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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!
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?
Gauge Resistor? Are you talking about the resistor for the dimming lights?
Gauge Resistor? Are you talking about the resistor for the dimming lights?
Apparently on the '87 there is a resistor in the gauge cluster which replaces the previous battery/alternator bulb. The resistor and previous bulb have to be working to send the exciter signal to the alternator to start charging.
Boy, I’d love to transfer the back pockets to the new seats, but that might be a big can of worms.
An upholstery shop should be able to do it easily, and it's not likely to cost much. Take apart the seats, then peel up the seat covers and take them to the shop. The'll split the rear seams, then remove the pockets from the old covers and sew them into the new covers. And if you feel that the old elastic is too stretched out, then they can probably sew in some new elastic too.
I may have a grounding issue. I'm getting 0.2 -0.3 Ohms everywhere. Shouldn't it be 0.05 ohms or less?
A couple of things. Was your meter zeroed out? Also, a resistance (ohm) test is not the best way to find an issue with the circuit, especially for load circuits. A voltage drop test is better.
A member from from my FB page came over and helped me with my electrical gremlins His favorite thing on our cars are electricals. He figured everything out in less than an hour. It was a bulb, fuse and relay.
A member from from my FB page came over and helped me with my electrical gremlins His favorite thing on our cars are electricals. He figured everything out in less than an hour. It was a bulb, fuse and relay.
What exactly was the issue with the alternator not charging and the Choke Light on? It might help to update your threads to help others. Actually, I'm really curious to know myself.
What exactly was the issue with the alternator not charging and the Choke Light on? It might help to update your threads to help others. Actually, I'm really curious to know myself.
1) Okay, let's start with the choke heat relay. I have not been able to find any modern replacements . Yes, they are listed as replacements, but they are wrong. They don't fit. I found a GM NOS part number 10034222. I found one on eBay and installed it. It didn't work and I have to find another. We did jump the connector and the choke light went off and new choke appears to work normally.
2) The issue with the brake pedal turning on the door buzzer, front lights, gauge lights, was the fault of an incorrect bulb in the brake lights. The ONLY one I didn't change, because it worked and looked new. I kept going back to the rusted sockets which I had cleaned and replaced bulbs..
3) The 20 amp, fan fuse was blown. I never even thought to check that one. It controls the fan, alternator and you guessed it, choke.
Did you install the old Choke heater relay after replacing the 20 amp fuse? That 20 amp fan fuse is also part of the choke heater relay, so if that fuse was blown then the choke heater circuit would not work correctly either.
I would doubt your original old choke heater relay is actually bad. Based on our discussions and how the circuit works, I was skeptical that it was bad.
Then again, I'm not there. While I'm not any expert, I also like electrical work.
Did you install the old Choke heater relay after replacing the 20 amp fuse? That 20 amp fan fuse is also part of the choke heater relay, so if that fuse was blown then the choke heater circuit would not work correctly either.
I would doubt your original old choke heater relay is actually bad. Based on our discussions and how the circuit works, I was skeptical that it was bad.
Then again, I'm not there. While I'm not any expert, I also like electrical work.
Yes, tried the old and the "new" relay after the fuse and both were bad. . I just ordered another NOS GM relay. These things are decades old. I hope this one works.
Yes, tried the old and the "new" relay after the fuse and both were bad. . I just ordered another NOS GM relay. These things are decades old. I hope this one works.
I was going to edit my message to correct myself to prevent confusion. I was thinking of the pre 1987 VIN H choke relay, where the relay is "normally closed", when I stated I had doubts the relay was bad.
In the 1987 application, the relay is "normally open", which is more common, and I can see that failing and not working.
So it sounds like you're on the right track. Unless you still have an issue with the oil pressure switch. That switch is necessary for the choke heater operation. I'm not sure exactly what terminals you jumped, but I'm guessing you bypassed the oil pressure switch so that still could be the issue. Not enough info to know.
Very old decals which came with the car. Those little pieces should come off in a sheet. I needed an X-acto blade to pick them off. We’ll see what we’ll get.
If you're jumping the Brown/White to Light Blue that will power up the choke heater circuit whenever the key is On. That will work but keep in mind what you're doing is not just bypassing the relay, but also bypassing the circuit that enables the relay.
In other words, this does not mean the relay itself is absolutely certain to be bad. It could be the circuit that powers the relay, as we discussed, which is via the oil pressure switch while also powers your in tank fuel pusher pump is bad.
A relay is simply a higher current, electrically operated, On/Off "switch". If you're jumping the Brown/White to Light Blue wires then you're simply making it an On switch. Again, the relay could be bad or the circuit could be bad. It seems pretty likely it's the circuit, and possibly the oil pressure switch.
If you're jumping the Brown/White to Light Blue that will power up the choke heater circuit whenever the key is On. That will work but keep in mind what you're doing is not just bypassing the relay, but also bypassing the circuit that enables the relay.
In other words, this does not mean the relay itself is absolutely certain to be bad. It could be the circuit that powers the relay, as we discussed, which is via the oil pressure switch while also powers your in tank fuel pusher pump is bad.
