More opinions needed! 2 steps forward...one step? - Page 2
 

More opinions needed! 2 steps forward...one step?

Started by daddysgirl, November 26, 2016, 12:57:07 PM

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gumpy

Quote from: daddysgirl on November 27, 2016, 02:27:48 PM
The ONLY thing I did on the starter is change the cable to positive stud on the solenoid and the cable to ground on the end of the motor (After a test directed by MCI tech, I didn't remove a wire and burnt up the starter cables...see earlier post). And thanks for your help. I'm not trying to be argumentative...just typing what is actually there.

What test are you referring to that the MCI tech had you do, and what was the wire you forgot to remove?  Maybe I missed it above.
Craig Shepard
Located in Minnesquito

http://bus.gumpydog.com - "Some Assembly Required"

daddysgirl

That wire, the one that has the melted terminal, was exposed last year. I covered it in 2 layers of heat shrink tube.
I'll try to get some pictures uploaded tomorrow so you can see it.

And looking at one of those pics, I can see where the L strap would go to the up terminal. It just looks really bad. The pic was taken a while ago.

The tech had me put the start wire on the + solenoid terminal. The main power cable was NOT connected.
Afterwards, I got distracted and when I connected the + cable, I didn't remove the wire. Never will be distracted again. BUT nothing other than the starter cables and my ego...was damaged.
Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-

brmax

The starter signal wire on the solenoid needs safely removed and further circuit test to clear up the incorrect wiring and there is.

The battery+ wire at starter needs removed and taped to prevent shorting and tied off securely.
 
This has been getting nowhere, safety matters and re wiring this by the book/schematic is the best direction. 

I'm very curious of prior test mentioned, this post is separated on other post so before anymore recommendations reviews should be made.

Its best to get a proper meter and test lights and with capabilities carry out steps or test some may mention in circuits and have mentioned.

the up connector is from the starter body to the solenoid shown in this pic

Floyd
1992 MC9
6V92
Allison

daddysgirl

Hi Floyd.
If you'll tell me how to post a pic, I'll show you.
The problem with further testing is that the power cables coming from the battery no longer have copper ends. they melted. The starter cable is fine, but the 1/0 is gone, and the 4/0 is melted to the washer. I'm not willing to chance another fire with all of the dry air, but prior to this, I did take each wire off and test them both under no load and while Logan was pushing the start button. They were fine, as were the rear box connections.

But (and this is only what I think) when I pushed the starter button, it started spinning. When I let off the button, it didn't stop. I had to kill the battery switch. And the wire connected to the signal terminal on the starter is one of 2 neutral safety switch wires, NOT the starter wire.
Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-

daddysgirl

Hey Craig.
Questions:
I have both sets of schematics, but there is only one with the 2 wire NSS and because my tranny was new in 2001 I can't use the unit number for that. But I do use the motor control so I can understand where the 1974 wiring is routed.

You mentioned the connection on the three cables being loose. I do remember it was not as difficult as it should have been to remove the nut from that bolt. All three cables were connected, but if there was a tiny bit of space between the 4/0 and the 1/0 could arc have caused them to get that hot, and leave the starter cable unscathed?
Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-

B_K

First off listen to Floyd and Craig.
Second don't have it towed! Only thing that will do is make a tow truck driver some $! the shop is only going to do what you can do yourself!

OK Now if it were me, I'd go back to square one.
First thing to do is remove ALL wires from the starter and ohm it out.
Also remove the three wires from the stud where the one melted! OHM all 3 out and see if one is supposed tobe a ground, or accidentally grounded.
Next find out where/what each of these 3 wires is. I suspect 1 is hot coming from the batteries. 1 is the hot wire going to the starter. And most likely the 3rd is coming from the main terminal on the Alt. to charge the system when running. (probably the 1/0)
Next use test light to test power on the wires going to the starter. But as Floyd (or Craig) suggested leave the signal wire unhooked while testing turning the power on.
If you can turn power on and all is well then touch the signal wire to the solenoid.
If the starter cranks w/o pushing the starter button that wire is getting power from somewhere it's not supposed to.
If it doesn't crank w/o pushing the starter button the wiring is correct.

NOW if the starter is bad YOU can change it yourself!
A 12 point socket will loosen the starter bolts, take the top one all the way out since it's the hardest to get to.
Then before taking the other two out get a floor jack and jack it up under the starter.
Once the jack is in place remove the other 2 bolts and the starter will be on the jack where you can lower it.
If you have to buy a new starter anyway might as well go a head and buy a 39MT and make it easier on yourself replacing it now and in the future!
;D  BK  ;D

B_K

BTW attaching pics is not hard if the are small enough.
Just click on the additional options box in the lower left corner when  making a post.
;D  BK  ;D

(biggest issue is resizing them small enough to post!)

daddysgirl

Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-

daddysgirl

OK.
The starter wire is not here...it's OK.
The wire on the right with no end is the 1/0 that goes to the rear junction box stud. The other (welded to the washer) is the 4/0 that comes from the batteries.
Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-

Oonrahnjay

Quote from: daddysgirl on November 28, 2016, 06:35:05 AMOK.
The starter wire is not here...it's OK.
The wire on the right with no end is the 1/0 that goes to the rear junction box stud. The other (welded to the washer) is the 4/0 that comes from the batteries.   

