Why 2 or 3 wires to starter? (5.0 Conversion)

[ttbit]

OK...this really should be simple....but... I am working on my 5.0 conversion on the 2001 ST and the 2001 starter harness has 2 large wires going to the starter, and maybe a 3rd smaller one. Doesn't the '96 starter only need one from the starter relay? It appears that the 2001 has a relay in the fuse box, where the '96 had one on the inner fender.

Do I need to install a fender relay also? Maybe the fuse box relay won't handle the current draw? On my 2001 wiring diagram, it appears that one wire goes right from the battery to the starter and then the second to the relay.

Maybe I am making too much out of this, but would like to use an existing harness, if I can, but of course, the wires are too short anyway as the starter is on the opposite side on a 5.0. If not, I will buy a new battery cable and wire it like a '96.

Two things I did not grab from my donor vehicle...starter wiring and alternator wiring... Either I didn't grab them, or I lost them in one of my two home moves this year.

Thanks,
Don

 

[chad551]

Cannot help you out, but would like info on your finished project..

 

[slyfoxexplore]

its all kinda up to you on what you want done i would run a higher power relay becuase some reason on my 96 its needed and always seems like on those cold days the starter needs more juice from battery

 

[ttbit]

OK...I got it.

Thanks. Well, I looked at the wiring a little closer. I didn't notice the 3rd connection on the starter as it is not a stud, but a tab. I will extend the 12 ga and 4 ga wires to the starter from the factory 2001 harness and see how that goes. Found the 3rd wire (4 ga) to be a ground, so I will ground that to the block.

I have been taking pictures of the build and plan to post a web site when done.

I still have not seen anyone else do a 5.0 Sport Trac.

What was confusing was that I didn't realize that the 2nd positive wire in the schematic was the 12 ga wire. All makes sense now. I was wondering why 2 positive 4 ga wires would be going to the starter! Of course, if I have problems, I will use a old style starter relay.

 

[CDW6212R]

Try to find Eric's 302 conversion, he used a 2000 model V8 donor I believe for his 99 Sport. He should have had a good match between the harnesses, which may be the same as yours. Does the Sport Trac have a long Power Distribution Box, or a somewhat shorter/rectangular box? If you use all of the donor engine harnesses, then the conversion should be mostly at the PDB, and the firewall connectors. I don't know the details, but I have seen most of the various harnesses. Regards,

 

[ttbit]

Hey Don,

It is more of a rectangular box and not too long. I have the shop manuals on CD for both, but am still getting used to navigating without a big shop book. It doesn't look like there are too many wires I need to change over though. Just the 42 pin connector, the starter and the alternator wiring differences so far.

Haven't thought much on the speedo yet. The PCM will get what it needs, but will probably need to do something about the speedometer itself.

 

[CDW6212R]

You will be working on the wiring from the PDB to the rest of the bay, keep your original PDB. I don't know much about the Sport Tracs, but other than say the GEM it should have very similar wiring circuits. They will have a lot of changes like the PDB and various connectors of course.