What is making that squeal at start-up?

[edpdx]

For a while now every time I start cold (in the morning) my M1009 something squeals if I give her any pedal. Checked my belts, all new and correct/tight. When I let her warm up for 4 o5 minutes, it goes away. Anyone have an idea what does this?

 

[Digger09]

Possibly one of your alternators. I had one that did the same thing. Once it ran a few minutes it stopped.

 

[Gottlos]

Mine does the same thing. Try some belt dressing before you start it up. Quieted mine down.

 

[phil2968]

Belts need tightening. At least one does.

 

[tbearatkin]

Its the draw on your alternator because your Glow Plugs are still on. Once your volt meter returns to the green your plugs will be off and your squeal will go away. My belts are tight and it still does this until the GP are off. Might be my alt is not the 100 amp stock but the 78 amp Cadillac alt. I have not checked it.

 

[edpdx]

tbear: I will check your theory, but I don't get why it would squeal. It's not the bearing but rather the belt, right?

 

[jwaller]

It's the high amp draw at startup with the gp's on and the battery already drawn down from gp prestart and cranking. You are asking the alt for its max output and the belts just slip.

Tighten the belts.

 

[tbearatkin]

Yes its the belt. You can try making it tighter. Do not think I can get mine any tighter. I also have done away with the resistor that dropped the 24v down to 12V for the Glow plug. So now instead of a even draw from both alternators it is drawing all those amps from one. As I said mine only will do it if I accelerate while the GP's are still on. So I do not drive off until my GP go off. No squeal. Next PM check will also see what size alternator I have as well. It only takes about4 5-60 seconds for the GP's to cycle off once it is running.

 

[Ridgeback]

Yeah, mine does it as well now - squeals like a banshee for a min or two then pipes down. It squeals worse on cold days and on almost every start now. I'm going to tighten the belts and hit them with some of that fan belt dressing...see if that make it pipe down a bit!

 

[rsh4364]

My 1009 did the same thing,noticed pwr steering belt was to loose so alt.belt was doing all the work,switched both out and all better.

 

[rsh4364]

Yes its the belt. You can try making it tighter. Do not think I can get mine any tighter. I also have done away with the resistor that dropped the 24v down to 12V for the Glow plug. So now instead of a even draw from both alternators it is drawing all those amps from one. As I said mine only will do it if I accelerate while the GP's are still on. So I do not drive off until my GP go off. No squeal. Next PM check will also see what size alternator I have as well. It only takes about4 5-60 seconds for the GP's to cycle off once it is running.

Im getting ready to do the resistor bypass and wondering if it might be better to pull glow plug power from neg. term on rear batt?

 

[edpdx]

I was skeptical, but after three starts, I see the light.

Thanks for sharing.

 

[doghead]

That is where it comes from already(the 12v terminal block).

 

[tbearatkin]

Im getting ready to do the resistor bypass and wondering if it might be better to pull glow plug power from neg. term on rear batt?

All that will do is take the 12 volts off the front battery. Mine is hooked up at that spot. Any 12volt connection will be for the front battery. Mine has been on the front battery since I got my CUCV and this is the only issue and I can deal with a little squeal if I take off too soon it does get everybody's attention

 

[rsh4364]

Thanks for the input,so I should just pull pwr.from the right side of 12v.terminal block and save $ on copper.

 

[wtn6auva]

My M1009 squealed like crazy at start up but the last time I started it, the squealing continued longer than normal and then it abrupty stopped and my voltage gauge went to 12 indicating that my Alt #1 isn't charging. Does this sound like the alternator finally went out or could it be a belt problem? I have the belt as tight as I can get it.

 

[Barrman]

If your volt meter shows 12, then it is an add on. The stock volt meter with just a single alternator working will be just on the yellow side of the yellow/green line with the engine running and the other alternator working fine.

As already posted, anybody that has done the resistor bypass is drawing all the glow plug power from just the front battery. That battery handles half of the starting work and then has to do all of the after glow by itself. Along wtih the lights, wipers and anything else 12 volt in the truck. The after glow period goes on for a good while in really cold weather. That is a lot of strain on that alternator and belt. Even with the belt tight, with the hood up, all of my alternator 1's will make a whine the first minute or two. They are working very hard.

Loosen the drivers side alternator belt. Tighten the power steering pump and then do the alternator. Doing the alternator first will never give you a tight power steering belt.

The alternator that stopped making noise and appears to have stopped making voltage probably is in need of a rebuild. However, it could just be the plastic plug finally gummed up enough to not conduct electricity. Only following the steps listed out in the -20 troubleshooting section can answer for you though. We can't through our computer.

 

[Drock]

While I was doing my coolant crossover swap I spilled some coolant down into the passenger side alt. It didn't "squeal" but it did have ah hard time charging when first started in the morning. The Gen light would stay on and the gauge would read low until the truck would warm up. It took changing to a shorter belt and spraying half ah can of electrical parts cleaner into the alt to fix the problem. Maybe your alt's are just funky inside and could use ah good cleaning. Here's the stuff I used....http://shop.advanceautoparts.com/p/...069-P?searchTerm=crc+electrical+parts+cleaner

 

[cucvrus]

I equate this to smoking the tires on the tires on the truck every time you start it. They will eventually wear out. As the belt is squealing it is getting hot as are the pulleys on the alternators. Then the pulleys get polished and you know how metal gets once it has been heated up and left to cool and exposed to moist ore. Rust will form almost immediately. And after a few squealing start ups the belt sinks deeper into the pulley and the belt gets looser and thinner. I would suggest a few things. I have done it. I replaced my stamped steel pulleys with solid cast pulleys and they do not heat up as fast and they do not rust in the grooves. I have some belt issues occasionally. But usually after slaving another truck for a long time or plowing snow. But seldom does it last over a few seconds. I have the GP system all OEM and mine cycle and charge off of both alternators after start up. That helps also. Both working is better then 1. My opinion only to help out. I know it works and I can provide pictures of the solid pulleys if you are interested. The pulleys may be aluminum. I never gave it any thought what they were made of. I just ask the man at the alternator shop to put some thing else on the truck because I was tired of smoking the belts .

 

[tankie88]

Mine was also squealing.I put a new altenator pulley on and that stopped that.The pulley V on mine was worn out.