1972 Scout II Engine Wiring

Discussion in 'General IH Tech' started by MrMag00, Oct 8, 2004.


  1. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi
    I have a few Questions and hope that someone can help. I am in the process of helping a friend we are fixing up a 1972 Scout II 345 V8. The issue we are having is that under the hood it looks like spagetti from the firewall. One of the 2 plugs that come out from firewall is gone and wires simply hang out of the hole :eek: . I see a Gold box on the fenderwell (pass-side) which is not hooked up ? I cannot find a voltage regulator anywhere on either firewall :( . He said he had it running...I am suspect that someone came to "help" him who was totally clueless and may have removed things. I do get voltage at coil so a charged battery and new starter are first and will be installed tommorow.

    I have some scans of wiring harness pinouts for firewall plugs but it is for the electronic ignition, the second diagram I found shows voltage regulator in the system. I think this thing is wired without it :confused: ? Is that possible :confused: ? I know it may run for awhile but I wouldn't think it would not start more than a few times with a battery that doesn't get charged ?

    I am looking for picture(s) a diagram maybe :rolleyes: from a current owner of a 1972'ish Scout II showing wiring under the hood/gauges. I need this because I think I am going to pull all the wires out and start fresh with a "Painless Kit" though that will have to wait untill January of next year. At this time It needs just to run to get it 50-70 miles back to a shop to work on it.

    I have Service Manual #'s but am skeptical about purchasing because of what I read about how confusing the wiring diagrams are.

    I have Painless Kit #'s ready to order but if this thing blows too much smoke or it runs bad maybe other things need attention first.


    Any help you veterans can give is appreciated in advance
    Have a good day!

    MrMag00
     
  2. SCscoutguy

    SCscoutguy Moderator Staff Member Moderator

    Joined:
    Jul 25, 2004
    Messages:
    5,281
    Likes Received:
    7
    Trophy Points:
    38
    Location:
    Florence, South Carolina
    This is probably not any help but a 72 Scout II shouldnt have electronic ignition. It sounds to me like someone took a Holley gold box system out of a later Scout II and put it on your truck. I had a 77 Scout II with the gold box and it is the work of the devil I was always having to replace them. If I was you I would just make sure what dizzy you have and see if it has points or not. Then once you have that down just hardwire it to crank and run it that way to get to the shop. I have a 72 Scout II that has the same problem yours does under the hood looks like a rats nest of wires, I just made my own little harness to get it started I will worry about everything else later. Good luck and let us know how it goes.~John
     
  3. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi
    I swapped out an engine in this truck about 9 yrs ago and then the kid blew it up it passed owners 3 times and made it's way back into my life with another IH original engine that amazing I think :) .


    I though that might be the best way to get her back on the road using some of the existing wires but at almost 50yrs old I fail myself with all the information I need could you type out if you would a quick start run diagram, I believe I just need hot from starter to coil then to dist to get it up and running but I am not sure and it was a long day at work :eek: .

    Thank you for the quick reply anyone else who reads this and wants to add any quick circuit making hint/tips feel free! I need your input here.


    The pictures I have are from a 77 with electronic ignition and a one page diagram from a CTS-2218 manual thats not even close.


    MrMag00
     
    JWolfe likes this.
  4. ScoutmanSV

    ScoutmanSV Y-Block King

    Joined:
    Oct 11, 2001
    Messages:
    3,788
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Central Sierras/Squaw Valley, CA
    If it has a GM alternator w/the 2-pin plug-in > internal voltage reg. ;) That's what most of us run & stock goes to 85amp. IIRC, there is a Caddy 135amp, but it is a tad larger diameter & requires a different bracket/belt.

    I've got a '73 I'm working on & the wiring is pristine. Trouble I'm gonna have > the '77 the engine (points) came from was in the same shape as yours & I ran toggles/push buttons & my own wiring. That's all still on the engine & I think I'll leave it .... who needs a key switch in a 4x4. :D I will connect the appropriate 'hots' for the dash guages/switches tho'. That *should* be easy as there are only 2 'hots' thru the firewall, IDB.

    Since charging is your prime concern: see how many wires/connections for wires the alt has & if mine is the same > I'll post back the routing of the wires for ya. Then we can work on what other starter wires are needed for cranking the starter & the ignition.

    Dash wiring, brake lights & the like are a pain & not my forte at all. ;)

    HTH,
     
  5. SCscoutguy

    SCscoutguy Moderator Staff Member Moderator

    Joined:
    Jul 25, 2004
    Messages:
    5,281
    Likes Received:
    7
    Trophy Points:
    38
    Location:
    Florence, South Carolina
    You pretty much spelled it out that is basically all you need to do to get it going. Make sure the alt is working and charging the battery I did just what you were talking about and it ran for a while on the bat and then it just died because the battery died. Maybe someone can chime in on a better way to do it but I bet you can get it running just take your time and buy a spool of extra wires and connectors.~John
     
  6. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi


    Thats just what I am going to do run it plain without any acc at all I will have someone following me back for brake lights etc. It looked like a new coil and a newer Alt and the other post a minute ago reminded me that the regulator is in the Alt it's the GM 2 wire I will just wire that back to batt with some new wire and make sure when key turns I get voltage at coil. Also unconnecting all the other wires in one swift cut :) I suppose a push button might work maybe a old light switch hi/low beam I can screw to the floor for the start circuit not sure what I will do either that or a screw driver key system :D

    Thanks again for your replies maybe this can help some stranded guy in the future.

