Trailblazer 302D low AC voltage

[tjwelds]

Hi folks, I've got a problem with my TB and was hoping the "collective" could help. I've been following the forum for a while (just never joined) so I scoured several older posts but nothing that matched my situation exactly. Anyhow, about two weeks ago I noticed the 120v outlet seemed a bit weak so I went through the usual routine. Fuel filters, air filter, oil, check and adjust run/idle speed (3750 no load) . No change. Ordered and installed new brushes and cleaned slip rings. No change. Checked wiring and connections. Found a broken spade connector on a (physically) large 200 ohm resistor, located above the fuel tank and beside the PC1 board. Replaced the spade connector and checked resistance (out of circuit), 200 ohms. No noticeable change. Btw, my meter showed 110v and 220v at the outlets. I was unable to check the freq because my meter is very basic. I went ahead and ordered a good fluke and had it shipped 2 day priority..... a week ago. (yup, that's my luck). So it should be here between Monday and August. It still welds strong on DC, but feels weak when welding on AC. I fear that a new PC1 board will have to be ordered, but it seems that I read a post here some time back about needing to replace other components at the same time as the board. A rectifier of sorts if memory serves me correctly ( and it usually doesn't, haha). Anyhow, advice on the matter would be greatly appreciated. My machine is a 2006 Trailblazer 302D ser# LG054799 with almost 3000 hrs. Thanks again, T.J.

[Kpack]

Man I hope the can get you fixed up without the board sounds like a nice machine can a company like flightsystems check these boards I hear they do a good job for a good price

[tjwelds]

So i got my new Fluke in today and here's what I found. 115v and 62.8Hz @3750rpm/no load. Also, I plugged in my plasma cutter (spectrum 625) and watched at the plug under a load and the volts dropped quickly to about 160 when the plasma faulted. Any ideas? And I have run that plasma cutter off of my machine before and that never happened so it is unusual. Thanks.

[tjwelds]

Man I hope the can get you fixed up without the board sounds like a nice machine can a company like flightsystems check these boards I hear they do a good job for a good price

Thanks Kpack, me too. It's a great machine and I really enjoy it. If I can't get it figured out then I will look into someone like them. Thanks again.

[Kpack]

I don't know much about them but does the unit have brushes and slip rings I know my old stuff does might check the length of the brushes

[tjwelds]

Yup, I cleaned the rings and replaced the brushes. That was one of my first steps.

[raferguson]

Generator testing

When I am checking out generators, I like to apply different loads, then listen, watch and measure what happens. There is a nifty box called a kill-a-watt for 110V, will measure voltage, amperage, Volt-amp, wattage, total wattage, frequency, and maybe one or two other things.

Electric space heaters and construction lights are simple resistor loads. Motors involve surge current at start up, so a very different load. But it is not trivial to measure the surge current. I have to think that a plasma cutter is also a complex load.

It is good to take baseline measurements and write down the result. Then you can check the result later and see if whatever you did improved things or made it worse.

Good luck,
Richard

[Kpack]

Did you use a commuter stone to clean the slip rings and then run it on there again to seat the brushes good I believe you run it behind the brushes so the dust goes under them .

[tjwelds]

When I am checking out generators, I like to apply different loads, then listen, watch and measure what happens. There is a nifty box called a kill-a-watt for 110V, will measure voltage, amperage, Volt-amp, wattage, total wattage, frequency, and maybe one or two other things.

Electric space heaters and construction lights are simple resistor loads. Motors involve surge current at start up, so a very different load. But it is not trivial to measure the surge current. I have to think that a plasma cutter is also a complex load.

It is good to take baseline measurements and write down the result. Then you can check the result later and see if whatever you did improved things or made it worse.

Good luck,
Richard

I've seen those before but never thought of using it for my machine. That's great info, thanks.

[tjwelds]

Did you use a commuter stone to clean the slip rings and then run it on there again to seat the brushes good I believe you run it behind the brushes so the dust goes under them .

Yup, clean and seated. But keep coming with the ideas. I believe there's only two ways to learn, your mistakes or someone else's mistakes. I'm hoping for someone else's, haha. Thanks Kpack.

[Kpack]

I'm trying to help the no load hz looks good rpm good. Is there a way to to check fuel delivery when you load it . I mess with a few generators and sometimes under a full load I have to open the main jet a little bit even though its fine with no load. But I don't know diesels to good but I guess it could be fuel delivery. Is there a good way to clean the injectors or any kind of setting on the pump that you know how to do without causing problems. Maybe some linkage hanging when it tries to load and ask for fuel. I'm just trying to think of the simple stuff . When you load it try to watch your linkage or move it by hand see how it sounds and feels.

[tjwelds]

Would it be fairly accurate to load it up and watch the rpms? And does the throttle solenoid have two set positions or will it compensate slightly like cruise control? I will check tomorrow after work and let you know what it's doing. Thanks.

[Kpack]

Just be carful don't do anything rash maybe cruiser or somebody may get in .