Connector considerations

[GrowlingandBiffo]

Have just collected some Bosch 55pin ECU cases. Puegeot Citreon BMW ect £10 each

[Fred]

If space is getting tight, do remember to ditch the extra 8 adc conditioners and your 8 LEDs and maybe other stuff i can't remember right now.

[jharvey]

Right now I'm working on the most critical, and largest parts first. The drivers and RPM circuit are big ones, then it's temp, bat V, ect. Then if space allows it's extra AN protectects, LED's ect. I could stand resistors ect up on end if I really need space, however I'm laying them flat to help spread it out some. Thanks for the reminder. I'm sure we can get it to fit.

[WTDeuce]

Ive despised the dsubs since I first had to deal with them on my MS. I hate them with a passion, mostly due to crap current capacity and a nightmare to work with. Plus, its hell to try to drill holes for them. So I found other solutions, albiet slightly more expensive....

I like the AMP CPC (Circular Plastic Connectors) line. Theyre cheap, they use crimp pins/sockets, theres quite a few sizes, good current capacity, and wont come loose. Theres a strong click ones the two shells are twisted together. The pins and sockets are separate parts, so if someone has a 50 position connector but only needs 25 connections to start, thats all they have to buy. Im using two of them on my MS case, a large 60 position one ($4 or 5 for each side) and a 9 pin one. The 60 pin does all low current stuff, sensor and injectors. 9 pin does ignition and grounding. I could have used shells with fewer positions but the price difference was minimal. These are easily available from Mouser, Digikey and eSonic. And lots of other places im sure. The pins and sockets can be removed without a tool by snapping the shells apart (theyre designed to do this, but its a pain to put them back together if you have more than a few positions filled), but the removal tools are cheap. I could have passed on the 9 pin and used two pins on the 60 pin shell per coilpack, but oh well. My coilpacks draw 13 amps or so each.

The only downsides are that the pins and sockets are milspec style, so a milspec crimper is needed (small crimper for the low current pins, large crimper for the big pins). I bought my small DMC crimper on ebay for $50 I think, and if youre careful they can be crimped without a turret or head ($40 or so, and a turret AND a head are needed). I dont know if there is a version that can be soldered to a board directly, I have wires running from the connector to my board. And lastly, I havent looked into alumel/chromel pins and sockets for EGT sensors. I also dont know about weather sealing, that wasnt an issue for me because case is mounted inside the car.

In hindsight these CPC connectors would have been sufficient for my firewall connectors too, probably.... But I went a different path as seen below.





I also like Deutsch Autosport connectors, however these are probably beyond most peoples budget... Theyre milspec connectors that are used in racing. Huge range of sizes and styles. Fully weatherproof, etc. Also need a milspec crimper. I use these on my firewall because im crazy. Biggest downside is again EGT pins and sockets... I priced it out, and it was going to be $80 per EGT sensor (two pins, two sockets, $20-22 EACH).

Again I used two of these, a 64 pin and a 9 pin. The 9 pin handles my fuel pump, coilpacks, grounding to engine, and down the road a water injection pump. 64 pin handles everything else. The 64 pin shells ran me $80-100 each, pins are around 70 cents each I think but I might be wrong there.

The cheesy aluminum plate is to mount them to my firewall. Doesnt do anything much justice, but oh well it works for now. Should be reasonably weatherproof too. Ill do something better down the road when I can make sure this will be permanent.





Edit: One more pic showing the harness end of the Autosport connector. And my engine wiring harness....

[jharvey]

Nice, I hope you have a sticker that says "apple in side"

I'm glad to here good review of the CPC connectors, I've looked at them in a Digikey catalog, but don't have any experience with them. I seem to recall they had a solder version as well as a crimp version. Have you tried the solder version? I'm curious about the difference in price. I'm also curious if the crimp versions could be made into soldered connections if you felt so inclined.

Do you recall if you had to buy your pins separately? I know many DB connectors come with the pins, I don't know if the pins I saw listed in Digikey were spares, or if the where required.

[jharvey]

A quick note about the connector card. We could have OEM connector(s) at one end of the PCB, and a test connector at the other end. Perhaps one that fits the Jim Stim, as the test connector, then the other end might have a Miata (or insert car brand) connector. Just another thought.

[WTDeuce]

Its just an old Apple IIe power supply that I use for testing my MS and stuff :p

I can have a look and see about the solder version. I doubt you can turn the crimp into solder ones, as the crimp connectors are usually gold plated (at least all the ones ive ordered so far have been). It would also be REALLY hard to solder the pins and sockets for 20-24AWG wires. Ill order some of the solder pins and see what theyre like.

Yup I had to buy the shells, pins and sockets separately but theyre all available from Digikey/Mouser/etc.

[Fred]

We could have OEM connector(s) at one end of the PCB, and a test connector at the other end. Perhaps one that fits the Jim Stim, as the test connector

Good idea! :-)

[davebmw]

We could have OEM connector(s) at one end of the PCB, and a test connector at the other end. Perhaps one that fits the Jim Stim, as the test connector

I would like to second that, its a very good idea to have that kind of flexibility even if the connector is not a DB37. Access to the relevant lines to simulate all the I/O channels would be really handy especially for firmware upgrades and such.

[Fred]

Perhaps using an OEM connector for the FreeEMS is a good idea, cheap and easily had? Another thread, anyway.

Yeah, this thread :-)

You can order those brand new too. The trick would be standardising on one and choosing which one it should be. The OEM ones from japan at least aren't waterproof either. I personally don't mind Jared's inline idea provided the wires come cleanly off the board.

Fred.