95SUBURBANLM7
OBS Enthusiast
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it depends on your engine/trans/pcm/tcm combo, your harness, and your truck. for most ls swaps to INTEGRATE it into a gmt400 is no different than if you are installing it into a 55chevy chassis or a Porsche 911 conversion.... usually is 3 or 4 wire hookup no matter the chassis. the gmt400 chassis is really straight forward and a easy swap. the guy above is giving you useful good info for your gauge cluster. and yes I have installed ls swaps into a 55 chevy nomad, also in 7 porsches, 4 gmt400's, 69 Camaro, rx7, and so on... they are fun and easy swaps. do your homework as most swaps are straight forward but I have not found any 2 installs exactly the same. but most of all have fun and enjoy.
Yes the physical swapping in of the engine is easy, but SEAMLESSLY (so it looks as factory as possible) integrating the two harnesses is a different story. I can tell you now, it's not a three to four wire swap. From what I am looking at, there are fifteen wires on the old harness that need to be connected to twenty wires on the LS harness.
Here is what I am talking about.
PLEASE REMEMBER THIS IS FOR A 1995 MANUAL TRANSMISSION EQUIPPED SUBURBAN. If you have a 1995 Tahoe/Silverado, the pinouts are probably 99% similar. I dont know about an A/T equipped vehicle and quite frankly, I really dont want to.
GMT400 Blue ECU Connector "E" Side:
E6 - MIL - BRN/WHT
E12 - A/C Signal - DK GRN (By "signal", Im guessing this is letting the ECU know that the A/C is on?)
E13 - Brake Signal - PPL (Again, I assume this is to let the ECU know that the brakes are being appied?)
E15 - Ignition Feed - PNK (Power only when the ignition is on, except when cranking)
E16 - Battery Feed - ORN (Constant power, at all times)
GMT400 Blue ECU Connector "F" Side:
F6 - Fuel Pump Relay Control - DK GRN/WHT
F8 - 4WD Low Range Signal - GRY/BLK
F9 - Serial DATA - TAN
F13 - VSS - DK BLU
F15 - Ignition Feed - PNK
F16 - EVAP Canister Purge Control - DK GRN
GMT400 Red ECU Connector "B" Side:
B8 - ECT Signal - YEL - GRY
B10 - Cruise Signal - LT BLU/BLK
B12 - Fuel Pump Signal
There is the black connector, that goes to the DRAC, but I do not have and connot find the pinout guide to it. If anyone has one, please let me know ASAP.
LS Harness ECU Blue Connector:
19B - Ignition 1 Voltage - PNK (Im guessing that this is the same as "Ignition Feed" on the old harness.)
20B - Battery + Voltage - ORN (Again, Im guessing, that this is the same as "Battery Feed" on the old harness.)
33B - TCC Brake Signal Switch - PPL
35B - CPP Switch Signal - GRA (Clutch Signal Switch???)
57B - Battery Positive Voltage - ORN
58B - ECM/PCM/VCM Class 2 Serial DATA - DK GRN
75B - Off/Run/Crank Voltage - PNK
LS Harness ECU Red Connector:
9R - Fuel Pump Relay Control - DK GRN/WHT
10R - Engine Speed Signal (TACH) - WHT
15R - Charge Indicator - BRN
16R - 4WD Low Signal - GRY/BLK
17R - A/C Request DK GRN/WHT
19R - 4WD Front Axel Switch BLK/WHT
20R - VSS Low LT GRN/BLK
21R - VSS High PPL/WHT
34R - EVAP Canister Purge Solenoid Control DK GRN/WHT
43R - A/C Clutch Relay Control - DK GRN/WHT
45R - EVAP Canister Vent Valve Control - WHT
46R - MIL - BRN/WHT
50R - Vehicle Speed Output 4k DK GRN/WHT
55R - A/C Low Pressure Switch Signal - DK GRN
Im sitting here looking at my harnesses and now the list looks incomplete. Im going to post this now and then edit it with new info here within an hour.
Edit:
Ok, so of course my list was incomplete...I completely missed the C100 bulkhead connector. I believe it is the C100, please correct me if Im wrong. This is the connector that is under the brake booster. There are about thirty six, so hang in there.
A1 - Battery Fused Feed - RED - This goes to the area where the ECU/DRAC is located.
A2 - Ignition Feed - PNK
A3 - Battery Feed - ORN
A4 - Stoplamp Feed - LT BLU
A6 - A8 - Battery Feed - RED
B1 - Windshield Wiper Motor Feed - HIGH SPEED - PPL
B2 - Accessory Feed - YEL
B3 - Windshield Wiper Switch Signal - PULSE DELAY - BRN
B6 - Check Engine Indicator Lamp Output - BRN/WHT
B8 - Air Inlet Valve Motor Feed - DK GRN/WHT
C1 - Horn Relay Output - COIL - BLK
C2 - Neutral Safety Switch output - P/N - YEL
C3 - Charge - BRN
C4 - Oil Pressure Indicator Lamp Output - TAN
C5 - Coolant Temperature Indicator Lamp Output - DK GRN
C6 - Brake Warning Indicator Lamp Output
C7 - Ignition Feed - PNK
C8 - ABS Failure Indicator Output - LT GRN
D1 - ABS Diagnostic Signal - TAN/WHT
D2 - Cruise Control Engage Signal - LT BLU/BLK
D3 - Cluster Speed Signal (Tach?) - WHT
D6 - 4WD Front Wheel Lock Indicator - BLK/WHT
D7 - A/C Switch Output - LT GRN
D8 - Ignition Fused Feed - BRN
E1 - Ignition Feed - CRANK - YEL
E2 - Ignition Feed - PNK
E3 - Battery Fused Feed - RED
E5 - Ignition Fused Feed - BRN
E6 - VSS - Signal
E7 - VSS - Return
E8 - Fuel Pump Relay Feed - PRIME - RED
There is the C100 pinout...now Im wondering why I didnt just post a picture of the pinout list. Anyway, I think that all the ones that end in "Output", are going directly to the instrument panel, the ABS computer, or the windshield wiper controls.
So there are all the pins/wires that I believe are relevant to this swap. This is why I wrote that this is not merely a "3 to 4 wire swap". Now below, I am going to list which old pins go with which new pins. I'm pretty sure I am correct, but if I am wrong, please let me know.
E6+46R
E12+17R
E13+33B
E16+20B
F6+9R
F8+16R
F13+50R
F15/E15+19B/75B/
F16+34R
B8+74B
B10+???
B12+???
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