where do I start ??????
#1
06-02-2007, 12:35 AM
where do I start ??????
First off, I'm new to the forums and they seem great. I have just read through about 50 pages and have to stop becuase my eyes hurt. I just bought a 1987 vette with the 4+3 manual. So far I love it, other than a few electrical gremlins. Any advice on the following items is greatly appriciated.
1) After driving for about 5 to 10 minutes my speedo stops working. It stays lit, but reads zero. It will come back on now an then. When this goes out, my Overdrive 4+3 starts acting funny and stops going into overdrive. I'm think this is a short or heat related since everything works fine when I start up. Maybe the SPEED SENSOR, if this faults out it could be causing my Overdrive to zero speed and stop working????
2) My brake lights and turnsignal work fine, but my taillights won't work......and how the heck do you get to the bulbs anyhow, that's where I wanted to start.
3) how do I get my "fault codes" without buying any special tools, I'm not sure where to look but I heard of a way of jumpering this thing to get the codes. I have a service engine soon light come on after about 5 to 10 minutes of driving. The main Cat Converter has been removed, maybe that is it.
Other things for a later date............My A/C don't work, but from looking a past threads this could be a long fix. I'm also thinking about removing everything to do with my VATS system, just for one less thing to go wrong. Next will be simple horse power mods I hope. Sorry so "wordy" just have tons of questions. Thanks for any help.
1) After driving for about 5 to 10 minutes my speedo stops working. It stays lit, but reads zero. It will come back on now an then. When this goes out, my Overdrive 4+3 starts acting funny and stops going into overdrive. I'm think this is a short or heat related since everything works fine when I start up. Maybe the SPEED SENSOR, if this faults out it could be causing my Overdrive to zero speed and stop working????
2) My brake lights and turnsignal work fine, but my taillights won't work......and how the heck do you get to the bulbs anyhow, that's where I wanted to start.
3) how do I get my "fault codes" without buying any special tools, I'm not sure where to look but I heard of a way of jumpering this thing to get the codes. I have a service engine soon light come on after about 5 to 10 minutes of driving. The main Cat Converter has been removed, maybe that is it.
Other things for a later date............My A/C don't work, but from looking a past threads this could be a long fix. I'm also thinking about removing everything to do with my VATS system, just for one less thing to go wrong. Next will be simple horse power mods I hope. Sorry so "wordy" just have tons of questions. Thanks for any help.
#2
06-02-2007, 08:11 AM
RE: where do I start ??????
ORIGINAL: dans87vette
First off, I'm new to the forums and they seem great. I have just read through about 50 pages and have to stop becuase my eyes hurt. I just bought a 1987 vette with the 4+3 manual. So far I love it, other than a few electrical gremlins. Any advice on the following items is greatly appriciated.
1) After driving for about 5 to 10 minutes my speedo stops working. It stays lit, but reads zero. It will come back on now an then. When this goes out, my Overdrive 4+3 starts acting funny and stops going into overdrive. I'm think this is a short or heat related since everything works fine when I start up. Maybe the SPEED SENSOR, if this faults out it could be causing my Overdrive to zero speed and stop working????
2) My brake lights and turnsignal work fine, but my taillights won't work......and how the heck do you get to the bulbs anyhow, that's where I wanted to start.
3) how do I get my "fault codes" without buying any special tools, I'm not sure where to look but I heard of a way of jumpering this thing to get the codes. I have a service engine soon light come on after about 5 to 10 minutes of driving. The main Cat Converter has been removed, maybe that is it.
Other things for a later date............My A/C don't work, but from looking a past threads this could be a long fix. I'm also thinking about removing everything to do with my VATS system, just for one less thing to go wrong. Next will be simple horse power mods I hope. Sorry so "wordy" just have tons of questions. Thanks for any help.
First off, I'm new to the forums and they seem great. I have just read through about 50 pages and have to stop becuase my eyes hurt. I just bought a 1987 vette with the 4+3 manual. So far I love it, other than a few electrical gremlins. Any advice on the following items is greatly appriciated.
1) After driving for about 5 to 10 minutes my speedo stops working. It stays lit, but reads zero. It will come back on now an then. When this goes out, my Overdrive 4+3 starts acting funny and stops going into overdrive. I'm think this is a short or heat related since everything works fine when I start up. Maybe the SPEED SENSOR, if this faults out it could be causing my Overdrive to zero speed and stop working????
2) My brake lights and turnsignal work fine, but my taillights won't work......and how the heck do you get to the bulbs anyhow, that's where I wanted to start.