    For anyone that reads this is not a hot start issue I already know the truck has that problem so were going with a new starter and a firewall mounted solenoid later on :) .

    One more time "Have a good day!"


    MrMag00
     
  7. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi


    Looking at the Alt I believe your right it looks like the GM 2 wire plug plus the main 12ga? wire. If you could post me some more goodies I would greatly appreciate it to be better prepared because this truck is 50-70 miles away from any computer...city I think is about 15 miles so when I get there I want all the info I can have with me plus my trusty but rusty :D tools. Thanks in advance for information.


    MrMag00
     
  8. Thomas

    Thomas Dreams of Cub Cadets

    Joined:
    Jan 24, 2002
    Messages:
    4,739
    Likes Received:
    25
    Trophy Points:
    48
    Location:
    Friendship, WI
    ---The wiring diagrams are in no way confusing. The problem is that they break down one complete diagram into seperate systems (i.e. startring/charging, interior lighting, headlights, etc.) and if you terminate a wire, you might have actually neede to terminate two or more wires. The only thimng to do is follow the wiring digrams and don't terminate anything until you have each wire run to and from its location. There is nothing* wrong with the wiring diagrams, it is the person doing the wiring that can't read blueprints/diagrams ;)
    ---I have heard too many bad things about the wiring systems they have (i.e. wires being too short and them not accepting a return because they say you* cut it), I wouldn't even consider them. If all you want is an engine harness, maybe Super Scout Specialist has one that is OEM. Good luck getting the correct terminals for the gauges from Painless.

    ---Your bud's vehicle will only use the "gold box" if he has a Holley electronic ignition, which I doubt with it being a `72... not stock anyway. If the distributor has points, it most undoubtably is not electronic ignition and what you are looking at might be a Decel Throttle Module. DTM is either half the size of a cigarette pack and metal, or the size of a 100s cigarette pack and plastic. A gold box is the size of a 100s cigarette pack squared, about the same size as a Duraspark module for a late model Ford (AKA "black box").

    ---I believe a `72 would have had an external voltage regulator, my wiring diagrams even show it for a `78 and I know* a `78 didn't have one, so looking for the voltage regulator shouldn't be on he list. Now, all this is not saying that someone didn't change some components, they could very well have went with a Holley ECM and tossed the points dizzy, but I doubt they went with an alternator with an external regulator... unless the alternator is a Bosch unit... housing has slots all throughout it and could resemble an old time house/office fan's cage.

    ---I'll give you everything on that bulkhead connector and hope this helps:
    • Looking at the bulkhead connector from the engine compartment:
    • Top left #71 - 18 gauge to the backup light switch
    • Second terminal on the backup light switch goes to the terminal just below #71 (bottom left) - 18 guage and labeled #71a
    • Second from the left, at the top is #75a - 16 gauge for Red wire on heater blower motor
    • Orange wire on heater blower motor is also 16 gauge labeled #75b and running to the second termninal on the top right hand side
    • 1st terminal on the top right is #16 - 20 gauge and runs to (+) coil resistance wire of 1.8 ohms - - - Also terminated at (+) coil is "R" on the starter solenoid labeled #16a - 18 gauge
    • Center top is #2 - 10 gauge and runs to "B" on alternator, this is the ammeter (-) side from the dash
    • Bottom right terminal is the oil pressure sender circuit #35 - 18 gauge
    • Bottom, second from left is #17 - 14 gauge to the starter solenoid "S" terminal
    • Bottom center is #14 - 10 gauge to the starter solenoid "B" terminal
    • Second terminal from the right on bottom is #29 - 18 gauge and runs to the temp sending unit
     
  9. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi

    What you have stated about the harness wil be considered greatly I have read a bunch of things about them Maybe it's time to get some spools of wire and a fuse block and sit there and wire up my own harness that would be the best way to fix alll problems at once and save $ because they wanted $350 for the 12 circuit harness I can get the fuse block from my Uncle who runs a GMC dealership and wire from a electric supply house I know a old friend has. Thanks for the inspiration I think I will order the Service Manuals from Binder Books then.

    I had him go look at alt it is the GM 2wire plug that comes out so it's internal.

    Your description matches my printout exactly but it does show a Electronic ignition in the scan I have the truck has the heater box removed it's in the back seat none of the sending units are connected on the engine but the wires look like I will be able to get it up and running with the information given by you and the other people who posted.

    As far as what I thought was a "Gold box" and to what it really is...it's about 5 inches square and 4-5 tall... large heat sink on top so maybe it's not the gold box but just a spark kit I remember putting one like this on an old 1970 Toyota i had once for ignition.(add-on).


    Thanks again as this will be hard enough being so far from a parts store.


