having issues truck is DOWN...

2000 VNL 770 n-14 1st gen auto shift 977,750 miles (has the clutch pedal and the shift tower with a manual type shift selector (not the pushbutton type)

had a coolant line down to the transmission split- lost a few gallons of fluid. fixed that. the original oil/ coolant tube at the back of the transmission has been bypassed by previous owner- looks to be very badly corroded.
SO- alternator decided to go bad- had it rebuilt. and at recommendation of rebuild shop, I left the little "I" terminal wire with some sort of capacitor or diode built in it, off the alternator. wire is about a 12 gauge size about 6" long.
NOW I cant seem to find that wire..

since then- I have had the telltale battery light on on the dash... alternator is putting out 14.1-14.2 volts. same reading at batteries. all battery terminals lugs etc are very clean. I checked the ground lugs at the chassis, back of the starter, battery box, and other ground locations while crawling all over under the truck.. I checked for any loose wiring harness connectors, and In the process cleaned with electrical contact cleaner and put die-electric grease on them.

What is the purpose of that little "I" terminal wire that had some sort of capacitor or diode with it? and where can I get a new one at?? anyone know? is it critical for the truck and the electronics?

since alternator rebuild time-and missing that wire,... im now having issues with numerous codes pulled manually from the transmission. (via service light) 35,41,56,57,86. its not playing nice when shifting from 2nd-5th. the higher ranges shift and work fine, when downshifting- below 5th it wont downshift- and skips down to 2nd. reverse works fine- truck starts fine. the x-y shifter was replaced just before I had purchased the truck.

I have NOT had any issues/ codes etc until the alternator went bad (bearings actually). since that time- I cant get the truck to run right to go get a load.
of course the dealer says- "bring er in" at $97 hr, and we will TRY to figure it out..." problem is dealer is 70 miles away in a LOT of stop and go traffic. NOT fun with a truck that wont drive right. and Impatient 4 wheeler drivers. TOW bill is ridiculous for the distance. ;o( and I try not to give my hard earned cash away to the shops if I can figure it out myself or with some help...

Tips- ideas, solutions, and any idea on where to get that "I" terminal wire at? tips on the other issues???? help would be greatly appreciated!!!

 

ALSO-- Found that the 10AMP spade fuse next to (directly behind at upper corner) the ECM was blown??
Another individual posted the exact same issues back in 2010-11? but no one posted the results or what was found to be the culprit..

Terminals/ wires on starter are clean, batteries are clean, etc..?? IDEAS???

 

I checked all the grounds I could find outside the cab (on the chassis) starter, ECM and as I checked for grounds, each connector. splice etc, I sprayed with electronic cleaner spray- and then applied a very small amount of dielectric grease on those connectors etc. I did NOT apply Die electric grease to battery terminals.(OR THE ECM plugs, they are clean, no corrosion etc at all on them, batteries are from Nov '13.
As I was doing all the wire harness checking- the Batteries were disconnected for about 2+ hours. I went thru the truck in that time checking wires, then connected the batteries back up. turned the key on- NO caution lights, no service light- Thinking GREAT.. Fixed it... took it for a very short drive- less than 1 mile.-- same issues. and codes flashed from service light again from shift tower on autoshift. =o( driving the same as before. truck starts and idles fine, will rev fine, but shifting is the issue at hand....Only fuse Im finding Blown is the one directly behind the engine ECM. and it only blows afte starting the truck. KEY on- not started, that fuse does not blow. Im unable to locate ANY inline fuses to the transmission ECM.
so the truck has sat for a week now, as I ordered a battery load tester, transmission cooler, and a HD OTC code/ scanner for the truck.. maybe this week I can get back to the truck and see what's going on. Perfect Timing I guess with this winter storm that we just got hit with.. 8" snow here locally.. and seen -16* this morning BRRRR

ON another note- called VOLVO on the alternator wire-- --GET this-- "I have no clue what that wire is, What the thing is in the middle is,... if its a diode or cap or what it is...Nor can I get you one, but it comes with the NEW alternator for a nice discounted price of $349.99 thru Volvo..." this was the parts AND service personnel answers.......... separately!!!

 

Found and fixed transmission shifting issue-- OUTPUT SPEED SENSOR- replaced it with a new one, took about 45 minutes. truck runs good and shifts nicely now... the OTC code reader paid for itself already. and I have learned more about my truck...

To test a speed sensor- use ohm meter and check the terminals in the sensor plug in- should read .2*** ohms approx.. or it will read- grounded out. some trucks have 2 sensors on the output shaft, at approx. 10 o'clock and 12 o' clock positions above the yoke on the back of the trans. compare readings between the 2 sensors. replace the bad one- they easily twist out with a light pull, most are NOT threaded in, only a simple "O" ring holds it in place. sensor for my truck was $35.00 and comes with some copper anti-seize to install it.


Still working on the battery light on the dash- as I installed a new resistor diode wire on the alternator-..light is still on.....will figure that out...

I'm going to change the wiring on the engine ECM.. as its has + power all the time, instead of running the power wire from the starter solenoid to the ECM, I'm going to run a fused dedicated wire from the battery box to it, and a new ground wire.

Batteries all load tested - check out fine- alternator putting out 13.7 -14.2 volts, charging system is in good shape..

I wanted to post this follow up so that others who may have the same issues can possibly get it fixed without paying out $$$$$$ to a dealer when they could possibly fix it themselves.

 

Thanks Jim,buds.. Guess I was lucky that I broke done in the yard, and not the middle of BFE.

The code reader is a OTC 3418.
I found at http://n14parts.com/index.php?route=product/product&product_id=57

The info on testing the sensors I found at wellertruck.com digging thru their tech support manuals. for the GEN 1 auto shift. And doing more digging on the internet...