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TennesseeZ · 02-16-2012, 08:40 AM

Thanks!
I've been researching this for the last couple hours, and here's what I think I've learned;

GM has issued a service bulletin addressing installing the newer model actuator (electric motor driven) to replace the older (thermal actuated) one. They have also made available a wiring harness for the installation. The wiring harness kit seems to include a spacer for the actuator.

Here's a couple links to the info: http://www.fullsizechevy.com/forum/g...tor-years.html

http://www.justanswer.com/chevy/2vrb...tuator-88.html

The second one seems to have a copy of the TSB, but it's not real clear to me. The first lists the part numbers more clearly.

There are different part numbers depending on what year and model truck is being upgraded.

The harness for my truck (1992 K 2500, 6 lug) is available from Dorman through local parts stores. The number is Dorman 600-600, it varies in price from just under $50 to around $55, (plus 9.75% tax here), which puts it around $55-$60, and seems it must be ordered. Rock has it for just under $40 including shipping.

The harness seems to have several feet of wiring, some of which is insulated from heat.
This leads me to beleive the splice will probably be somewhere near the transfer case/floor mounted actuator lever area, and will be routed near the exhaust system. The spacer does not seem to be included, unless it's the small circular black thing that looks like a plug.

The TSB gives different locations to splice the new harness into the existing one, depending on application.

I have not yet located the connectors mentioned for my installation, (For 1993 and prior vehicles, splice into CKT 50 (BRN) between connector C152 and GT101). I'm not sure if I have a schematic that would show these connectors, as I have misplaced the wiring supplement supplied with my Helms manual, and have not yet found it in the Chiltons. But I'm pretty sure I can find a brown wire in the transfer case area

. Just don't know whether to splice before or after the transfer case switch.

I think I'm going to order the harness from Rock, as I have something else to drive, and can also drive the K2500 without 4X4 if necessary.

It is also possible to install the newer actuator using a dash mounted toggle switch, there is an aftermarket cable operated kit available, and a kit to permantly lock the axle (all available from Rock), but I plan to use the later model actuator and Dorman harness.

If I've missed anything, or you can identify the connectors, please help me out.

02-16-2012, 08:40 AM	#3
TennesseeZ Countdown Survivor Join Date: Aug 2007 Location: Bean Station, East Tennessee Posts: 9,676	Re: Front axle actuator questions (pics) Thanks! I've been researching this for the last couple hours, and here's what I think I've learned; GM has issued a service bulletin addressing installing the newer model actuator (electric motor driven) to replace the older (thermal actuated) one. They have also made available a wiring harness for the installation. The wiring harness kit seems to include a spacer for the actuator. Here's a couple links to the info: http://www.fullsizechevy.com/forum/g...tor-years.html http://www.justanswer.com/chevy/2vrb...tuator-88.html The second one seems to have a copy of the TSB, but it's not real clear to me. The first lists the part numbers more clearly. There are different part numbers depending on what year and model truck is being upgraded. The harness for my truck (1992 K 2500, 6 lug) is available from Dorman through local parts stores. The number is Dorman 600-600, it varies in price from just under $50 to around $55, (plus 9.75% tax here), which puts it around $55-$60, and seems it must be ordered. Rock has it for just under $40 including shipping. The harness seems to have several feet of wiring, some of which is insulated from heat. This leads me to beleive the splice will probably be somewhere near the transfer case/floor mounted actuator lever area, and will be routed near the exhaust system. The spacer does not seem to be included, unless it's the small circular black thing that looks like a plug. The TSB gives different locations to splice the new harness into the existing one, depending on application. I have not yet located the connectors mentioned for my installation, (For 1993 and prior vehicles, splice into CKT 50 (BRN) between connector C152 and GT101). I'm not sure if I have a schematic that would show these connectors, as I have misplaced the wiring supplement supplied with my Helms manual, and have not yet found it in the Chiltons. But I'm pretty sure I can find a brown wire in the transfer case area. Just don't know whether to splice before or after the transfer case switch. I think I'm going to order the harness from Rock, as I have something else to drive, and can also drive the K2500 without 4X4 if necessary. It is also possible to install the newer actuator using a dash mounted toggle switch, there is an aftermarket cable operated kit available, and a kit to permantly lock the axle (all available from Rock), but I plan to use the later model actuator and Dorman harness. If I've missed anything, or you can identify the connectors, please help me out. __________________ 93 Yukon 89 Silverado Z71 SWB Sport 91 K 2500 Silverado "Lobuk-Worktruk" A MAN OF HONOR DOES NOT LIE, CHEAT, OR STEAL, NOR TOLERATE THOSE WHO DO. Gettin' old ain't for sissies. Last edited by TennesseeZ; 02-16-2012 at 09:25 AM.