3) how do I get my "fault codes" without buying any special tools, I'm not sure where to look but I heard of a way of jumpering this thing to get the codes. I have a service engine soon light come on after about 5 to 10 minutes of driving. The main Cat Converter has been removed, maybe that is it.
Other things for a later date............My A/C don't work, but from looking a past threads this could be a long fix. I'm also thinking about removing everything to do with my VATS system, just for one less thing to go wrong. Next will be simple horse power mods I hope. Sorry so "wordy" just have tons of questions. Thanks for any help.
Don't pull the anti-theft yet. A ground in that system might be one of the common grounds necessary for other functions.
Could be, if you're of faith, that everything works perfectly, except for loose connections.
A few other forum members here can tell which two ALDL pins to jump with the paper clip. When you get that trick done, look closely at the diagram, to see if faulty indicators are on the same circuit. Again - not fun, but it's the right way to fix it.
#3
06-02-2007, 10:36 AM
RE: where do I start ??????
Thanks for the advice. I did find my taillight fuse blown, I know it wasn't a few days ago becuase I checked them all. I'll see how long it goes without blowing again before I get to worried on that.
Now, onto my speedo problem. Has anyone every had their SPEED SENSOR go bad or work intermittently on them? I'm still thinking that may be the cause of the "zero" speedo readings I get now and then, but I'm not sure. I has to be in that circuit if not because the only things effected are that related to speed (i.d. speedo and the 4+3 overdrive.)
Now, onto my speedo problem. Has anyone every had their SPEED SENSOR go bad or work intermittently on them? I'm still thinking that may be the cause of the "zero" speedo readings I get now and then, but I'm not sure. I has to be in that circuit if not because the only things effected are that related to speed (i.d. speedo and the 4+3 overdrive.)
#4
06-02-2007, 12:59 PM
RE: where do I start ??????
ORIGINAL: dans87vette
Thanks for the advice. I did find my taillight fuse blown, I know it wasn't a few days ago becuase I checked them all. I'll see how long it goes without blowing again before I get to worried on that.
Now, onto my speedo problem. Has anyone every had their SPEED SENSOR go bad or work intermittently on them? I'm still thinking that may be the cause of the "zero" speedo readings I get now and then, but I'm not sure. I has to be in that circuit if not because the only things effected are that related to speed (i.d. speedo and the 4+3 overdrive.)
Thanks for the advice. I did find my taillight fuse blown, I know it wasn't a few days ago becuase I checked them all. I'll see how long it goes without blowing again before I get to worried on that.
Now, onto my speedo problem. Has anyone every had their SPEED SENSOR go bad or work intermittently on them? I'm still thinking that may be the cause of the "zero" speedo readings I get now and then, but I'm not sure. I has to be in that circuit if not because the only things effected are that related to speed (i.d. speedo and the 4+3 overdrive.)
Intermittent electrical function can be caused by a bad ground. Sorry, I thought I mentioned that.
And occasionally, other electrical functions share a common ground.
Get a voltmeter, and get a wiring diagram.
#5
06-02-2007, 04:03 PM
RE: where do I start ??????
Yep, I spent most of today looking thru electrical schematics for the car. I couldn't find the Speed Sensor on any 1987 circuit, though I did find it on a 90's schematic. I'm going to start looking thru the circuit were it shows on the 90's schematic, starting with the grounds first. I did notice one other clue today. The SPEEDO still stops working after about 10 minutes, but it's after a stop usually. Seems to come back on after I get going a while. Well, back to digging thru wiring and schematics. Thanks again.
#7
06-02-2007, 08:32 PM
RE: where do I start ??????
Speed sensor is in the tailshaft of your trans. You can check it with an a/c voltmeter. If it has output, you will get a/c voltage, not you will get none or almost none, also will increase in amplitude when speed rises. Raise back wheels and put on jackstands for testing. You will need some one in car and unplug sensor and test at the sensor on the two terminals. Good Luck.
#8
06-02-2007, 09:05 PM
RE: where do I start ??????
I was thinking the speed sensor was in the real wheel also on the manuals, but mech259 seems to know a ton about C4's so I probably guessed wrong. I start looking tomorrow.
#10
06-03-2007, 12:16 PM
RE: where do I start ??????
It IS on the trannsmission because my speedometer does not work. I pulled it out of the trann and it looked dirty**yes a little fluid came out**and i sprayed it with penetraing lube just to see what it would do. Before I did this, the speedometer went crazy. Now it stays at zero. So its shot. Its about 100 dollars from Advanced here but....I feel thats a bit high.