    MrMag00
     
  10. Thomas

    Thomas Dreams of Cub Cadets

    Joined:
    Jan 24, 2002
    Messages:
    4,739
    Likes Received:
    25
    Trophy Points:
    48
    Location:
    Friendship, WI
    ---If this is what you are looking at, it is a "gold box"
    [​IMG]
    ---Installing a heat sync is a popular idea, but it doesn't completely solve the problem with the Holley ECM. The problem isn't solely because of heat, it is generally because the grounds are bad and/or the ignition switch is left in the "ON" position with the engine off.
     
  11. lilbluescout63

    lilbluescout63 Farmall Cub

    Joined:
    Jan 14, 2003
    Messages:
    179
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    empire
    wen i got my 72 it woudnt run no lights nuthin i did a quick 10 min job of wiring just so see if the ol girl had spunk stil after 5 years of sitin out back :mad: .and a wana b carb that i had to re build didnt help its a pos but it pors out the gas it suposaly use to run yep it did and it was a stinky messy smoky experiance lol all in so i got out the wir harnes un did all the tape because the # and coolors wern the same coolor now and than went threw the whole under dash- engine once i figured out how to folow a whire from a - b and figure that plug out it worked out fine was my first under dash ive done found out the 2 + on the fire wall were reversed and than thought y didnt i just take readings from there it wouda saved me a tot of time but now i have experiance ansd it be simple to make one . sory i forget the ............. a lot i know yall hate that .i have a spare 79 harness i dont see mutch difrence in the two. so what id do just to get it to whair it has to go seeing you dont need lights exc. wire the bat- to -alt - batry -to -starter - relay on starter to -dist or wire the coil -to -bat but to do that youl need points and condencer and a coil . nice to have parts or know some one with them than just get out that golden screwdriver just dont forget to disconect it all or the coil wil blow .and to stop lol how do you stop a auto if its a auto. lol humm it dont got a clutch and pedal hu lol wel you can disconect the starter from the batry or disconect the coil as it wont have spark to ignight or cover carb and starve it
     
  12. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi
    This morning I go

    This morning I take off to go fix that thing I hope this works out. Thanks again to all you for input. I think I will bring a camera and post some pics of the dead Scout :rolleyes: being revived! and maybe one of the classic Scout wiring under the hood :D . Have a good day ! I know mine is going to be busy.


    MrMag00
     
  13. harleykeith2003

    harleykeith2003 Binder Driver

    Joined:
    Apr 6, 2003
    Messages:
    813
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Ardmore Oklahoma
    You can try the E Z Wiring its about $165 for I beleive a 21 circuit
    they have a web site and I called them awhile back--they seemed decent----
    plus a few people on here have used them
     
  14. MrMag00

    MrMag00 Farmall Cub

    Joined:
    Oct 8, 2004
    Messages:
    8
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Grand Rapids,Mi
    Followup With pics 1972 Scout II Engine Wiring

    I found the Scout II sitting waiting to run....

    [​IMG]


    Then I saw the wires...

    [​IMG]
    [​IMG]
    [​IMG]


    After a bit of looking I found this

    [​IMG]


    I bet it won't start with a starter that looks like that :)

    I then put back the wires after adding many new ends and patching the ones that were melted to the exaust manufold :eek:

    [​IMG]
    You can just see the new starter down there cool!

    [​IMG]


    Thats about it I have more questions if anyone reads this maybe you could add some input.

    I think I have a "no Charge" situation I checked voltage at batt when the engine ran same 12.5 as when engine is off. So I went to the Alt and checked voltage at the 2 wire and the main lug on the back...I got the same 12.5 on the big wire and a whole 2 volts at the 2 wire plug? This is a bad alternator no? Anyone who throws some input here would be greatly appreciated.


    I will be having some fun posting the updates to this old truck as they happen. Have a good day!


    MrMag00
     
  15. JWolfe

    JWolfe Farmall Cub

    Joined:
    Feb 13, 2019
    Messages:
    57
    Likes Received:
    3
    Trophy Points:
    8
    Location:
    Dayton, Tx.
    Could you send me that diagram ?
    I have a 77 scout 2 that is kicking my tail, I've been ride free for months can only do so much at a time on VA disability. Godbless
     
  16. scoutboy74

    scoutboy74 Lives in an IH Dealership

    Joined:
    Mar 10, 2004
    Messages:
    5,881
    Likes Received:
    630
    Trophy Points:
    113
    Location:
    Daze Crick, Jefferson
    Mr. Wolfe, this thread is from October of 2004. That's the last time there was any activity on it before you revived it this morning. The Light Line vendors have factory service manuals available for purchase which contain the wiring diagrams and a host of other valuable information. You need the one that covers your year of vehicle, as changes were made to the SII electrical system over the years. They aren't all the same from beginning to end. The manuals aren't cheap, but they're worth the money. I appreciate your service and also appreciate that funds may be tight in your situation. So in the meantime, maybe someone reading this can help with a pdf scan or two from their 1977 manual. I don't have that year of Scout.
     
    TorqueMonster1 likes this.

Share This Page