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Discussion Starter · #1 ·
Was driving my 69 Malibu today and noticed that the turn signal blinker weren't working. Got home and checked the fuse, checked power to the blinker can, all checked out. When I plugged in the can again and started the car the generator light came on and stayed on. I took my volt meter and checked voltage at the battery with the engine running and it registered 14.6 volts at idle. I would assume that the alternator is putting out enough voltage. Can't figure out why the generator light is staying lit with the engine is running. Another clue that I think is related is that when you step on the emergency brake and the brake light comes on it is only about half lit ,but at the same time the generator light gets brighter. All other lights seem to function normally including the parking lamps. I am convinced that the generator light,parking brake light and the turn signal are somehow related in this problem. Could I be experiencing a ground problem ? Could there be something defective in either the cancelling cam or the blinker can ? Does anyone know someplace on the web where I could download a simple schematic of how the turn signal blinkers and the generator light is typically wired ? Any suggestions ? Thanks.

Ted
 

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No offense DG but I don't think 14.6 is too high. Most charging systems put out +-14.5, go check another vehicle if you have one. An overvoltage would cause lights to be brighter. Since you have the opposite problem it sounds more like a bad connection. Probably not the main cables but wouldn't hurt to make sure they're clean and tight. Check the small positive lead connection, should go to a junction block on rad core support by battery. Check the small negative lead going to passenger front fender. Check the ground connections from harness to rad core support. One is behind the battery the other should be to the can of the voltage regulator. Several braided grounds from engine to firewall. Probably not the problem I don't even have those on mine. Good luck.
 

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All my vehicles read 14.3 with a digital VOM. There's an interesting voltage regulator test you can do on most older style SI type alternators that isn't well know. We used this test in the 70's and 80's. It may be old hat now but I've used it many times.

There's a small D shaped hole in the back of the alternator. Directly inside that hole is a small metalic tab on the internal voltage regulator. You can se the hole and tab in these pics http://www.madelectrical.com/electricaltech/delcoremy.shtml
By carefully inserting an allen wrench or small technicians screw driver (no more than a 1/4 inch, DON'T miss the tab), you momentarily ground that tab to the case. It disables the voltage regulator and allows the alternator to put out a full current charge. (that's actually what that tab is for) You should hear the engine idle change as the load is increased by the aternator. It you don't hear a change in idle or see a change in the output, voltage, it's a good indication the voltage regulator is bad.
 

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Herb,
14.3/14.5 could be my meter your meter my car your car. 14.2 to 14.6 is the typical recommended range. So I don't think his problem is related to the 14.6 output. It may be at the upper limit of what you want to run but shouldn't be causing a problem. Once all the connections are checked and tightened he should check the output again.
 

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The bottom left fuse in the fuse block, if I remember correctly, is the INST fuse. Check for a voltage drop across the fuse, clip to clip. Low voltage to the cluster will cause back feed through the GEN light. The INST fuse powers the GEN, OIL, TEMP and BRAKE lights and the fuel gauge. If the fuse clips are rusty the bad connection can cause a voltage drop across the fuse.
 

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Discussion Starter · #7 ·
Thanks to all that have tried to help me with this problem. Now I've got an update to the problem that I have. In the original message I told you that I was driving my Chevelle and noticed that the turn signals weren't working and when I got home and unplugged and reinstalled the blinker can the generator light can on and stayed on. Now here's the kicker ! Went to the autoparts store and got a new blinker can and installed it and turn signals started working, but only the front ones. Upon further investigation found out that I have tail lights, but no brake lights or turn signals to the rear lights. Pulled the connector apart in the trunk and other than the tail light wire the rest of the harness is dead. Checked out the fuse panel like Elree Colby suggested and every thing was a 12+ volts except the inst fuse, but it was close at 11.9 volts. Maybe the light switch reostat has something to do with it. Checked out the brake light switch, it has 12 volts going to it and I hooked the ohm meter to the switch and it seems to be working. There is a connector above the fuse panel that I think I will have to take the speedometer and gauges out to get at. I can barely touch it from under the dash. Am I on the right track or does anyone have any suggestions that I might have over looked ? Thanks for the responses so far. It's comforting to know the're are fellow car people out there willing to help in my hour of need.

Ted
 

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Leave the turn signal switch off (center position).
Press down on the brake and measure these wires on the large turn signal connector.
White
Green
Yellow.
Post back the results.
BTW, I have around 14.7 volts out of my alternator.
 

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Discussion Starter · #9 ·
John;
Found the problem with the turn signals and the brake lights. It was two seperate problems. The turn signal problem was caused by either a loose connector on the steering column or dirty contacts on the plug. I sprayed both ends with contact cleaner and the turn signals work front and back. The brake light problem seems to be either a worn switch or the assembly not seating all the way in the clip that holds it so it doesn't move when the brake pedal hits it. So those two peices of the puzzle are solved, but I still have a generator light that comes on when the car is started and stays on. Checked the voltage to the battery at idle and according to my gauge is putting out around 14.3 volts. I read somewhere that you can't just take the bulb out of the generator light because one wire is used as a ballast wire and you will damage the alternator. I have only had this car since June and still getting bugs out of it. Any suggestions from anyone as what to do next or where to look in regards to the generator light staying on ? Thanks.

Ted
 

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Discussion Starter · #12 ·
Just got the Chevelle up and running about a half an hour ago. The problem was that someone previous to me had tapped the tach light into the emergency brake light circuit. This light is part of the gen. light circuit. He had used a aftermarket add-a-connection and in the process had almost split the emergency brake light wire in half. I spliced the tach light wire into the dash lights and reconnected and soldered the emergency brake light wire. Put the dash back together and everything works as it should. While I had the dash out I took some contact cleaner and sprayed every connection I could get apart. Got all of them except the one above the fuse panel. Couldn't get the clips to release the plug and didn't want to pull on it as the only thing I could pull on was wires. Now everything seems to be working normally and seems like my tail lights are a little brighter than they used to be. Anyway I want to thank John M. and Peter's guide for helping me find the problem and saving me $400.00 that I would have had to fork out for a new harness. Thanks guys, I appreciate it.

Ted
 

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Check your E-Mail, sent you a schematic (in pdf format)
 
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