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History / OriginalityGot a question about 1982-1992 Camaro or Firebird history? Have a question about original parts, options, RPO codes, when something was available, or how to document your car? Those questions, answers, and much more!
Try checking the C/H Fan Fuse. It's a 20 AMP fuse.
If I understand the circuit correctly, if that fuse is not working and going to the Choke Heater Relay, the Choke Warning light will find a ground through the choke heater and do what you're describing.
Thanks JT, checked the fuse last night. It looked good, but replaced it anyway. My next step is the Choke Heater Relay. Are there any good illustrations of which relay it is?
Thanks JT, checked the fuse last night. It looked good, but replaced it anyway. My next step is the Choke Heater Relay. Are there any good illustrations of which relay it is?
The service manual says it's in the Convenience Center, which is further defined as behind the instrument panel to the right of the steering column.
I would go by wire colors. This is for 1985 since I don't have a 1987 manual:
One slot should have two brown wires
One slot should have one brown wire
One slot should have two light blue wires
If I understand the circuit and if it's the same in 1985, I doubt the relay is bad as it would have to be stuck On to replicate your issue. Relays can stick On but I would think it's less likely to do so and remain stuck. So, like T.L. posted in the Carb forum, it's possible the relay is missing, disconnected or a wire disconnected.
The service manual says it's in the Convenience Center, which is further defined as behind the instrument panel to the right of the steering column.
I would go by wire colors. This is for 1985 since I don't have a 1987 manual:
One slot should have two brown wires
One slot should have one brown wire
One slot should have two light blue wires
If I understand the circuit and if it's the same in 1985, I doubt the relay is bad as it would have to be stuck On to replicate your issue. Relays can stick On but I would think it's less likely to do so and remain stuck. So, like T.L. posted in the Carb forum, it's possible the relay is missing, disconnected or a wire disconnected.
This is not my strong area, but as far as I can tell, my choke/choke light problem can only be from the fuse, relay or failing alternator. Any other sources?
This is not my strong area, but as far as I can tell, my choke/choke light problem can only be from the fuse, relay or failing alternator. Any other sources?
Relays come in different configurations - such as normally open and normally closed. A lot of relays that you come across in the automotive field work on the normally open configuration. Normally open means the relay must be powered so that it can close the internal contacts to pass current to the load side of the relay and power up whatever circuit the relay was intended to supply. However, not all relays work that way. Some relays work in the exact opposite behavior.
This circuit uses a normally closed relay. Meaning, the relay passes current to the load side of the relay whenever the relay is not powered. When the relay is powered, the relay breaks the contacts to the load side.
This operation makes the choke light work when the Key is ON and Engine is Off while the choke heater is Off. When the Key is On and the Engine is Running, the choke heater is On and the choke light is off. Yes, the alternator is part of this circuit by providing voltage to the relay coil and thus kicking the relay Off. However, remember, when the relay is Off the choke heater is On.
This is not my strong area, but as far as I can tell, my choke/choke light problem can only be from the fuse, relay or failing alternator. Any other sources?
By the way, now that you mention the alternator, didn't you earlier say that you had a charging system issue or was it just a bad battery?
If the alternator is not outputting voltage, or the circuit from the alternator to the choke heater relay is broken, then you will also have the issue you describe. The alternator, when the engine is running, needs to generate a current to disrupt the relay coil and turn the relay Off so that the choke light turns off and the choke heater operates when the engine is running. However, what you describe can also happen if the relay is missing, disconnected, the fuse is blown or missing, or any of the circuit is not flowing (broken wires).
Yes, I had a charging problem. But I put the battery on a charger for a full day and that seemed to fix it. Since then I've checked the battery and alternator with a meter numerous times and they are normal But I did read in one of the threads that sofakingdom said to check the alternator regulator.
The "convenience center", I'm not sure how you access it.
Yes, I had a charging problem. But I put the battery on a charger for a full day and that seemed to fix it. Since then I've checked the battery and alternator with a meter numerous times and they are normal But I did read in one of the threads that sofakingdom said to check the alternator regulator.
The "convenience center", I'm not sure how you access it.
