TC30 wiring/alternator questions

[Thow]

Afternoon all. Just bought a 2004 TC30 in abused condition - but it started and runs. Able to finish some work I wanted to get down and am now working on getting it back to good condition. Started on the wiring and have the schematic which of course didn't match what had been done to the wiring. After ohming and testing the wires, think I got most back to the way it should. The questions: first, the hot wire going from battery to the 3 fuse box had been cut and connected directly to the fuel solenoid. I identified the correct fuel solenoid wire but is there some other issue this may have been correcting before I change? Second, the alternator had a ground wire going to the stud on the back and the red wire going to the sole tab. The other two went to the two tabs with the connector. Is that correct? I replaced the alternator and researched a little on the wiring hookup and most of the research said the ground is created by being bolted to the engine and that the stud should get the red wire from the battery and the tab the red wire from the ignition. The schematic shows a ground wire to the back. A pic of the back of an alternator properly wired would be great.

Looking forward to this forum and all the feedback to get this back in shape.

 

[nyone]

It's a 3 wire alternator? If so typically one larger wire is 12v charging circuit,one is 12v keyed and ground. You may also have a tach wire if it doesn't have a mechanical one.

 

[Thow]

It's a 3 wire alternator? If so typically one larger wire is 12v charging circuit,one is 12v keyed and ground. You may also have a tach wire if it doesn't have a mechanical one.

Well, what I've googled says it's a 3 wire but there were four wires hooked up to the old alternator. 3 were probably 16 gauge - including the ground - and the larger wire is probably 10 gauge. As it was setup, I think there was only one "hot" wire to it. Besides the black ground, believe one of the other two smaller ones goes to the instrument panel as some kind of indicator and the other goes to the seat safety switch...

 

[nyone]

Time to get out the wire disgram

 

[Thow]

Time to get out the wire disgram

Funny thing is that's why I requested a pic of the back of a functioning one. The wire diagram shows 4 wires to the back but everything I read online points to three and no ground wire. Kind of corn-fusing for a car guy.....

 

[jigs_n_fixtures]

Funny thing is that's why I requested a pic of the back of a functioning one. The wire diagram shows 4 wires to the back but everything I read online points to three and no ground wire. Kind of corn-fusing for a car guy.....

Is it a diesel? Diesels frequently have a wire from the alternator to the tachometer. Things with spark plugs use a signal from a coil energizing a spark plug to count the revolutions. On a diesel you don't have the coil and spark plug, so they have wire to the tachometer and use the rpm of the alternator as the signal.

More modern setups use hall effect sensors on the flywheel, torsion dampener, or the cam drive system.

 

[Thow]

It is a diesel. One of the two small wires is probably the tach. Hard to tell on the schematic but it does go to instrument panel. Still wondering if a ground wire is on the back and where it goes

 

[toot77]

It's not the tach. The tach is mechanical, i.e. cable operated. The wire going to the dash is for the battery charge indicator light. Attached are a couple pages from a 1520 service manual showing some alternator electrical detail. I believe a TC 30 is the same so should work with your TC 30 general wiring diagram.

 

[Thow]

It's not the tach. The tach is mechanical, i.e. cable operated. The wire going to the dash is for the battery charge indicator light. Attached are a couple pages from a 1520 service manual showing some alternator electrical detail. I believe a TC 30 is the same so should work with your TC 30 general wiring diagram.

Thanks. I'll see what I can do with these. Also, I knew the tach was mechanical as I have disconnected it to get the panel off, had a brain timeout on that one. The other small wire ends up in the seat safety switch timer.