My 1008 is making me go bald!

[mangus580]

Your wiring looks like it has been adjusted at some point.

 

[BobM]

Your wiring looks like it has been adjusted at some point.

Yeah I was afraid of that. The original ground wire was broken off and the large ground wire was added. Why they didn't remove the eyelet and broken wire I have no idea! You can see the temporary end I put on the ground wire at the intake manifold in the far right of the pic. I want to replace the whole groundwire since the wire itself is slightly corroded.
Any idea what the extra brown wire on with the red wire is for?

 

[m4A1]

The plastic plug has two 12v source wires, the one connected to the output lug is the exciter wire that excites the coils so the alt can create electricity and the other is sourced through the gen 1 light and the alternater provides a ground if there is a problem. if the wire connected to the output was disconnected your alternator would not charge your batt.

 

[Michael]

The extra brown wire goes to the tach buffer module and is part of the diagnostic circuit. It is not needed for the proper running of the truck.

Your picture shows 6 wires attached to the alternator, The TM only shows five. Where does the extra black wire attached to power output stud (the big red wire) go?

 

[BobM]

The plastic plug has two 12v source wires, the one connected to the output lug is the exciter wire that excites the coils so the alt can create electricity and the other is sourced through the gen 1 light and the alternater provides a ground if there is a problem. if the wire connected to the output was disconnected your alternator would not charge your batt.

The small wire that wasn't making contact because of a dirty connection is the one on the left side of the plastic connector. The other wire coming out of the connector is a fusible link.
The wire I left off during one of my MANY cleanings is the smaller brown wire hooked on the lug with the red wire. I have had it on and off since I got the alt working and can find no difference whether it is on or off. The wire disappears into the factory loom and heads for the firewall.
I could not find any reference to this wire in the wiring diagrams.

 

[Michael]

I have been doing some more studying and it appears there is suppose to be a black with white stripe wire on the ground post that is also part of the diagnostic circuit.

That means that the TM shows 6 wires and you have six wires, one is just in the wrong place. Good thing you don't have the diagnostic computer to hook up to it. I bet it wouldn't like 12v plus were it expects ground.

 

[mangus580]

I have been doing some more studying and it appears there is suppose to be a black with white stripe wire on the ground post that is also part of the diagnostic circuit.

That would be correct...



It looks to me like maybe someone replaced the plastic plug on his, that would explain why the wire colors dont match.

Bob, the dirty connection you speak of on the 2 wire connection would explain all your problems. That wire is what manages the excitation of the alternator, and that is handled through the Gen 1 light. I would get some contact cleaner, clean it up, and put some dielectric grease on it.

The small wire you have with the large red one on the stud... is as Michael says, a ground wire for the diagnostic circuit. You are lucky that you didnt short something out with it.

 

[BobM]

That would be correct...

View attachment 101698

It looks to me like maybe someone replaced the plastic plug on his, that would explain why the wire colors dont match.

Bob, the dirty connection you speak of on the 2 wire connection would explain all your problems. That wire is what manages the excitation of the alternator, and that is handled through the Gen 1 light. I would get some contact cleaner, clean it up, and put some dielectric grease on it.

The small wire you have with the large red one on the stud... is as Michael says, a ground wire for the diagnostic circuit. You are lucky that you didnt short something out with it.

WOW! Am I glad noone around here had a Diagnostic Unit. That would have left a mark.....And maybe some ashes! Makes you wonder who works on some of these. Because my story is that the wire was always under the red wire ever since I got the truck....And I'm sticking to it!
This truck had a dead front battery when I brought it home. The wires on the left alt looked like they had recently been disturbed. That makes me feel that the charging issue was a recurring problem.
BTW I made another night with no glow from Gen 1's light....However Gen 2 glowed very dim at idle as I pulled into the garage. there was a faint belt squeal when I revved the engine, so I hope it is just the new belt getting stretched.
And even tho noone will probably EVER put a Diagnostic Unit on it, that wire WILL be changed!

 

[beaubeau]

It sounds to me like the Exciter wire may have an issue some where in the Harness. Be sure the wire is good at the Alt. Hook up. I think I lost quite a bit of Hair this week with Glow plug issues. I finally changed one M1008 to manual and by using "THE card" from one truck and installing it on my other, I got the glow plugs to work good on Both trucks. Good luck, Phil

 

[BobM]

It sounds to me like the Exciter wire may have an issue some where in the Harness. Be sure the wire is good at the Alt. Hook up. I think I lost quite a bit of Hair this week with Glow plug issues. I finally changed one M1008 to manual and by using "THE card" from one truck and installing it on my other, I got the glow plugs to work good on Both trucks. Good luck, Phil

Thanks Phil. I have had fun with GPs too in the past!
So far the driver's side alt seems to be working fine now. The pass side alt may be jealous tho. Last night the gen 2 light would glow faintly at warm idle. Any additional revs made them go away tho. I thought I heard one of the belts, so i checked them today and both seemed tight. They are new belts, so....?
I haven't cleaned the contacts on this alt and suspect that will be my next step. Anyone suggest a good contact cleaner?

 

[mangus580]

The gen2 light coming on slightly at a warm idle is somewhat common.

 

[Wolf.Dose]

Gen Problems

After 14 years of playing with a M1009 I learned about these problems.
Gen 1: The black one is the ground. Must be properly tied to the ground. And I mean realy MUST. The red one is B+ - Batterie plus 12 Volts, should read at least when running 12.8 V, normally allmost 15 V.
The broun cable with the round rubber cover is monitor plus to the monitoring resceptiat in the cab. This is not needed. The black smal cable beside the red thick one is also not needed; monitoring issue.
If Gen 2 control is slightly glowing, probably the fuseable linkage at the dash is not ok. This is difficult to see, for some red/orange cables are before the blue ones. Replace it by ordinary cables and add a 100 A fuse or 2 x 50 A fuses in the line.
Next general problem is: Generater life time is relatively short. Diods and electronic regulator to my experiance must be replaced allways at the same time. May be it is a design error or design overload. The same regulator is used in 57 A altinators, as well as the diode plate.....
I use the same configuration in my M715, due to the knowledge of the short points, it works fine for me.
Wolf

 

[BobM]

A 6.2 in your 715? I've gotta read about that!
Anyway, I looked at Ed's (pc3nmcb) '09 and saw the brown wire that SHOULD be on the ground wire on my '08. Ed's is in the right place and mine soon will be!