IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: SuperSix on October 13 2008, 07:19:01 PM
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(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
-
(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
Maybe I am missing something, but you will get no alternator output with the ignition off. You should still read battery voltage at the alternator though. I am not sure but you may be looking for a fusible link, not a fuse.
-
(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
There is no fuse in the circuit. With the key on, voltage comes thru the ignition switch to the bulb in the dash and onward to the alternator via the small brown wire that plugs into the alternator.
If the bulb does not light when the key is turned to ON, the alternator cannot charge.
Sometimes the bulb is bad, more often, it has just decided to quit making connection with the pc "board" behind the dash panel. Sometimes wiggling stuff around will make it start working again if the bulb was good and not burned out.
This is a common problem with these cars. Now, if the bulb cannot be convinced to light...there are a couple of potential fixes, or so.
First, however, I would unplug the the brown wire from the alternator and ground it to the engine...then turn the key on...if the light comes on, then you know you have an alternator problem, if it still does not come on, then you know you have a problem in the circuit...most commonly the bulb or its connection.
Okay, one cannot simply supply a voltage from an ignition switch source to the alternator as the bulb serves as a resistor to drop the voltage a bit. Leaving out this resistance will burn out the diodes in the alternator in short order.
One can take a 475 ohm resistor and insert it in a wire coming from the ignition switch and going to the alternator to replace the brown wire circuit.
One can buy a similar plug and play device from John Spina at Casper's...think it connects between the wastegate voltage feed wire and the alternator.
One can replace the 475 ohm resistor with a dash lite bulb and similarly run it from an ignition switch source...and it will come on and off just like the one in the dash did.
And, of course, one can mess with the one in the dash until it works.... :D
-
(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
Maybe I am missing something, but you will get no alternator output with the ignition off. You should still read battery voltage at the alternator though. I am not sure but you may be looking for a fusible link, not a fuse.
Basically, the "exciter" wire isn't delivering a signal for the alternator to put out.
-
(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
There is no fuse in the circuit.
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don't think the alternator circuit is connected to the turnsignal bulb burning slightly....th at does sound like an oddball problem.
Electrical problems are not my favorite either...:)
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don't think the alternator circuit is connected to the turnsignal bulb burning slightly....th at does sound like an oddball problem.
Electrical problems are not my favorite either...:)
It looks like I may have to pull the instrument panel out and check/clean all contacts, and grounds. That's the only explanation i can think of for the odd turn signal bulb activity.
Dammit Wood - I only gave you access to the board to rip in Zap and help me with electrical issues, and you are failing on 1/2 of that commitment.
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I will work harder on ripping Zip. He is smarter than me, but, I do sleep less than he does! :(
At least I am four inches taller than Toadboy and weigh 25 lbs less-being bald has its benefits.
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Uh, Zap gave me the wrong info to post, too!
You could check the gages fuse while you are on your knees praying to the electrical gods.
18 terminal connector on the dash pc. Two black wires are grounds. Brown wire on connector is the feed from the dash to the alternator.
Look at page 8A-82-12
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(Kinda like my ex-wife, just a LOT less expensive)
Here's the deal.
Voltmeter indicates no alternator output. VOLT bulb doesn't light when IGN on, engine off. Replaced bulb - no change.
What and where is the fuse for this circuit? According to the service manual, and what I have done, i need to be looking for an open wire between the IGN switch and the ALT. Is this common?
Thanks
Marko
There is no fuse in the circuit. With the key on, voltage comes thru the ignition switch to the bulb in the dash and onward to the alternator via the small brown wire that plugs into the alternator.
If the bulb does not light when the key is turned to ON, the alternator cannot charge.
Sometimes the bulb is bad, more often, it has just decided to quit making connection with the pc "board" behind the dash panel. Sometimes wiggling stuff around will make it start working again if the bulb was good and not burned out.
This is a common problem with these cars. Now, if the bulb cannot be convinced to light...there are a couple of potential fixes, or so.
First, however, I would unplug the the brown wire from the alternator and ground it to the engine...then turn the key on...if the light comes on, then you know you have an alternator problem, if it still does not come on, then you know you have a problem in the circuit...most commonly the bulb or its connection.
Okay, one cannot simply supply a voltage from an ignition switch source to the alternator as the bulb serves as a resistor to drop the voltage a bit. Leaving out this resistance will burn out the diodes in the alternator in short order.
One can take a 475 ohm resistor and insert it in a wire coming from the ignition switch and going to the alternator to replace the brown wire circuit.
One can buy a similar plug and play device from John Spina at Casper's...think it connects between the wastegate voltage feed wire and the alternator.
One can replace the 475 ohm resistor with a dash lite bulb and similarly run it from an ignition switch source...and it will come on and off just like the one in the dash did.
And, of course, one can mess with the one in the dash until it works.... :D
Of course, Steve is right AGAIN.. :068:
After reading the service manual for a few hours last night, I decided to tackle this issue.
I took out the cluster, and first wanted to make sure that the voltage to the VOLT light > alternator circuit that comes grome the GAGES fuse was there. Found the 2 power wires, PNK/BLK. I turned the key on, voltage at both. I found the brown alternator wire tab connector, checked for continuity with the other end under the hood, it was good. Checked that wire for a short to ground, nothing. So, all is checking out good. This now means that the problem is in the cluster itself, not the wiring.
I removed the cluster. took it all apart, down to nothing but the housing and the flexible circuit sheet. First I took a good old #2 pencil, promptly broke it in half, and chucked it into my DeWalt cordless drill. I used the eraser end to buff the copper contacts on the circuit "board". It didn't seem to be making it as shiny as I wanted it, as fast as I wanted it to, so I switched to Scotch-brite pads. I cut a small square off and used that to lightly buff all of the contacts to a shiny copper finish. Of course, I polished up the contacts that take the signals from the bulk head, and the bulkhead wiring connector itself.
I checked, cleaned and refurbished each and every light bulb and socket too. I had 2 bad bulbs, and I used the new bulbs for the turn signal indicators, I figured those get the most use overall. I put them back, one at a time, using the Low Fuel socket for testing. Once they passed there, I put them in the sockets, and tested them again.
First, I plugged in just the cluster housing and held it in with my hand and tested the lights. Parking lights - check. IGN on, no volt light. :013: Then I remember I hadn't reconnected it with the alternator. Doh. So I reconnected it. Pressed the panel back in - VOLT light was on! <happy dance> I learned that when you turn the ignition between ON and START and the OIL/VOLT/BRAKE lights comes on is by design and called "Bulb Check". Used that - all 3 were blazing gloriously. Finally, after more than 3 years, my charging system works correctly..
It's amazing what you can do when you just stop whining and put some effort into it.
Next up is the dome-light-stuck-on issue.
:icon_super: :icon_super:
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LOL..glad someone is making progress. Lately, each step of progress adds ten more things that need to be fixed before any progress could be noted
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Took the wife and stepson for a ride today to my parent's house - they love the car. :)
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A million years ago when we cleaned contacts on teletype machines
we used something like this- a fiberglass brush- works wonders
http://www.eraser.com/catalog.cgi?mode=details&product_id=1225 (http://www.eraser.com/catalog.cgi?mode=details&product_id=1225)
(http://www.eraser.com/images/nc/1614.jpg) (http://www.eraser.com/images/nc/1614.jpg)
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The contacts were int he condition I expected them to be in. 25 years old, and in a t-top car that needs new seals, there's surface rust on many surfaces. The copper didn't look that much better.