My 88 vert was broken into while in outside storage prior to my buying it. While going through it last night to see what needs to be done to get it rolling under its own power again I found that someone had hacked off one of the ECU connectors from the harness. My question is, if I can get the connector with pigtail from another car can it just be spliced in or would I need the whole harness? If it can be spliced, can it just be butt spliced or does it need to be soldered in? I can do it either way but there isn't a lot of space to work in down there. Thanks in advance for any help!

 

You can splice. You would either solder it or you could crimp connect it, but the crimper would need to be a quality tool.

 

Solder, it takes longer but when you won't have to worry about it getting loose.

 

Thanks for the input! The more I thought about it I would much rather go to the trouble of doing it proper with solder than not anyway. I was able to find a localish guy that has the pigtail so I will be picking it up this weekend.

 

Before you get the idea that soldering is better than crimping or vise versa, let me just reiterate what our resident Rotary Anything genius Aaron Cake said while building a harness for his 1976 Cosmo.

As long as it is supported correctly, either works just peachy. I personally prefer to crimp as I'm not too good with a soldering iron yet on the bench, much less in cramped quarters of the passenger footwell. Plus, there's less risk of setting something on fire

The exact method I use is to take the insulated splices you can find at any hardware store, dremel off the red/blue/yellow vinyl insulation with a diamond cutting disc, crimp them using a normal crimp tool and then slip the heatshrink over it (1/8" is the right size for these wires). It's slightly bigger than a soldered joint, but can be done much easier. Good if you want to feed ECU signals up to gauges or stuff like Coolant Temperature, Boost Pressure, O2 and so on.

Even a basic crimp tool from Harbor Freight will make a solid crimp. Just be sure to use double wall adhesive lined heat shrink on each connection. I use two crimp tools, one for generic insulated terminals and one with a tooth for non-insulated ones. Just make sure you match up each wire to the pinout in the Factory Service Manual here first: Foxed.ca. Nothing sucks more than trying to trace wires that change colors halfway through a repaired harness.

 

That is all very good info. I work at a local Mercedes dealer and we have in stock some heat shrink/solder built in connectors that Mercedes wants used anytime a harness is repaired. I may end up going that route. They are a bit more expensive but it may be worth it in the long run. What do you think?