A relay is simply a higher current, electrically operated, On/Off "switch". If you're jumping the Brown/White to Light Blue wires then you're simply making it an On switch. Again, the relay could be bad or the circuit could be bad. It seems pretty likely it's the circuit, and possibly the oil pressure switch.
Is there a simple way for me to test the oil pressure switch so I’m not simply being a parts swapper?
Is there a simple way for me to test the oil pressure switch so I’m not simply being a parts swapper?
There should be a Tan/White wire at that harness. With the car running, if the oil pressure switch is working, you should see 12 volts on that wire. So use a meter and have Tan/White wire on positive lead and the negative to any good ground.
There should be a Tan/White wire at that harness. With the car running, if the oil pressure switch is working, you should see 12 volts on that wire. So use a meter and have Tan/White wire on positive lead and the negative to any good ground.
What do you have across the other two, smaller outside pins? I haven't seen a wiring diagram, but based on the above pics & comments I would assume one of those connections come from the oil pressure switch & the other is either a ground or 12V depending on what the oil pressure switch is providing the relay coil.
What does your meter show across those two pins, key on vs engine running & then each of those 2 pins to a ground key on vs engine running & then again to 12V. key on vs engine running Note the last 4 tests in both voltage & ohms for resistance to see what if anything changes. You should have something different between key on & engine running on one of those two wires if all that triggers the relay is the oil pressure switch. Either a provided ground when the engine is running, or a proved 12v on one of those two smaller wires.
Just my random thoughts from reading the last couple of posts.
Here would be my recommendation for your choke diagnosing.
#1 First check fuse #2 10A should be labeled FP/INJ2
#2 If the fuse looks good, check to make sure the fuse has 12V with the key on on both of its test points on the sides of fuse
#3 If the fuse is good & you have 12V, then remove the fuel pump relay plug & check to make sure you have 12V on the orange wire with the key on
#4 If you have 12V on the orange wire, put your meter on the purple/white wire on the plug & make sure you have 12v only while cranking the engine.
#5 If you have 12V on the purple/white wire while cranking, plug the relay back in & do the same cranking voltage test on the tan/white wire on the choke relay plug.
#6 If you have 12V while cranking, plug that relay back in & see if you have 12V at the carb on the light blue choke wire while cranking.
#7 If you get that far and have all those voltages, time to check your oil pressure switch. Not sure how accessible it is on your car, but you could unplug that pressure switch & jump across the two wires on the plug
just like you did on the choke plug & see if the choke has power with the key on, not running. That would confirm its the pressure switch.
You could also possibly save yourself some time, by just plugging in both relays in & skip right to step #6. if that test fails, then go back & start at step #1
If you have cranking voltage in step #6 then go to step #7
the wires on the oil pressure switch to jump out should be orange & Tan/white Service manual shows those wires in a harness across the intake manifold, so Im guessing the switch is back of the block by the distributor.
The diagram from the 1987 shop manual was posted elsewhere and we've been using it to help Charlie:
There's more than one way to diagnose these issues. I suggested starting from front to back because Charlie was already at the heater relay and it's easier to get access to and it will confirm if the relay itself is bad or not. Reason why we're checking the coil power at the heater relay is because that's an easier spot to check for the 12volt out of the oil pressure switch, providing it's working, since the oil pressure switch is more difficult to access.
Due to the design of the circuit and the Choke light, you will get voltage at the choke heater that comes through the Choke light as it (choke light) will act as a small resistor if the heater relay is not operating. So step 6 will show voltage, even with a bad or inoperative relay.
If the engine is not running (no oil pressure and so no choke heater relay), the Choke light will illuminate as it will ground through the choke heater. Testing this will show voltage through the Choke light. Once the engine is running and there's oil pressure, the choke heater relay is energized that provides full power to the choke heater as well as "cancels" the Choke light as it will have two hots and no longer a ground path.
Originally Posted by F-body-fan
Here would be my recommendation for your choke diagnosing.
#1 First check fuse #2 10A should be labeled FP/INJ2
#2 If the fuse looks good, check to make sure the fuse has 12V with the key on on both of its test points on the sides of fuse
#3 If the fuse is good & you have 12V, then remove the fuel pump relay plug & check to make sure you have 12V on the orange wire with the key on
#4 If you have 12V on the orange wire, put your meter on the purple/white wire on the plug & make sure you have 12v only while cranking the engine.
#5 If you have 12V on the purple/white wire while cranking, plug the relay back in & do the same cranking voltage test on the tan/white wire on the choke relay plug.
#6 If you have 12V while cranking, plug that relay back in & see if you have 12V at the carb on the light blue choke wire while cranking.
#7 If you get that far and have all those voltages, time to check your oil pressure switch. Not sure how accessible it is on your car, but you could unplug that pressure switch & jump across the two wires on the plug
just like you did on the choke plug & see if the choke has power with the key on, not running. That would confirm its the pressure switch.
