A different 'choke light' question for a change...
#1
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
A different 'choke light' question for a change...
OK. So, my choke light starts to shine and that wonderful buzzing starts to come on, but only at certain RPMs. It does it at idle sometimes (probably around 500 or so), and then again while driving (maybe 1500). I can understand the light coming on if the RPMs were too low at idle, but why while driving and at only a certain RPM? My alternator seems to be charging the battery ok. I'm not sure how old it is though. All the fuses are still good. This has been going on for a long time, too long to remember if it's a result of an unfriendly mod. The carb could use a rebuild, but the only thing that's been done to the carb is a new choke thermostat. All my mods are in the sig, and I don't think they could've had something to do with it. Any thoughts?
#2
Supreme Member
Join Date: Nov 1999
Location: NE
Posts: 2,860
Likes: 0
Received 2 Likes
on
2 Posts
Car: 82 camaro SC
Engine: 350
Transmission: 700r4
Test the alternator, it might be on it's way out(brushes nearly worn out for example). What you describe is why my 82 did for a long time, then the lights would flicker at a constant rate. The light flicker was annoying so I rebuilt the alternator. Works fine now. Also, the whole time it was acting up the battery would stay charged.
#3
Supreme Member
Join Date: Jan 2001
Location: Rock Hill, SC
Posts: 1,411
Likes: 0
Received 3 Likes
on
3 Posts
Car: 1999 Pontiac T/A Firehawk
Engine: ***'s Engine
Transmission: T56
The buzzing is actually the choke relay. In rare cases, the relay will go bad, and doesn't indicate a problem with the alternator.
99 times out 100 it's the alternator. The choke coil itself actually has NOTHING to with it... all it does is provide a path to ground.
99 times out 100 it's the alternator. The choke coil itself actually has NOTHING to with it... all it does is provide a path to ground.
#4
Member
Join Date: May 2003
Location: SillyCon Valley, CA
Posts: 264
Likes: 0
Received 1 Like
on
1 Post
Car: 83 Z-28 (Original owner)
Engine: 305 CC-carb
Transmission: Richmond 6-speed, Rear:3.73
Sounds like the Alt is not putting out a clean DC voltage. How old are the alt brushes? They are easy and cheap to replace. Before worn brushes completly fail, the start to "bounce" at certian RPM's.
#5
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
i was able to test my alternator yesterday, and it's putting out the propper voltage. even at the rpms that the buzz starts to go off. so, i guess the problem is with my relay then? how might i fix that? i've read through several searches that the relay is (maybe the green wire) attached to the aldl. but that doesn't really tell me what/where it is? any ideas?
#6
Supreme Member
Join Date: Jul 1999
Location: Loveland, OH, US
Posts: 18,457
Likes: 0
Received 15 Likes
on
15 Posts
Car: 4
Engine: 6
Transmission: 5
The buzzing is caused by one failed diode in the diode trio in the alternator. What ends up happening, is that the alternator is working 2/3 of the time which is enough to keep the batt charged and to make it appear to test good, but not working 1/3 of the time. That condition overstresses the rest of the alt and will shorten its life, besides just annoying the hell out of the driver.
Either replace the diode trio if the rest of the alt is fairly new, or just get a new alt if it's got lots of miles on it.
Either replace the diode trio if the rest of the alt is fairly new, or just get a new alt if it's got lots of miles on it.
#7
Member
Join Date: May 2003
Location: North Carolina
Posts: 283
Likes: 0
Received 0 Likes
on
0 Posts
Car: 83 z28
Engine: L69
Transmission: BW t-5
Yes, listen to the guys, it sounds like the alternator, and it usually is, and these guys know a LOT more than me. I would replace the things RB was talking about or get a new alternator.
Trending Topics
#8
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Hey RB. I read your post on Choke light still on, Alternator seems fine, Now What? Very informative. I'm gonna check that out. Thanks man. I appreciate it.
#9
Supreme Member
Join Date: Sep 1999
Location: Oakville, Ct
Posts: 1,383
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1991Firebird T/A
Engine: 350
Transmission: Modified Viper t-56
Axle/Gears: dana 44, 3.55
replace it.... its definately the diode trio- i had the same thing happen to me in my 86, and the alt tested fine... i picked up a new one, and put it in, and whamo, it problem solved.