I think that's the hush panel under the steering column/instrument cluster.
I don't know, it's possibly unrelated and a detour, but unless the battery was weak and/or not used much, I would be skeptical that you had to charge the battery. Especially since, I recall, you had this happen while you was actually driving.
I think that's the hush panel under the steering column/instrument cluster.
I don't know, it's possibly unrelated and a detour, but unless the battery was weak and/or not used much, I would be skeptical that you had to charge the battery. Especially since, I recall, you had this happen while you was actually driving.
Yes, died while driving. A good samaritan gave me a jump and I was on my way. Maybe I'll get a meter on it tonight.
Oh, how easy it would be to just get a new alternator and have this issue fixed. But I'm trying to resist just changing parts randomly.
Yes, I think that slot in the bottom center is where it should be. I don't have an LG4, so I'm guessing the wiring is integrated like it is for the flasher?
The relay itself is a 3 terminal, and it matches that slot.
I wonder if it was moved on 1987s? I was going off of my 1985 service manual thinking they should be the same, but that was the last year for the old cluster so there was some changes made.
I cleaned the contacts and re-installed. Choke light went momentarily off and then came back on again. I don't know what that means, but it's something.
I cleaned the contacts and re-installed. Choke light went momentarily off and then came back on again. I don't know what that means, but it's something.
When the key was On and Engine Off? Or while Engine Running?
If the latter, I would suspect a connection issue with the alternator circuit or maybe alternator itself. Does it change depending on RPM?
It's also possible the relay is stuck. You could disconnect the relay and use an OHM meter across the terminals of the relay. Without seeing the relay, I can't tell you which terminals are what but between two terminals should be nearly 0 ohms and the other two should be in the 2 or 3 digit ohm reading.
On another thought, I suppose it's possible the contacts in the relay are bad and barely making a connection. That could also cause the issue you're having. If so, the test above should show that.
Yes, I think that slot in the bottom center is where it should be. I don't have an LG4, so I'm guessing the wiring is integrated like it is for the flasher?
The relay itself is a 3 terminal, and it matches that slot.
This is the actual heat choke relay which looks different than the one listed as a replacement
NEW THING: Right turn signal arrow goes on when I hit the brakes. I'm assuming this is unrelated.
I have had that happen with other cars or trailers and often meant a bad ground and the circuit for the brakes ends up grounding through the other circuit turning on the light. I'd look for bad bulbs/crusty sockets. Do the cheap/easy first.
I went to part's store and they are out of that relay. Will have one in a couple days. Choke light went off for a few minutes and then came back on.
Still no operable choke. When cold, I have to keep giving it throttle for it not to die. After a few minutes, it idles normally.
NEW THING: Right turn signal arrow goes on when I hit the brakes. I'm assuming this is unrelated.
Also, I'm not a GM carb guy, but I don't know that your choke heater relay (which controls the Choke light) is the reason for your cold idle issue. The choke heater relay simply heats up the choke spring to get the choke to open after a cold start warm up. The choke should be closed for cold start enrichment and slowly open for warm idle.
Maybe your choke and fast idle is not set correctly, however, that would not be why the Choke light is on. The Choke light is a dumb circuit just to inform the driver that the heater circuit may not be functioning. It has no way to know, or any feedback, on the choke operation itself.
I have had that happen with other cars or trailers and often meant a bad ground and the circuit for the brakes ends up grounding through the other circuit turning on the light. I'd look for bad bulbs/crusty sockets. Do the cheap/easy first.
Yeah, I'll go around and look again. There were a couple of bulbs rusted to their sockets when I was changing bulbs. Maybe I missed one.
NEW DISCOVERY!: When I step on the brake, the instrument gauge lights go on as well as the front parking lights. Also the buzzer goes off.
Busy but not productive day. Went around and checked all the bulbs to see if any are shorting. Replaced a couple of questionable ones, but still getting gauge lights. front parking lights and buzzer when applying the brakes.
Figured alternator was toast. 12.5V on battery, 12.5V when running, 11V with load (lights/fan/radio). Before replacing it, I took it to the parts store to be tested. It passed. What the heck.