You could also possibly save yourself some time, by just plugging in both relays in & skip right to step #6. if that test fails, then go back & start at step #1
If you have cranking voltage in step #6 then go to step #7
the wires on the oil pressure switch to jump out should be orange & Tan/white Service manual shows those wires in a harness across the intake manifold, so Im guessing the switch is back of the block by the distributor.
Taking a break from that stuff and working on cosmetics for ThirdGen Expo this Sunday. I’ve decided not to used the ‘91 Formula seats since they have some differences to mine and that would bug me. But I’m starting to cannibalize them to improve my seats. Swapped headrests for starters.
The diagram from the 1987 shop manual was posted elsewhere and we've been using it to help Charlie:
There's more than one way to diagnose these issues. I suggested starting from front to back because Charlie was already at the heater relay and it's easier to get access to and it will confirm if the relay itself is bad or not. Reason why we're checking the coil power at the heater relay is because that's an easier spot to check for the 12volt out of the oil pressure switch, providing it's working, since the oil pressure switch is more difficult to access.
Due to the design of the circuit and the Choke light, you will get voltage at the choke heater that comes through the Choke light as it (choke light) will act as a small resistor if the heater relay is not operating. So step 6 will show voltage, even with a bad or inoperative relay.
If the engine is not running (no oil pressure and so no choke heater relay), the Choke light will illuminate as it will ground through the choke heater. Testing this will show voltage through the Choke light. Once the engine is running and there's oil pressure, the choke heater relay is energized that provides full power to the choke heater as well as "cancels" the Choke light as it will have two hots and no longer a ground path.
The bulb is an important detail for sure! On the diagram I have it just says instrument cluster, I Didn't realize there was a 12V source thought the bulb filament.
Completely missed that info as I hadn't been following the entire thread. I just kinda jumped in after Charlie & I were messaging about about it.
So I guess the easiest right now would be to keep the choke relay pulled & test the tan/white for voltage during cranking, & if he has that, then check for voltage at the oil pressure switch with the key on, if he does, then jump that out, turn the key on again & see if there is now voltage on the brown/white seeing he can already jump out the brown/white & Light blue & the chock opens up, he's awfully close to finding his issue.
Question though, how is the car running & driving? it would appear the pressure switch has to be functioning to be getting any fuel pressure after crank starting.
The bulb is an important detail for sure! On the diagram I have it just says instrument cluster, I Didn't realize there was a 12V source thought the bulb filament.
Completely missed that info as I hadn't been following the entire thread. I just kinda jumped in after Charlie & I were messaging about about it.
So I guess the easiest right now would be to keep the choke relay pulled & test the tan/white for voltage during cranking, & if he has that, then check for voltage at the oil pressure switch with the key on, if he does, then jump that out, turn the key on again & see if there is now voltage on the brown/white seeing he can already jump out the brown/white & Light blue & the chock opens up, he's awfully close to finding his issue.
Question though, how is the car running & driving? it would appear the pressure switch has to be functioning to be getting any fuel pressure after crank starting.
Hmmmm.
I'm not as familiar with the LG4 and GM's carb setup, but people here have stated the mechanical fuel pump can pull fuel through an in-tank fuel pump that's not working.
I'm not as familiar with the LG4 and GM's carb setup, but people here have stated the mechanical fuel pump can pull fuel through an in-tank fuel pump that's not working.
It has both electric & mechanical? I had no idea. I wonder why that would be needed?
Did GM plan to have an LG4 Dual carb tunnel ram option that got scrapped right before production?
Runs pretty well, once the choke circuit is jumped. It could use a tune up, though. All the tune up parts have been sitting on my bench for several weeks. I won't get to that before Expo.
Yes, my car has both a mechanical fuel pump, located in the standard location on the block and an electric fuel pump in the tank. I believe GM did that to resist vapor lock. If anyone knows something else, please chime in.
Is the backing on your floor mats bad? Looks like you had the originals in your first picture but now you've gotten some off-roading floor mats in one of your last pictures? I need a pair or three but they're a little pricey.
Is the backing on your floor mats bad? Looks like you had the originals in your first picture but now you've gotten some off-roading floor mats in one of your last pictures? I need a pair or three but they're a little pricey.
Pictures from events like this usually show way more Camaros than Firebirds but looks like A LOT of Firebirds there. Tight parking for the big doors on 3rdgens.
Two white Formulas with open hoods are visible. One is four cars up the line, looks solid white with t-tops. Looks like yours under the light pole, white hardtop with dark lower body and black spoiler.
Pictures from events like this usually show way more Camaros than Firebirds but looks like A LOT of Firebirds there. Tight parking for the big doors on 3rdgens.
Two white Formulas with open hoods are visible. One is four cars up the line, looks solid white with t-tops. Looks like yours under the light pole, white hardtop with dark lower body and black spoiler.
Where in the "Chicagoland" was this?
This was in Addison il. It's my annual event.
A gaggle of 'Birds in this picture, but it was about 50-50. Yes, that's mine by the light pole.
07-04-2023, 11:04 AM