#10
Supreme Member
Join Date: Feb 2000
Location: Johnstown, Ohio
Posts: 1,416
Likes: 0
Received 0 Likes
on
0 Posts
Car: 84 Z28
Engine: 355 (fastburn heads, LT4 HOT cam)
Transmission: 700R4
Axle/Gears: 9-bolt, 3.27
How are you testing the alternator? If you're just checking the voltage, you're just getting a SMALL part of the story. You really need to test the ouput in AMPs. Just a simple on/off load tester is sufficient in most cases, but a variable, carbon pile load tester is the prefered method, along with the newer capacitance testers. Simply put, if the alt is 1/3 dead, it probably will not be able to maintain 10.5 volts for 15 seconds at the load test rating.
If you don't have the means to test it, go somewhere that does, preferably a shop, not the parts store, parts stores sell parts as their businees, and shops fix car as their business.
If you don't have the means to test it, go somewhere that does, preferably a shop, not the parts store, parts stores sell parts as their businees, and shops fix car as their business.
#11
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
finally
rebuilt the alternator since it killed my battery. problem solved. although, now I'm getting a new noise. I understand that the clicking noise under the hood is the Mixture Control Solenoid, and I know what the choke buzzer sounds like. This new noise is a lound clicking from inside the car. The choke light is also flashing rapidly. It doesn't do it every time I try to start the engine, even on cold starts.
So, I'm looking at :
1) loud clicking noise (in the inconvenience panel)
2) flashing choke light
3) during some cold starts, but not all cold starts
4) during some hot starts, but not all hot starts
choke relay?
So, I'm looking at :
1) loud clicking noise (in the inconvenience panel)
2) flashing choke light
3) during some cold starts, but not all cold starts
4) during some hot starts, but not all hot starts
choke relay?
#12
Moderator
iTrader: (14)
Join Date: Mar 2000
Location: Littleton, CO USA
Posts: 43,169
Likes: 0
Received 36 Likes
on
34 Posts
Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
What's the alternator output voltage now?
I got that funny clicking noise when mine was putting out too high of charging voltage.
I got that funny clicking noise when mine was putting out too high of charging voltage.
#13
Supreme Member
Join Date: Jan 2004
Location: Western Ky
Posts: 1,206
Likes: 0
Received 3 Likes
on
3 Posts
Car: Z/28..39 Plymouth truck in progress
Engine: S/B
Transmission: Manual
Originally posted by JP84Z430HP
How are you testing the alternator? If you're just checking the voltage, you're just getting a SMALL part of the story. You really need to test the ouput in AMPs. Just a simple on/off load tester is sufficient in most cases, but a variable, carbon pile load tester is the prefered method, along with the newer capacitance testers. Simply put, if the alt is 1/3 dead, it probably will not be able to maintain 10.5 volts for 15 seconds at the load test rating
How are you testing the alternator? If you're just checking the voltage, you're just getting a SMALL part of the story. You really need to test the ouput in AMPs. Just a simple on/off load tester is sufficient in most cases, but a variable, carbon pile load tester is the prefered method, along with the newer capacitance testers. Simply put, if the alt is 1/3 dead, it probably will not be able to maintain 10.5 volts for 15 seconds at the load test rating
#14
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Originally posted by five7kid
What's the alternator output voltage now?
What's the alternator output voltage now?
I went back to the shop that rebuilt my alternator for an 'on-vehicle' test, and they said it's doing fine. The clicking only happened once so far today, and not at the time when the voltage was being tested.
#15
Member
Join Date: Oct 2003
Location: Ontario
Posts: 282
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 pontiac trans am
Engine: Block #14010209...350...80-85
Transmission: 700 R4
choke relay?
does it goet louder when you turn on your lights or more constant? and does the sound come from as if it were inside the dash? if yes choke relay.
#16
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
I didn't turn on the lights when it was happening. Yes, it does sound like it's coming from the dash, which leads me to believe it's the choke relay. But, it's not buzzing; just a loud ticking. The Mixture Control Solenoid clicks and stops as it should, but the clicking inside the dash doesn't seem to stop unless I start the engine.
