CUCV alternator symptoms, diagnosis and fix.

[rolcam]

ok I now got 29+ volts on red wire going to pos trem bd. but when i hook it up to pos. term bd it drops to 24?
coiuld it be:
suppressor form pos term bd. to neg board?
gen 2 relay?
gen 2 Diode?

 

[KevinPD]

OMFGROFL(and I DESPISE text crap...) I have never read sumtin as funny, mudman!!!! I can pic you dealing with this in frigid March...I was on my back under the '09 'round bout same time putting in my freshlyt rebuilt starter from a local el;ectrical shop here in Manch...NOT that the situation was funny, don't get me wrong..Your "colorful" and desciptive way of discussing it had me guffawing & belly laffin' THANKS FOR THE HUMOR IN A HOT JULY...

 

[sarge62]

if I ground the brown/red wire on the gen 2 relay the gen 2 light will come on. Does that mean I have a bad ground? Where should I look? The relay ground (black wire) is good. If I jump the pink/blk wire to the brown/red wire on the relay the light comes on.

 

[ARYankee]

I want to say THANKS to the folks that have contributed their expertise to this thread. I went to go start the 09 last Saturday and it tried real slow to turn over then click, click. My back battery was down to about 10 volts so I put it on charge while I surfed here for answers. That is when I came across this thread. I ended up having to use a different battery because the other wouldn't charge. I took the exciter plugs off both alternators and cleaned them. Then I hooked my batteries back up and proceeded with the voltage checks. Everything seems good now. I don't know if I solved the problem but now I have a better understanding of the alternators and some of the checks so I can keep an eye on it. Once again THANKS.

 

[MakersTeleMark]

Trying to diagnose a Gen 1 problem. A video of the behavior can be found at:

[media]http://www.youtube.com/watch?v=pbwTN34bPHI[/media]When starting up, both Gen lights come on and go off once running;
For about 5 minutes they stay off;
Volt meter on dash shows upper end of green/right on the red line;

It varies, but after some driving, usually around 5 minutes or so, the Gen 1 light starts flashing;
It will eventually stay on and the volt meter drops once it comes on;

It will randomly go out for periods of time during extended driving.

Here's what my DVM says:
Truck off voltage at front battery and red wire disconnected from Gen 1 is 12.6;
Key on voltage of brown wire is right around 12, but that's because the battery just fed the glow plugs;

Key on, unplugged alt and Gen 1 light is off on the dash.

When running, voltage at the front battery is all over the place from 13.6 to 14.4.

I've been trying to get a hold of CUCVElectrical for almost a month to order a rebuild kit. I've sent numerous e-mails to both of their accounts with no response. I've even PM'd 1st Sarge with no response. Anyone know how to get a hold of them?

I noticed the GEN 1 belt was a little loose so I tightened it. Also cleaned the contacts on the alternator plug. It's still happening.

Any thoughts?

 

[Barrman]

The video of your light going off and on along with your 13.6-14.4 range with the engine running. Say voltage regulator to me . However, did you check the big plug at the firewall, check the ground strap for GEN 1, all the connections on all 3 firewall connections areas plus your battery terminals?

Intermittent problems usually come down to a loose wire, bad ground or a regulator.

 

[richter1978]

My starter has burned out two switches (causing flexplate grinding), Gen 1 glows when radio/heater are on, volt meter is almost in red and front battery leaks. After reading this thread I am going to do the checks of the alts and batteries and clean contacts. Is there anything else I should look at, would alt problems cause the starter to suffer.

 

[richter1978]

Not knowing really anything about the electrical, this has been most informative.

 

[kcbbqguru]

I am only getting 12.45 volts volts at the battery and the alternator after starting my truck? where else should I check? I am checking the alternator at the big red wire and grounding the neg side of my volt meter, thanks

 

[Barrman]

Check at the positive and negative terminal for the battery charged by the alternator you are checking. Drivers side alternator does the front battery and passenger side alternator does the rear battery.

 

[kcbbqguru]

12.45 front battery and 14.4 on back battery

 

[Vhyle]

I'm rebuilding one of my alternators with the 27si kit from ASP Wholesale. I'm unsure where the new capacitor (pn 46-1106) is installed in this kit. The old capacitor spans from the bottom to the top of the alternator, whereas this new one looks like it only fits from the top to the bottom of the rectifier. This diagram (http://www.aspwholesale.com/images/exp_views/DR-27SI_100.jpg) shows the capacitor in the diagram but no specific location. Is it an extra component?

EDIT: Nevermind, I figured it out.

 

[kcbbqguru]

After Reading every post on the forum about gen 1, and collecting all the information about Brown wires, replays etc.... I thought what the heck, I should check the belt?? No it couldn't be something that simple, but sure enough, there was too much play, ran up and got the correct size belt and wamo..... 14.4 volts on gen 1, So to everyone with a gen problem, CHECK THE BELTS FIRST!! thanks

 

[tankie88]

Right,i've just rebuilt my drivers side alt.Put it back in the truck.Turned on ign.Gen 1 light dim.Start up and gen 2 goes out but gen 1 still stays dim.Idea's anyone?????

 

[cpf240]

Right,i've just rebuilt my drivers side alt.Put it back in the truck.Turned on ign.Gen 1 light dim.Start up and gen 2 goes out but gen 1 still stays dim.Idea's anyone?????

Have you driven it? Did you bump the throttle to bring it off idle to get GEN 1 going? Mine always takes a good throttle bump, or driving, to get the GEN 1 & 2 lights to go off. I think it is even mentioned in the TMs.

 

[tankie88]

Yes,done all that.The next thing was a bit of logic.......it all worked before i took it all to bits.So,took it all to bits again and start putting back the old parts one at a time.The 1st thing to change back was the voltage regulator.Low and behold it all worked when i put it back together.Now what are the chances of a new voltage regulator being u/s??????

 

[cpf240]

I'm glad you found the problem! Faulty new parts are not all that unusual, especially if they are made in certain areas of the world. The problem is remembering that and not assuming the new part(s) "must be good".

 

[Gottlos]

Subscribed. I've got some testing to do ASAP! My problem is the reverse of most of the posts here. Both gen lights come on with the key and go out when running. But my gen lights flicker very dimly at higher RPM levels with no real pattern and when I hit a bump in the road the GEN 2 light flashes brightly then goes out. The belts are tight, the wires look good, alternators were rebuilt awhile ago, batteries are questionable. The only change recently has been a replacement inst. cluster.

 

[Walrus]

As an FNG to the 09 I have been working a driver’s sidealternator issue. After reading thispost I did the red and brown wire test and had the alternator rebuilt. After the rebuild the voltage meter wasreading in the green and a week or so later now is back at the yellow greenline and will drop to the yellow while driving. I used an ohms meter to get the output from the driver’s side alternatorat idle I get 12.3 and 11.9 at the front battery. With slight accelerator I get 13.1 from thealternator and 12.3 at the battery. Theshop that did the work said everything is working as it should but I do not getthe warm and fuzzy. Is this normal for the 09 or do I need torebuild the alternator again?????

 

[Warthog]

Walrus, you need to add your state to your user id. It is a site requirement.

Check your ground wire on GEN1. The one going from the negative terminal of the alternator to the engine. Alot of times the connector on the engine is bad/dirty.

A properly functioning alternator should put out ~14.5v. 13.1v is too low.

Also some of the parts that are on the market now are NOT very good. They don't last. I would take it back to the rebuilder and have them show you that it is putting out 14.5v