Now, I just got this car friday. Basically its an 87' s4 N/A with like 278000 kms on it but the motor was swapped out for a lower milage one...I have no idea. Now, the people who did this were the absolute dumbest mother ******* ever and didn't connect a shitload of wires. There is a 6 hole white connector on each side, a 3 hole green one on each side I was wondering what those do and theres the 6 green which is the diagnostic port. Now, theres also a plate that looks like it bolts to the motor on the right side...I think it might be a ground plate or something..am I right? And will this prevent the car from starting? P.S this car was running with its old motor and the donor car's motor ran strong before it was swapped in so basically I'm 100% sure its a wiring issue because these guys were clearly retarded and left so much stuff disconnected.. Basically my question is what is that plate thing, and what do the white 6 holes and 3 green hole connectors do?



P.S This car has almost no underbody rust except for the control arms and rotors n stuff...only 3 or 4 spots on the hood and 1 on the fender and I got it for 1500 on a trade (deal hasn't finished yet guy is giving me the chance to get the car running first) I'll take pictures tomorrow.

 

Before you diagnose any wiring problems, do yourself a favour and install new grounds.



Motor to chassis

Battery (-) to chassis



Clean up your ECU mounting on the passenger side floor under the carpet (the ECU grounds off in the body of the ECU to the chassis)



Clean up the coilpack mounting flanges. Scrape off paint or grease or oil, then bolt them back down. The coilpacks ground out by the mounting flanges, which obviously, bolt to the chassis.



Some types of sensors existing on the block ground out directly to the block, which is why you should have a good chassis ground.



After this is out of the way, then you can begin to diagnose any problems (if this didn't solve them already, which chances are, it will).





It's like a 20 year old car now, the grounds are probably shitty.

 

Alrighty, awesome...I'll do that as soon as it stops raining.

 

Almost all of the electrical connectors are unique. Find a matching plug somewhere in the vicinity, and just plug it in.



Otherwise, post some pics so we know what the heck you're talking about.