#17
Supreme Member
Join Date: Feb 2000
Location: Johnstown, Ohio
Posts: 1,416
Likes: 0
Received 0 Likes
on
0 Posts
Car: 84 Z28
Engine: 355 (fastburn heads, LT4 HOT cam)
Transmission: 700R4
Axle/Gears: 9-bolt, 3.27
I'm glad this post has been brought up again! I'm now having the same problem, but haven't even thought about looking into it. (trans went last week, finished the replacement, the today something developed a BIG trans fluid leak, had a bad day!)
Back on to topic, the first thing I'm gonna do is test the alt for load, and A/C. I've noticed it doesn't seem to keep up as well with everything turned on!
Did you maybe fry the choke relay with the alt being bad? I'll post back if I ever get mine fixed!
Back on to topic, the first thing I'm gonna do is test the alt for load, and A/C. I've noticed it doesn't seem to keep up as well with everything turned on!
Did you maybe fry the choke relay with the alt being bad? I'll post back if I ever get mine fixed!
#18
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
update
Originally posted by curtis84ta
does it goet louder when you turn on your lights or more constant? and does the sound come from as if it were inside the dash? if yes choke relay.
does it goet louder when you turn on your lights or more constant? and does the sound come from as if it were inside the dash? if yes choke relay.
#19
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Originally posted by JP84Z430HP
Did you maybe fry the choke relay with the alt being bad?
Did you maybe fry the choke relay with the alt being bad?
#20
Supreme Member
Join Date: Feb 2000
Location: Johnstown, Ohio
Posts: 1,416
Likes: 0
Received 0 Likes
on
0 Posts
Car: 84 Z28
Engine: 355 (fastburn heads, LT4 HOT cam)
Transmission: 700R4
Axle/Gears: 9-bolt, 3.27
Now that I think of it, if the relay was shorted (the control, or coil side) it wouldn't work, and may blow a fuse, or cause the relay coil to act as a fuse and open up. Basically, I don't think the realy being bad would make it buzz, but something else would have to be causing it. Not 100% sure about this though, I have seen some pretty weird stuff before, in simple circuits such as this one!
#21
Moderator
iTrader: (14)
Join Date: Mar 2000
Location: Littleton, CO USA
Posts: 43,169
Likes: 0
Received 36 Likes
on
34 Posts
Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Replace the choke relay. If it is clicking with 13.8 volts, and doesn't click when the voltage drops (lights on), it's on its way out.
#22
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Originally posted by five7kid
Replace the choke relay. If it is clicking with 13.8 volts, and doesn't click when the voltage drops (lights on), it's on its way out.
Replace the choke relay. If it is clicking with 13.8 volts, and doesn't click when the voltage drops (lights on), it's on its way out.
#24
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Originally posted by Apeiron
I've never been charged shipping on a part by any GM dealer.
I've never been charged shipping on a part by any GM dealer.
#25
Moderator
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes
on
8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Now that I think about it, I've never been charged shipping by NAPA or any other parts supplier either.
#26
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Anybody have the part number for the choke relay? The closest I got was the GM parts guy quoting me $100 for the choke thermostat (that goes on the side of the carb, which I replaced a long time ago, but I don't remember it costing me $100). "I don't know about anything that works with the choke inside the dash," he said.
#27
Member
Join Date: Oct 2003
Location: Ontario
Posts: 282
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 pontiac trans am
Engine: Block #14010209...350...80-85
Transmission: 700 R4
the choke relay is inside the dash under your steering colum on the right side (in my car anyways) and its on this little board which connects acouple relays. it should cost like 5-10 bux i can't remember but it was minimal. i actually saved the box it came with and kept the receipt so your lucky. part number for my 84 trans am for hte choke relay is; 1408 9568
hope this helps
edit: thats the part number on my receipt which i got from GM
hope this helps
edit: thats the part number on my receipt which i got from GM
Last edited by curtis84ta; 09-11-2004 at 10:09 AM.
#29
Member
Thread Starter
Join Date: Oct 2003
Location: Alabama
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z-28
Engine: L69
Transmission: 700-R4
Thanks for the part numbers guys. It'll probably be a while until I have time to work on the car, but I'll post the results when I get it done.
Thread
Thread Starter
Forum
Replies
Last Post