56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
I’m not sure we’re seeing the same picture, RD. There won’t be an additional connector in line, just another one populated to replace the existing one. The question in my mind is which approach yields the easiest way of (1) shortening the length, (2) rebundling the wires, and (3) not making a mistake. Clearly, the answer may vary by the person doing the work.
FYI, unlike your 55, the corvette ECU is mounted to the motor side firewall, on the passenger side. That’s why the run is short.
I'm trying to understand your dilemma but missing a good picture of the connector you want to redo, and where it all has to go.
The ECU has 3 connectors, you can see them in the last picture. They are molex 34566 connectors.
That's a lot of extra wire to try to stash somewhere and I agree, I'd shorten them too and I wouldn't cut and splice wires. The connector bodies aren't that expensive if you want to go that way, it's the contacts and seals that add up but in the whole scheme of things $100-150 isn't that much. It looks like the other harness with the connector with the white on it is too long as well....are you going to shorten it? It's a lot of work but it will turn out better imo.
BTW, I looked on eBay and there's a bunch of new 34566 connector bodies on sale pretty cheap ($10)....I don't know if they're the right ones. Digi-Key has them too.
https://www.ebay.com/itm/20398249498...CABEgInovD_BwE
https://www.digikey.com/en/products/...CABEgI8XvD_BwE
Why are there so many connections to the ECU? I have 3 connectors but only around 35 wires total. My system batch fires injectors 2 at a time and has a distributor, so that eliminates a bunch of wires but only 10-12. You probably have an electric throttle which adds a few, but are there that many more sensors on an LS?
56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
Maybe you could still find a way to reroute if it were possible to make a closed area between the frame rails or something. Messing with that many connections would be my last resort.
With the right Molex contacts and seals, good crimpers, and a little patience it's no big deal. It might be 3 hours of work but it's worth it imo. I would do that before I tried to cram all that extra wire someplace. Richard obviously takes pride in his work and wants to do it right.
56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
I purchased 3 new connectors (different dash numbers), pins, and a professional crimping tool. They should be here sometime this coming week. I still have to determine the new harnesses length, then it’s get it done. Lol
Not sure why there are so many more wires on an gen v LT vs LS. One item that no doubt adds quite a few wires is the direct injection with the high pressure pump embedded with the motor.
Last edited by TrifiveRichard; 01-08-2023 at 01:58 PM.
56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
The gen v LT crate motor ECU has 3 connectors, and the harness is pretty long. The ECU location chosen for the corvette (engine side, passenger side, firewall) doesn't need the length. In fact, less than half the length is needed. Rather than try and coil up 3 feet of 3 harnesses, it seemed better to just shorten everything. The ECU is pictured below, along with its harnesses.
IMG_0988.jpeg
IMG_0980.jpeg
IMG_0981.jpeg
New connectors and pins were purchased. This way, there would always be a reference for the correct location of all pins, which should help help eliminate mistakes. It turns out the factory put dummy pins in locations not used, which also helps keep things straight. In order to get a good estimate of the length needed, the firewall section where the ECU is located was mocked up. Once this was done, a connector's wires were cut a few at a time, re-routed, shortened, re-pinned, and loaded into the new connector. After the better part of 3 days and 105 wires, the 3 new connectors were re-pinned and new harnesses are finished. There's still some work to finish up, but most is done. Roughly half the wire in the factory harnesses ended up on the floor.
IMG_0985.jpeg
IMG_0991.jpeg
IMG_0990.jpeg
In case readers have a need to do the same, the following Molex part numbers were used in making the changes:
Connectors: 34566-0103 (Black), 34566-0203 (Gray), 34566-0303 (Blue)
Pins: 33467-0023
Crimp Tool: 63825-8400