First time wiring an engine. Please help!!!
 

Ok guys I have an '81 Chevy shortbed with
c.i. SB400.
No A.C.
One wire alternator
High torque starter.

I purchased a stock replacement engine harness for my truck. I got the harness plugged into the fuse box through the fire wall and the bolt in. I plugged the next two plugs into the windshield wiped motor. Now where in the heck do the rest of the wires go? Haha!

1. One really Long thin pink wire with a round rubber cover.
2. One heavy red wire about one foot long.
3. Two red wires spliced into one single black wire

Further down....
4. One long thin green wire with a white plastic connector.
5. Three thin wires (pink, light blue, dark blue,) leading to a big black plastic plug with a side snap.
6. Fat pink wire with white plastic connector.
7. Thin light brown wire with a round rubber connector.

Further down...
8. A light blue wire with a plastic grey connector.
9. Two wires (one brown, one red) with a white plastic connector.
10. One red wire with a rubber boot.

Further down...
11. One purple wire
12. Two red wires spliced into a black wire.
13. One red wire spliced into a brown wire.
* the black and brown wire then splice together at a connector.

Please help me not burn down everything! The battery is disconnected for now! Thanks!
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Re: First time wiring an engine. Please help!!!
 

Post up some pics of the plugs you are having trouble with. A lot of time the connector shape is a giveaway.

Re: First time wiring an engine. Please help!!!
 

You must get a wiring diagram!!!!!!!!!!!!!!

Re: First time wiring an engine. Please help!!!
 

All the wiring diagrams I have found make my head do this :bomb:
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Re: First time wiring an engine. Please help!!!
 

You are in trouble. The best thing for you to do now is try to find another similar truck and see where the wires go on it. If you can't do that, post again and I will get a diagram and do what I can to help.

Re: First time wiring an engine. Please help!!!
 

I know tha feeling

Re: First time wiring an engine. Please help!!!
 

Let me toss in some general information here for those thinking about rewiring. I've rewired a pickup and 2 cars over the last several years without buying a prebuilt harness. You will need a good wire cutter/stripper, several rolls of wire in as many colors as you can find, for newer trucks mostly 16 and 18 gauge. Terminals will come later. Step one: open all harnesses so you have access to each individual wire. If there are unused wires in the harness, check both ends to be sure then throw them out. If not certain leave them in for now. Make a list of connector types used on your truck and the gauge of those wires. The cutter can be used to determine wire gauge. Pick a wire, be sure you know which end is connected to what, make a new wire to match with the correct terminals, put that wire in and toss out the old one. Repeat as necessary. It ain't that hard, guys, and will save you a boatload of money.

Re: First time wiring an engine. Please help!!!
 

Thanks for the info but I have already purchased a stock replacement harness.

I'm trying to determine where the wires go on a stock replacement setup. My other harness had already been hacked up by someone with a set of wire cutters and electrical tape. I know how to use wire cutters and connectors I just need help with where the wires need to go. That is the hard part.

If anyone can give me a step by step or a good wiring schematic I would greatly appreciate it.

Thanks!

Re: First time wiring an engine. Please help!!!
 

I BELIEVE that 9 and 10 are for the alternator for a 3 wire setup

Re: First time wiring an engine. Please help!!!
 

Re: First time wiring an engine. Please help!!!
 

Sorry for triple posting but my guess is that 5 is for distributor..but the diagram only shows 1 wire, a pink wire, going to distributor B+ terminal, 8 perhaps choke, and purple wire perhaps Starter? Just judging from the diagram (same diagram as the Haynes repair manual)

Re: First time wiring an engine. Please help!!!
 

See I'm really having trouble trying to convert that whole part. I need to get rid of the fuse block all together I think.

All I need is to run one wire from my alternator to the starter where the battery hooks to it. My problem is figuring out what wires to elminate from the factory harness.

I am also running and HEI so I need to figure that out too.

Re: First time wiring an engine. Please help!!!
 

I'd plug 10 to the batt terminal on the alternator and leave 9 disconnected. Then once the engine is wired enough to fire, just check the voltage at the battery (assuming truck is at a high enough rpm). 5 should just plug right into the distributor cap

Re: First time wiring an engine. Please help!!!
 

i dont know if this will help but it is for vary basic chevy engine harness

Re: First time wiring an engine. Please help!!!
 

This might help.
http://forum.73-87chevytrucks.com/sm...?topic=11766.0

Re: First time wiring an engine. Please help!!!
 

Did you ever find a good diagram? I'm trying to wire up my 350 in my 81 that I converted to a serpentine setup, and I have no idea what wired go where. I am using the factory harness.
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Re: First time wiring an engine. Please help!!!
 

Grab the 1980 GM Wiring diagrams (foldout pages) and the 1981 GM service manual (the 1981 wiring diagrams are in the back on 8.5x11 pages but are harder for me to follow than the big foldouts)
http://67-72chevytrucks.com/vboard/s...d.php?t=545416

The first few pages are a table of the GM circuit numbers with the corresponding colors and functions.
The bulkhead plug positions and other termination point pinouts are identified by GM Circuit Number in the big foldout pages.