    Are these hot wires, switched wires, or grounds?  I'm confused!
Bruce H; Wallace (near Wilmington) NC
1976 Daimler (British) Double-Decker Bus; 34' long

(New Email -- brucebearnc@ (theGoogle gmail place) .com)

gumpy

Quote from: daddysgirl on November 28, 2016, 05:55:36 AM
Hey Craig.
Questions:
I have both sets of schematics, but there is only one with the 2 wire NSS and because my tranny was new in 2001 I can't use the unit number for that. But I do use the motor control so I can understand where the 1974 wiring is routed.

The switch is just a switch. It doesn't matter if the tranny is from the 70s or 2001. Use the schematic for you model number. The wiring should all be there even though it was a manual transmission originally.

The problem is that in order to fix this correctly you need to rewire the starting circuit and use the relays as they were intended. Currently you have positive going through the NSS directly to the starter, and it should have ground going through it to the relay.

I think you should probably worry about getting the starter and cables fixed first. Obviously what is there has been working for several years. Just need to figure out what got screwed up recently. Chances are good the starter is stuck or the commutator is bad.


Quote
You mentioned the connection on the three cables being loose. I do remember it was not as difficult as it should have been to remove the nut from that bolt. All three cables were connected, but if there was a tiny bit of space between the 4/0 and the 1/0 could arc have caused them to get that hot, and leave the starter cable unscathed?

Of course. Arcing inside that stack would melt things in a hurry. Think arc welder. I don't know the order you had the cables, but it's certainly possible. Corrosion on the cable ends can cause heating, also. Basically, those cables need to me clean, tight, and making maximum contact to each other, with no contact to the frame. Make sure that stud was not damaged, also. The threads have to be good to get a tight connection and the stud cannot be loose in the insulating mount. If it is bad, replace it. You saw the damage that can happen by the arcing. You're fortunate there wasn't oil in the immediate vicinity.

Craig Shepard
Located in Minnesquito

http://bus.gumpydog.com - "Some Assembly Required"

gumpy

Quote from: Oonrahnjay on November 28, 2016, 06:41:03 AM
    Are these hot wires, switched wires, or grounds?  I'm confused!

These are positive cables from the batteries. The burned one is the alternator cable.

Yes, they are hot. As you can see, that one was really hot!  ::)
Craig Shepard
Located in Minnesquito

http://bus.gumpydog.com - "Some Assembly Required"

Oonrahnjay

Quote from: gumpy on November 28, 2016, 06:52:18 AM
These are positive cables from the batteries. The burned one is the alternator cable.

Yes, they are hot. As you can see, that one was really hot!  ::) 

      Thanks.  Color coded black on that model of bus?
Bruce H; Wallace (near Wilmington) NC
1976 Daimler (British) Double-Decker Bus; 34' long

(New Email -- brucebearnc@ (theGoogle gmail place) .com)

daddysgirl

The colors correspond to the colors of the cables in the battery compartment. The battery kill switch as a positive cable just under it that supplies power to the two cables above. One (red end) goes to the stud in the picture. The other (blue) goes to the AC junction box. The negative goes up the wall to it's transfer cable, but it has no color on it.

Ok. Thanks for confirming my thoughts Craig. Now at least I know what caused them to melt.
I can have a new 1/0 cable made, and I can re-route it. I'll need to remove the oil bath air cleaner to be able to reach the terminal stud on the rear box (that cable is connected to that stud, along with the alternator cable)
IF (BIG IF) I can get the starter off...I can take it apart and see how bad the disc is...I could even get the kit and rebuild it. I'm totally comfortable in my abilities at that point. Where I'm shaky is getting the darn thing off.
Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-

daddysgirl

Craig:
Just so you know my procedure...
I always make sure to replace everything in the order it came off. With any wiring, I take a picture, tag every wire, and keep a master notebook where I write it down as I'm working. That stud had the large 4/0 on first, the smaller 1/0 on top of it and the starter cable on top of the 1/0. You can see the size of the washers. They are all original, or I should say were, as now 2 of 3 will be replaced.

You are (of course) correct that all of the wiring is still there. The reason I mentioned the schematic is because the only one that shows the routing of a two wire switch is the auto transmission HT740D effective with unit 30514, July 1979.
The schematic for 30048 only has a one wire switch and no connection to stud 26. The fast idle side is the same from what I remember, AND for the life of me, I have looked EVERYWHERE and I can not locate the terminal block stud (with the 8 connections). I have uncovered a few studs, but they are not labeled....OR the cradle harness plugs that show A, B, C, D...so I can follow either of the schematics. I mention this because those points usually show the ground and I'm anal about making sure all is grounded properly.

However, you make a good point that none of that matters until I get the starter and cables back working as they should.
Andrea   Richmond, VA
1974 MC8 8V71/HT740 new in 2000 and again in 2019-