Help on wireing please?

[BOSS]

Hey guys as some of you know i am trying to get the engine running on the 4x4,I just about have everything hooked up but i am haveing trouble with the wireing.I cant seem to get power to the starter(it does kick in when i cross it at the starter),It is a different harness that i got from a board member and i think it is all there.I have tried the diagram on the net to track all of them and cant get power to just about anything,The dome light and one park light,and the dash lights are about the only thing i can get to work.Can i take a short wire and cross the purple and red wire at the switch and get it to crank that way?On the starter is it just the purple wire that is on the right side and the large one that comes from the batt?Where can i get the hot wire for the hei?This harness had it for the points.How do you hook up for the new style alt?I am sure that i will have alot more questions soon.......Thanx for any help you can give.I just wish i could afford the painless,cause this is starting to hurt........lol

[Robert1970C20rstbukt]

What year is your truck and what engine is in it?

[BOSS]

72 4x4 and i think the engine is a 85 350

[Don R. Dodson]

James, a word of caution is in order for you. As an Electronics technician, I can witness the results of trouble shooting electrical problems properly. Needless to say that you aren't allowed to go after electrical problems with the same attitude that one approaches mechanical problems. You can try to put a wrong size nut on a bolt, and nothing is harmed. You can even try to put a round rod in a square hole and nothing is harmed. But you take a 80 amp battery and try a wire here or a wire there and you have 80 amps possibly going into a short or a 2 ohm load, and a 2 ohm load with 80 amps of current is 12,000 watts of heat. 80 amps with a one ohm load is 6,400 watts of heat. I hope you can see that much heats is FIRE. You are not allowed to experiment with wiring problems the same way as you are with mechanical issues. You MUST get the proper wiring diagram, and what I mean for that statement is a wiring diagram for what you are working on, so that you can follow the wires from the source to the other end to insure you have the wires connected correctly. Use a analog multimeter (ohm, voltage, amp) to help trace out the wires to their connections. It seems obvious that you have a wiring problem, and so far you have been lucky by not seeing smoke.
No one will be able to fix your problem on line in this forum because tests will have to be done using proper techniques for electrical trouble shooting. Hopefully you can find someone locally who can help you get to the root of your problem by using proper test equipment and understanding how to read electrical diagrams. Some of the vendors shop manuals in the electrical sections are a disgrace to the electrical industry. Case I just saw yesterday was a Chevelle wiring diagram. Won't go into the details of the Chevelle stuff, but you had to look for what page to go to next and lost track of what it is you were looking for. Couldn't follow a wire from one end to the other, and I have been into this stuff for 41 years. Good Luck!

[cdowns]

first place to check for your power lead is up by the battery on the fender there's the lead from the positive battery terminal(PICTURE)
now the purple wire from the ignition switch goes to the neutral safty switck then to the starter
as far as the hei wiring ,i just went to the firewall connecter where the original distributor wire was fed from you pull those wires out and run the new wire from that spot on the junction box ,when doing the hei you eliminate the yellow wire from the starter to the distributor
when doing wiring one of the most important thing is GOOD GROUNDS!!!!

[FRENCHBLUE72]

Way to help out someone in need don r tell them they can't get it fixed by asking someone online in this forum!!!!!! We have a great wealth kowledge on this board and helping out people in need is what this board is all about try to offer some positive advice and not negitive.....

[cdowns]

Originally Posted by FRENCHBLUE72

Way to help out someone in need don r tell them they can't get it fixed by asking someone online in this forum!!!!!! We have a great wealth kowledge on this board and helping out people in need is what this board is all about try to offer some positive advice and not negitive.....

my thoughts exactly!!!
on a side note why is it that technicians,engineers and teachers seem to need 500words or more to say: DUH,I DON'T KNOW

[dubie]

You should runa hot wire from your IGN Unfused spot on you fuse box directly to your HEI. Take the purple wire from the wiring harness and connect it to the start post on the starter, it's the one closest to the block. Hook up the positive battery cable to the starter and make sure your power lead as pictured above is in place. I grounded my negative battery cable to the alternator bracket and she fired right up. Let us know how you make out bud

[BOSS]

thanks guys for all the help (and even those that didn't offer any help). I had to work on my brother's axles tonight so I will try it tomorrow when I get in. thanks for all your help again and I will let you know how it goes.

[Blue68]

James,
If you haven't done it yet, spend a good bit of time tracing the wires on the wiring diagram. It is definately tedious and a bit aggravating when it spans pages, and you'll have to find wires that actually match colors coming from the bulkhead connector in order to figure out left from right. But the time spent will be worth it. I wired my own under hood harness because I felt aftermarket was too expensive, and I'm not running much of anything stock under there. I put in relays for the headlights, hei, electric choke, higher amp alternator (on the other side) etc, so hacking up a good OEM didn't make sense either. But I spend several hours here and there pouring over the diagram until it made sense. Trust me, some if it doesn't for a while. The ammeter loop is one of them. Another is the reasoning for having the distribution block (major connection point) on the driver side when the battery, and alternator (stock position) are on the passenger side.

Also, you might want to try tackling one wire/component at a time. It'll be easier on you and you'll get more/better answers on the board. HEI is a good example here, as is which wire goes to which post on the starter.

You may need to go further back and check to see if you even have power to the ignition switch. If this is an automatic, cdowns has a good point to check the neutral safety switch, if there isn't one, or it's not in the correct position, in the automatic harness, that's a problem.