building a C3(747) to P4(730) adapter harness

[34blazer]

Gents,

Per the title, just had a question before I mess something up. Took apart an old 165 that Ive had for 10years, salvaged the female connector. Had to cut the pins from the board. Looking for someone who has built one, mainly I need to know what was used(if any) to connect the wires to the pins in the female connector. Also, I may need new pins since the old ones are now shorter, where can I grab some new ones? Thanks!

[1project2many]

I've used non-insulated crimp connectors but they take up too much space. Most of the time I wrap the wires around the terminals then solder them in place. I put adhesive lined shrink tubing on the wire before soldering so I just slide it down afterward and heat it up. After the adapter is made and connected to the harness connectors I'll try to use a zip tie to reduce strain on the adapter wires if possible. I can't tell you where to get the pins though. I use shop air to blow all the solder away after I heat it so I don't have to cut the pins.

[Six_Shooter]

In this thread (http://www.gearhead-efi.com/Fuel-Injection/showthread.php?944-Finally-getting-another-Delco-project-done-or-started....) it shows how I've connected wires to the ECM pins.

I've also done it with just soldering the wires to the pins, which I did for a '7747 to '7730 harness adapter, but didn't seem like a great way of doing it. I found the above solution on some site somewhere and used it with great success.

[34blazer]

In this thread (http://www.gearhead-efi.com/Fuel-Injection/showthread.php?944-Finally-getting-another-Delco-project-done-or-started....) it shows how I've connected wires to the ECM pins.

I've also done it with just soldering the wires to the pins, which I did for a '7747 to '7730 harness adapter, but didn't seem like a great way of doing it. I found the above solution on some site somewhere and used it with great success.

thats what i was looking for, if you remember where you found those connectors let me know. thanks!

[Six_Shooter]

Local electronics specialty store.

[34blazer]

are those simple butt connectors, i may have to look online. most places around here sell phones and speakers lol

[JeepsAndGuns]

I didnt have any luck finding any terminals localy that would fit and clear each other. I just ended up sodering the wires directly to the pins when I made mine.

[PJG1173]

Local electronics specialty store.

LOL is there such a thing anymore?


are those simple butt connectors, i may have to look online. most places around here sell phones and speakers lol

I have found them at the shack but they are usually in a kit to assemble some sort of plug. definitely not worth buying 20 kits for the butt connectors. I've went the solder and shrink tube route on similar projects. It works pretty good, just be careful not to over heat the pin and melt the housing. another alternative is to use a project board and solder to that, but that goes back to the local electronic supply problem.

[Six_Shooter]

LOL is there such a thing anymore?

Around here, yeah, there's one place in town, that carries some stuff, like the connectors I used for the adapter harness, but very limited selection. There's a plac in a city about 15 minutes away that has an AWESOME selection of electronics, parts, and tools. Then if I drive another 45 minutes to an hour and a half beyond there, there are places with even better selection.

[34blazer]

Ok Gents,

found a relatively easy solution to connect the wires to the pins. i had some 18-22 awg butt connectors laying around, took the plastic sheath off and was able to crimp one end to the pin. connected the other end to the wire and then flattened the whole thing in the vise. tested it out in the connector and have plenty of clearance. going to flux/solder/shrink wrap each one for the warm fuzzies. pics when finished....

i have a home for almost all wires/circuits, except the injector grounds. according to the wiring diagrams ive referenced it looks like ill need to connect pin D6(730) to A12(730 system ground) and D7(730) to D1(730 system ground). looks like these are all tied together? do i need to bridge the grounds together, or can i keep them separate, or ground them to A12 or D7?

thanks!

[EagleMark]

I get bags of 100 of the connectors without plastic cover and use them to solder wires together without crimp. If you have the correct crimper for them it works great with shrink wrap too... Plastic butt connectors are temp fix only for me... just an issue waitng to happen.

[34blazer]

pretty much, only reason i flatten them is for tight quarters on the ecm connector, they are aluminum and im going to solder and shrink wrap them for added warm fuzzies. any info on the injector grounds? AFAIK the 7747 harness doesnt show them on the pinout

[EagleMark]

Actually the wires going to ECM from injectors are grounds, the other end of injector goes to power.

[34blazer]

yeah i figured, ill tie them into the existing system grounds per the 7730 $A1 pinout. thanks!

[EagleMark]

I reworded my post above, the wires going to 7747 ECM from injectors are grounds, the other wire to injector is from power, not from ECM.

[1project2many]

I did the same thing but the wall thickness of the connector is too large. What you really want is splice connectors. These are also the correct conenctor when connecting several circuits at one point, like your injector power and ignition power wires.
http://www.digikey.com/product-search/en/connectors-interconnects/terminals-wire-splices/1441974

[34blazer]

the rear or the top row pins(A & C rows) have been bent out so the are directly aft of the connector. the bottom row is slightly bent aft(approx 45*), test fit the pins w/connectors and has plenty of clearance. back to work this week so i doubt it will be finished soon. hopefully will be done by friday with fini pics.

[1project2many]

Well, it sounds like you've got it figured out, then. If those sleeves are really aluminum like you said you might want to test solder one before crimping all of them.

[34blazer]

yeah, i just finished the E/F connector, solid and a little bit more snug but thats because of the shrink wrap. but overall i think it will work well once all the pins are home

[EagleMark]

In case someone missed this on Thirdgen it is an easier version to solder up some wires to. Way less work then removing one from an ECM as well.

http://www.racetronix.biz/itemdesc.asp?ic=RHCA-001&eq=&Tp=

[JeepsAndGuns]

In case someone missed this on Thirdgen it is an easier version to solder up some wires to. Way less work then removing one from an ECM as well.

http://www.racetronix.biz/itemdesc.asp?ic=RHCA-001&eq=&Tp=

Wow, thats sweet! Wonder if they make one for the 7427 style pcm's?

[34blazer]

almost done, just need to tidy it up a little more...

[1project2many]

So as I was sitting in the barn separating lots of cut wires from ecm connectors tonight, I realized that missing the painfully obvious is a good way to win a Darwin Award. IOW, the terminals designed to fit the ecm connector could be trimmed, slipped over the pin and soldered, then shrink wrapped, and they'd do a very nice job.