mon Oct 06, 2008 5:30 pm

Re: Wiring the NP236

Post by blinkibus »

Hey Captn.

Thanks for responding so quickly. You do not need to apologize. I say, "When the berry is ripe, it will fall in to your hand."

Your suggestion is super helpful!!! That gives me the best of both worlds, a solution for right now and a sure path to low-range when we collectively can put our heads together to figure it out.

I am going to go back and study all the relevant threads again today to hopefully get the most important details to stick. If I still have questions I hope you don't mind me picking your brain and relying on your experience a bit more.

Cheers.
Current Rig - 2004 Safari AWD, 270K+, Daily Driver, Dark toreador red, coated fender flares and blacked out grille and front bumper, OLV 2" lift blocks, SD Truck Springs S10 rear springs, Airbagit -30 lift keys, KYB monomax shocks, 3.73 gears, 235/75/16's on Black American Racing AR172's, Gibson Exhaust, Rear shock mounts relocated, FF Dynamics electric cooling fans, custom cold air intake with Ebay tubes and K&N cone filter.

racrx7
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Re: Wiring the NP236

Post by racrx7 »

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Use this switch from a 2000 and earlier Suburban/Tahoe, if you can. Any of the 4 button switches will work, but they will be difficult to mount due to their odd shapes. Dormant makes a replacement switch pictured, http://www.amazon.com/dp/B00A14O8LC/ref ... GTYT4EP6US , that is supposed to be better than the OEM one. You will have to do some re pinning of the wires to it, but you will be re pinning the TCCM also.

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The top connector is our factory connector. The lower one is from the 236 donor vehicle. It uses the came wires as the 136, but obviously adds more wires from the encoder, switch and front axle dissconnect circuits. You will transfer these extra wires to your existing 136 connector. You'll notice two black ground wires in the 136 connector, (upper far left pins), and only one used in the 236 connector. I removed the second from the left and taped it up. It's not used in the 236 setup and I have no way to verify if it will or won't damage the TCCM if left in the circuit. It works perfect with the one ground wire.
O3 Astro 4X4
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Dropped front IFS axle
Journeys rear spring hangers and shackles, S-10 leaf springs, 2" body lift
255/70-16 BFG KO2's on 16x8 Fuel Revolvers
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