Busy but not productive day. Went around and checked all the bulbs to see if any are shorting. Replaced a couple of questionable ones, but still getting gauge lights. front parking lights and buzzer when applying the brakes.
Figured alternator was toast. 12.5V on battery, 12.5V when running, 11V with load (lights/fan/radio). Before replacing it, I took it to the parts store to be tested. It passed. What the heck.
I saw your other thread in the Electronics section. There is some common factors with the Choke Light and the excite wire of the alternator that starts the alternator to output for charging. That would also explain why it passed at the auto store but does not charge in the vehicle.
When you start the car, rev up the engine a few times. Does it start charging?
I saw your other thread in the Electronics section. There is some common factors with the Choke Light and the excite wire of the alternator that starts the alternator to output for charging. That would also explain why it passed at the auto store but does not charge in the vehicle.
When you start the car, rev up the engine a few times. Does it start charging?
No, it did not. Also failed when tested under load at another auto parts store. Replaced it today.
I saw your other thread in the Electronics section. There is some common factors with the Choke Light and the excite wire of the alternator that starts the alternator to output for charging. That would also explain why it passed at the auto store but does not charge in the vehicle.
When you start the car, rev up the engine a few times. Does it start charging?
Excite wire, meaning one of the wires in the connector?
Excite wire, meaning one of the wires in the connector?
Keep in mind that post was before LAFireboyd posted the 1987 manual and shows that it's different from the 1985 that I was working off of. The choke light/heater relay is not tied to the charging system in 1987 on the LG4 as it was in 1985 on the LG4.
The brown wire in your 3 wire harness on the alternator goes to the instrument cluster to A)Light the Charge Lamp if not charging (and if lamp is equipped) and B) Receive a slight Hot signal from battery, through a resistor, to power up the alternator so that it can start charging when the engine starts and spins the alternator (if gauge equipped and no lamp). That line is called the "excite" wire as it's need to start the alternator.
This is how an alternator may pass when bench tested (such as at an auto store) but may not work in the car - the car's wiring (such as the excite wire) may not be electrically complete and not allow charging in the car.
Keep in mind that post was before LAFireboyd posted the 1987 manual and shows that it's different from the 1985 that I was working off of. The choke light/heater relay is not tied to the charging system in 1987 on the LG4 as it was in 1985 on the LG4.
The brown wire in your 3 wire harness on the alternator goes to the instrument cluster to A)Light the Charge Lamp if not charging (and if lamp is equipped) and B) Receive a slight Hot signal from battery, through a resistor, to power up the alternator so that it can start charging when the engine starts and spins the alternator (if gauge equipped and no lamp). That line is called the "excite" wire as it's need to start the alternator.
This is how an alternator may pass when bench tested (such as at an auto store) but may not work in the car - the car's wiring (such as the excite wire) may not be electrically complete and not allow charging in the car.
Even with the new alternator, there is no indication that the alternator is charging. So I need to figure out the possible causes. The excite wire makes sense. Wondering if there is a generator bulb or hidden bulb in the IP I have to find?
I think the CLSTR fuse is for the digital cluster option, which Formulas did not have but was on available on the Trans Am and GTA.
Check the Gages 10 AMP fuse as that will prevent the excite wire on the alternator from powering up so that the alternator can charge. However, I think if that fuse is blown you'll have other things not working.
The digital cluster has a hidden bulb for the alternator operation, you should have the resistor.
Remember when I told you that you got the car for a good price? Can I change that? Just kidding, these are all fixable stuff so as long as the condition was there, it's still probably is.
I think the CLSTR fuse is for the digital cluster option, which Formulas did not have but was on available on the Trans Am and GTA.
Check the Gages 10 AMP fuse as that will prevent the excite wire on the alternator from powering up so that the alternator can charge. However, I think if that fuse is blown you'll have other things not working.
The digital cluster has a hidden bulb for the alternator operation, you should have the resistor.
Remember when I told you that you got the car for a good price? Can I change that? Just kidding, these are all fixable stuff so as long as the condition was there, it's still probably is.
I've checked the fuses several times. I may just put a new fuse in "gages" just for the heck of it. My attention is on the gauge resistor. Do we know where it's located and what it looks like?
