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finished my underhood wiring harness

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Old Sep 8, 2003 | 11:47 PM
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Gen3Benz's Avatar
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Default finished my underhood wiring harness

i made an ls1 twin fuse box harness into a single fuse box by removing un-needed fuses and relays. i kept connectors 100, 101, and 105 to hook up to the engine/trans harness. i hacked a 3 prong terminal to run 6 ign and 3 b+ mini fuses. i will run an external ign relay off the red wire(maxi fuse out) to the pink wire(ign feed). grey wire is for fuel pump. all the needed relays fit nicely into one fuse pack, using factory fan relays. only took a few hours and cost me 2 dollars for zip ties.

fuses removed
lh hdlp, rh hdlp, horn, abs bat, tcs bat,strtr, abs ign, a/p
ip 1+2, abs bat 1+2, h/l dr horn

relays removed
fog lamp, horn, starter, air sol, air pump
Attached Thumbnails finished my underhood wiring harness-fuse-panel.jpg   finished my underhood wiring harness-wiring-harness.jpg  

Last edited by Gen3Benz; Dec 27, 2004 at 11:17 PM.
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Old Sep 9, 2003 | 01:31 PM
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Default Re: finished my underhood wiring harness

That's nice! I declined the donor car's underhood fuse panel, thinking I'd make that and the relays look and function more like the receipient car (1982 Camaro Z28) electrical system.

The data below is my latest summary on the project progress.

PCM wiring needing connectivity with the car's chassis harnesses:

CKT_NO DESCRIPTION
340 Battery 12VDC to PCM
48 Clutch PP Switch
335 Fan 1 Relay Control
340 Battery 12VDC to PCM (tied to above ckt 340)
451 PCM ground
439 Ignition-switched 12VDC to PCM

465 Fuel Pump Relay Control
121 Tach Output
473 Fan 2 Relay Control
428 Evap Cannister Purge Solenoid (can wait)
1310 Evap Cannister Vent Control (can wait)
817 VSS Output to Speedometer
419 Malfunction Indicator Lamp

Independent of the PCM, I need to bring ignition-switched 12VDC from the interior fuse panel for the injector harnesses (INJ 1, INJ 2 fuses), as well as ignition-switched 12VDC for the {fan 1, fan 2, fuel pump} relay pulls. No under-hood fuse panel on 3rd gens, they're all under-dash.

I'll need to fabricate a 12VDC fused feed from batt positive to the fan relays to feed the fan motor relays, and another 12VDC feed to the fuel pump relay.

Electrically, this looks like it for now. I'll need to come back to the ALDL/OBD-2 connector, and the gauge {oil pressure, coolant temp} feeds instead of using the Class-2 Serial Bus which outputs in unuseable form for my gauges. Plenty of unused wires in the thru-fender LS1 harness I can repurpose for those, and land them right in place to connect to the 3rd gen chassis C207 connector in the pax
footwell. The remainder of the wires hit the 3rd gen chassis C100 connector on the driver side firewall.
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Old Sep 10, 2003 | 06:25 PM
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Default Re: finished my underhood wiring harness

very nice

I really like the wiring and such that goes into a conversion, not many people have the paitence and willingness to do a nice job like that, without hacking it up.

Yours looks very profesional

Ryan.
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Old Jul 10, 2005 | 12:13 AM
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Default

if you removed the starter relay, how are you controlling the starter? or is it setup "closed loop" just with the key(PCM doesnt see the start)
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Old Jul 10, 2005 | 09:09 AM
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Default

Originally Posted by JordonMusser
if you removed the starter relay, how are you controlling the starter? or is it setup "closed loop" just with the key(PCM doesnt see the start)
The starter solenoid is activated directly by the ignition key switch on mine, same as it was in the original '82 and later '88 harnesses.

The wire gauge on the LS1 harness feeding the solenoid was same size as the wire coming off my '82 circuit, so the current handling capacity was already there...no point complicating things w/ a relay in that case.
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