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408cuda · 02-01-2009, 03:13 PM

Ok guys, did some more ciphering on the harness yesterday. I think I got most of it traced out. This is what my 3rd (white connector that leads to gauges and ALDL) near the ECM looks like, and how I interpret it.

A-A9 wht/blk=ALDL diag enable
B-A5 brwn/wht=SES light ground
C-empty
D-A7 tan/blk=TCC/shift indicator
E- To RH injector, red=12v keyed power?
F-A6 pnk/blk= 12v ign " "
G-empty
H- To air diverter connector, brown
J-C9 prpl/wht= crank input needed for anything?
K-B10 orng/blk=Park/neutral... this is empty on ours, had no wires coming out
L-RH o2 sensor, prpl. Not hooked up
M-A10=VSS, brown. Did this go to the buffer under the dash? I thought the other two controlled VSS?
N-Ground, blk/wht
P-Fuel pump relay, red/wht
R-A8=ALDL data

Also have a light blue/blk wire in the ALDL connector that I snipped out of the donor harness under the dash, couldn't see where that went. Guessing I can lose that.

And in this shot you can see the red mystery wire that comes in with the ECM connectors. One side goes to the power strip/block with a fuseable link.

Wires I have left on the bulkhead/fuse block side.
Blue-green NSS wires, or at least that's what I thought they were. Maybe they go to the gauges?
Purple/wht-yellow VSS wires, into cab through VSS buffer?
Tan, unknown. Looks like it was long enough to reach the fuel pump relay, or maybe IAC? Anyway I looked at all the sensors and I just don't see anything missing. Distrib has all of it's wires too.
Pink, coil hot, 12v start/run
Dk Green, temp sender goes to front of L cyl head, for factory gauge I presume? I was thinking of putting in an aftermarket gauge here.
Purple, starter engage wire 12v
Red, goes to power block. I was thinking of using this for 12v power to the ign key?

I ended up finding a service manual in my shop on the book shelf (d'oh) and it helped some, but I still didn't see anything useful for under the dash. Under the wiring for the air diverter it says "if equipped" does that mean I can ditch it? It wasn't hooked on our donor and the truck ran pretty good.I see those valves cost a few bucks.

Also, I don't recall any from of speedo cable provision on this trans, can I still use an aftermarket VSS converter?

Thanks for all the help, I know you guys must get sick of the same questions but I'm not very familiar with these trucks or systems, and wiring isn't my forte' either.

Sorry to hijack your post cj! How are you making out on yours?

02-01-2009, 03:13 PM	#61
408cuda Registered User Join Date: Jan 2009 Location: White Creek NY Posts: 14	Re: Tbi swap build thread Ok guys, did some more ciphering on the harness yesterday. I think I got most of it traced out. This is what my 3rd (white connector that leads to gauges and ALDL) near the ECM looks like, and how I interpret it. A-A9 wht/blk=ALDL diag enable B-A5 brwn/wht=SES light ground C-empty D-A7 tan/blk=TCC/shift indicator E- To RH injector, red=12v keyed power? F-A6 pnk/blk= 12v ign " " G-empty H- To air diverter connector, brown J-C9 prpl/wht= crank input needed for anything? K-B10 orng/blk=Park/neutral... this is empty on ours, had no wires coming out L-RH o2 sensor, prpl. Not hooked up M-A10=VSS, brown. Did this go to the buffer under the dash? I thought the other two controlled VSS? N-Ground, blk/wht P-Fuel pump relay, red/wht R-A8=ALDL data Also have a light blue/blk wire in the ALDL connector that I snipped out of the donor harness under the dash, couldn't see where that went. Guessing I can lose that. And in this shot you can see the red mystery wire that comes in with the ECM connectors. One side goes to the power strip/block with a fuseable link. Wires I have left on the bulkhead/fuse block side. Blue-green NSS wires, or at least that's what I thought they were. Maybe they go to the gauges? Purple/wht-yellow VSS wires, into cab through VSS buffer? Tan, unknown. Looks like it was long enough to reach the fuel pump relay, or maybe IAC? Anyway I looked at all the sensors and I just don't see anything missing. Distrib has all of it's wires too. Pink, coil hot, 12v start/run Dk Green, temp sender goes to front of L cyl head, for factory gauge I presume? I was thinking of putting in an aftermarket gauge here. Purple, starter engage wire 12v Red, goes to power block. I was thinking of using this for 12v power to the ign key? I ended up finding a service manual in my shop on the book shelf (d'oh) and it helped some, but I still didn't see anything useful for under the dash. Under the wiring for the air diverter it says "if equipped" does that mean I can ditch it? It wasn't hooked on our donor and the truck ran pretty good.I see those valves cost a few bucks. Also, I don't recall any from of speedo cable provision on this trans, can I still use an aftermarket VSS converter? Thanks for all the help, I know you guys must get sick of the same questions but I'm not very familiar with these trucks or systems, and wiring isn't my forte' either. Sorry to hijack your post cj! How are you making out on yours? Last edited by augie; 04-20-2011 at 12:10 AM.