I've checked the fuses several times. I may just put a new fuse in "gages" just for the heck of it. My attention is on the gauge resistor. Do we know where it's located and what it looks like?
I'm wondering if the book is wrong. I have found this out on non-GM service manuals in the past.
The book shows a 470 ohms resistor between connector C2 (pin 12) Brown wire and connector C1 (pin 9) Pink/Black. The book labels this as "470 ohm generator resistor, located in the cluster".
However, looking at instrument clusters on line, C2 (pin 12) is a dead-end on the circuit board. So either the book is wrong or something changed.
I can tell you for sure there's a hidden bulb in the digital cluster, which matches the book, but doing some quick research it appears the analog cluster is unclear.
Replaced the gauge fuse eventhough it looked good. No change.
Switched batteries with another car, no difference, so not the battery.
Picked up my choke/heat relay, couldn't wait to put it on. The one labeled fuel pump. Nope, looked like it would fit but internal plastic was just different enough for it not to fit.
Number one priority is the charging issue now. The car has limited range on battery only.
I did kick up the fast idle and idle to keep it from dying. It seems like a happy motor over 1,000 RPM.
I'm wondering if the book is wrong. I have found this out on non-GM service manuals in the past.
The book shows a 470 ohms resistor between connector C2 (pin 12) Brown wire and connector C1 (pin 9) Pink/Black. The book labels this as "470 ohm generator resistor, located in the cluster".
However, looking at instrument clusters on line, C2 (pin 12) is a dead-end on the circuit board. So either the book is wrong or something changed.
I can tell you for sure there's a hidden bulb in the digital cluster, which matches the book, but doing some quick research it appears the analog cluster is unclear.
What I am learning is that '87 has a lot of weird stuff. Not '82-'86 and not quite '88-'92.
I'm also searching, JT. If you come up with anything please let me know. But I think my attention is on the exciter resistor located somewhere in the cluster.
What I am learning is that '87 has a lot of weird stuff. Not '82-'86 and not quite '88-'92.
I'm also searching, JT. If you come up with anything please let me know. But I think my attention is on the exciter resistor located somewhere in the cluster.
Well the diagram that LAFireboyd posted, below, is from the 1987 shop manual for VIN H.
You have the "Gages Cluster", which specifically shows "resistor" at the instrument cluster section for Connector C2 Pin 12 and Connector C1 Pin 9.
The "indicator cluster" would be the the very base cluster with the idiot lights instead of the gauges. You don't have that one.
If you have an Ohm meter, you can ohm the wire at C2 Pin 12 Brown with the instrument cluster disconnected and the other end at the alternator's brown wire with it also disconnected.
According to the book, there should be 470 ohms. However, also according to the book, the resistor is in the instrument cluster and so if you do the above you technically should see 0 ohms (or very close).
If you have instrument cluster out, take a good picture of the back showing the printed board so we can review.
One more thing to try if you didn't. Disconnect the 3 pin alternator wire, leave the instrument cluster connected, turn the key to ON (not running) and check for voltage at the brown wire at the 3 pin alternator wire. Negative test lead to ground, and positive test lead to the brown wire. You should see voltage.
Just curious, if the in tank fuel pump wasn't working and fuel relied completely on the mechanical pump, would I notice any drivability issues?
Many carb cars didn't have in-tank fuel pumps to push fuel to the mechanical fuel pump, so it becomes a question as to how well the mechanical fuel pump can draw fuel through the in-tank fuel pump.
That said, I'd think your charging system issue is just as much of a performance/drivability concern when the coil is not getting the designed supply. Especially under higher RPM and load.
People are asking what’s wrong with your fronts seats? They are faded almost off white, have some rips and the driver’s seat had like a blue tint to it, like it’s been dyed. That or the previous owner wore a jean suit for several years. I cleaned up these new seats to replace them.
Current seats.
New seats. Will have to do something about drivers seat rip. They look weird because they are still damp after extraction.
06-18-2023, 09:46 AM
Just kidding, these are all fixable stuff so as long as the condition was there, it's still probably is. 
