SERIOUSLY PUZZLING ELECTRICAL PROBLEM!

[Zambezitiger]

Hi everyone.

Firstly let me detail that my car is a 2000 Chevy Blazer LS with only 53,000km's on the closk and is in immaculate condition.
Problem is as follows:
My battery has started to discharge as displayed on the volt meter on the dash and the red battery light has come on at the same time. On getting a sparky to go over the vehicle they detected a short on one of the light circuits which they closed, cleaned the brushes on the alternator and she seemed to work fine for a week. Then the same fault occurred again, the battery light came on and the volt meter showed that slowly but surely the battery was again discharging.
The car is back with my mechanic, a good friend who is an accomplished mechanic and sparky (old school), and they have since removed the alternator and diagnosed that the regulator and rectifier on the regulator are at fault. However, as we live in Zimbabwe we don't have any local Chev dealers in proximity of around 1500km's, so cannot simply go out and buy another rectifier / regulator, if in fact this is the cause of the problem.

Can anyone tell me if they have had any similar experiences such as mine and if so, how they solved them or what best advice they may have?

I have just bought this vehicle and have only driven it a few hundred Km's so am a little concerned to say the least at the problem at hand...

I would be immensely grateful for any assistance anyone could render me ASAP!

Cheers.

Sean.

[ex IROC Crew]

I'll take a shot at helping you, but some additional information would be helpful. Mileage of the vehicle, mileage at which the plugs were changed, and any other service work that has been preformed would be of interest. Also, when you changed the plugs, did you use the manufacturer's recommended plug or an aftermarket part? When the plugs were changed, did you change the plug wires, the rotor, and/or the cap? Was the plug change the first time they were replaced? Can you be more specific about the degradation in preformance? How much has the fuel economy changed?

[Zambezitiger]

Thanks for your time mate.

Ok, mileage is 53,000Km's.
I have just purchased this car so have performed no servicing on it whatsoever, as is running very smoothly. No problems at all mechanically I must stress.
It is just discharging the battery for some strange reason? No change in fuel economy also. We have merely cleaned the brushes on the alternator as suspected they may have had some corrosion but wasn't expecting this considering car has only done 53,000kms?
There is no change in actual handling performance, runs like a dream when was running!

Could the rectifier or regulator be at fault here and if so, what would cause this more importantly at such a low mileage?

[BBlazzerr]

Hi Sean,
Electrical problems can be a real pain to find sometimes. Being your engine starts and runs good means your battery is good and is actually supplying all the electrical power to run the engine. Your problem is getting electrical power from the charging system to keep your battery charged. Your local old school mechanic is doing the right proceedure to find your problem. I see your main problem at this time is acquiring the needed parts and spending the least money for them. What I have done in the past is to buy an alternater rebuild kit which is half the price of a rebuilt alternator. They normally have the diodes,brushes, regulator and new bearings and other parts included in them needed to make your alternator good as new.. A quick look online and I found this supplier of rebuilt kits for GM vehicles. If your import customs fees and postal service aren't a problem this link below should help you. Also the kits don't weigh much. Hmm, also check that the grooves on the surface that the brushes run on are not filled with dust from the brushes wearing down. I'm near Disneyland in California. I hope this is helpful for you.
Good luck,
Gunnar http://alternatorkit.com/

[Zambezitiger]

Hi Gunnar

Thanks very much for your time in replying, very much appreciated.
OK, I will get onto this site and see what costs are involved, as shipping will just be through DHL etc. so should get here....I Hope!
Had a chat with my mechanic today and he seems confident he will win with what he is trying out now so am holding thumbs. Would be nice more importantly to know what caused the initial drain though, seeing as the mileage is still so low? On opening up the alternator everything is shiny brand new....only one brush was sticking which we cleaned but as for the rest of it, in spanking condition. In fact all wires and engine parts look straight out the box, hence my concern.

Anyway will keep you all posted once a solution found so may be of some assistance to the next poor soul who goes through the headaches I am going through...!

Cheers for now

Sean.

[BBlazzerr]

so am holding thumbs.
Greetings Sean,
Over here we say , "Twiddling Thumbs", when we are stuck waiting for something to happen.

The low kilometers on your vehicle is a good thing but has nothing to do with your charging problem nor does how shining and new the altenator internal
parts look. Electrical problems can be most frustrating to isolate being it all just lays there not working and there is so much to check and getting at some
areas can be most difficult. I have learned to check all of the simple things first before in frustration you start tearing the instrument panel out and then
finding a minor fault like a fuse that LOOKS good but isn't. More than likely when you get the needed replacment parts you will be back on the road again
and moving on to more fun or industrious pursuits.
I did have one thought that I would run by your old school mechanic. Being that your system was charging after repairing the light circut short then finding
the brush stuck in the altenator it could be that the brush is stuck again and has worn away from the communtator as it did before. If the housing around the
brush is warped or the brush doesn't fit it right , (Was the original flaw that made the brush stick eliminated? ) you might be back right where you started.
Also I would question why if there was a short a fuse did not blow? It dosen't make sense that a light circut short didn't blow a fuse. Maybe it did and you
didn't mention it and the no charging fault is not connected with the light circut problem.
I'll leave with a couple of electrical problems I've had experience with. Went to start my wifes Blazer one morning and the battery was dead. Got out my
charger which is self regulating and left it on overnight to charge the battery. Checked it out the next morning and the charger was showing an 8 amp draw
and if it charged the battery it should be showing about an 1/2 amp draw! My 1st thought was that I was off to purchase a new battery then thought I would
do a simple test to see if a low draw short was the problem. I disconnected the ground cable on the battery then tapped it back on the battery terminal and
got a very large spark showing a current draw somewhere in the vehicle. I lucked out when I was looking in side the vehcle wondering where to start and
noticed that the 5 interior lights were on. My wife had left the rear hatch window ajar! 5 lights equaled 8 amp draw. DUH! Lucked out this time.
Left front and rear turn signal lamps, tail light, stop light all on and going up and down in intenscity but no function. Many hours later found the on one of
the stoplight/ taillight bulb combos that one filament melted down in to the other filament! Duh!
Far thee well,
Gunnar

[Zambezitiger]

Hi Gunnar

Thanks again for your advice here, will print off and take around to me old mechanic, as he is a bit primitive and doesn't believe in modern technology such as e-mail and internet! Hell of a good with a set of tools though....

I cant believe how many minor issues can cause electrical faults in these cars (internal lights, blown bulbs etc?) Anyway as you said, am just wanting to eradicate this problem so I can start to enjoy my blazer and making good memories with her...

Will keep you posted mate.

Thanks again.

Sean.

[4x4x4doors]

One other frequent source of electrical issues is a short that may develop in the vicinity of the trailer wiring.

Even if you don't have a trailer light plug wired in, the wires to have one are often there. They will be under the rear and perhaps tied to the rearmost cross frame member.

[ex IROC Crew]

Sorry for my previous post. It was targeted for a question by another person. Must have been a case of brain fade.

One thing you might want to check is a large wiring harness on the left side of the engine. There is a pedestal bracket that supports the top radiator hose, and it is positioned near the harness. There have been some instances where a pointed corner of the bracket has pierced the wiring harness causing all sorts of wierd electrical problems. When you examine the pedestal bracket, the corner near the harness should be evident.