I NEED A LITTLE HELP PLEASE. Hey all it is jmn (old user name) I lost my password and have moved so I no longer have my old email address and forgot my old pass. Any way glad to be back. On my 93 lt1 vette I have ran into some issues that I never have before. Here is what is happening.

1st the vats quit recognizing the fob for about 3 months. it started recognizing it again about 3 weeks ago. it would arm and disarm as you walked up to it. As it sat overnight it would not do anything recognize it and was as if it was never set. Now it will not do anything again not even if you push the buttons.

2nd the stereo lights have not worked in about 4 years. tonight they started working. this happened after all my dummy lights came on and car lost power (it did this 8 times within 17 miles). this would last for about 5 seconds or so. when this happens there is a clicking on the drivers side by the windshield.

3rd there has been several times over the last several months where the car will not turn over. I pull the fuses on the passenger side out and put them right back in. The car will then start. It does not seem to be any one in particular that will let it start.

4th The passenger side window goes up some times and some times it wont move. Currently it wont do anything but dim the lights.

5th The optispark was just replaced again last week by the dealer this is my third replacement in 4 years. 2 weeks before it went out the car started backfiring a bit under heavy load. it seems as if it waas backfiring theough the exhaust just every once in awhile. The car has now started backfiring once again.

I am stuck scratching my head. The dealer says the car is in time. I Now believe all of this must be linked to something electrical... Maybe the ECM???? Any help would be apreciated. Jon

 

1. Bad fob, did you try a new battery? Bad receiver in car.
2. Radio needs to be looked at. Intermittent power and clicking are due to low battery voltage. Look at your voltmeter, it should not fall below 12.0 volts (battery discharged). Also, remove battery cables (neg first) and clean the cable lugs, battery terminals, and bolts and replace (neg cable last).
3. If VATS doesn't recognize the pellet resistance it won't allow a start for 6 minutes, just long enough to pull fuses, but not related to fuse pulling. Use search for my explaination of how to check the ign tumbler making connection to the pellet.
4. You will have to check if the window motor is getting 12v and if lights dim, check for excessive window mechanism resistance. Also, window switches aren't very durable, swap window switches and see if window operates.
5. Well, backfiring indicated a defective opti before and probably again.

 

Just took the door APART to look at the motor turned power on and nothing... put door back together turned power on and the window started working and the car started to arm itself again. It will not unlock itself but it will lock itself. The A/c fan switches now have quit working. The battery and cables are new as well as the fob about 6 months old. When the clicking starts and all the warning lights come on the voltage stays up 12 to 14 volts. The back firin started right beofre the opti spark went bad and did not continue the first few days after repair. If anyone is wondering no i do not get the engine or the optispark wet. There just seems to be so many electrical things going on i just wonder if they are not tied together.

 

Two things to start with. . .I am no expert on this by any means. . .2nd. . .these kinds of problems can be hard to diagnose. You may need to bring it to a professional.

With that said, I doubt very much that your opti is bad again. From what you've written that just wouldn't make sense. Something else is causing the backfire. Could be many, many different things.

Chances are, though, that all of these symptoms are related to one cause. One bad wire shorting intermittently can drag the whole system down or cause the computer to go haywire.

That's why I think a professional diagnosis is called for. You could replace expensive part after expensive part and still miss the true problem. But I wouldn't bring it back to the dealer you mentioned. Three opti's in four years? Something's not right about that.

Ask the forum members in your area to recommend a good shop.
Good luck.

 

With such a wide array of bizarre and intermittant electrical gremlins, I'd suggest you clean and secure all engine and chassis grounds that you can find, as well as checking/doing the things that jfb suggested above.

Good luck with it. Please let us know what you find when you get to the bottom of this mess.

Be well,

SJW

 

I am having very similar problems with my car (I have a 92). I am getting ready to trace all the grounds in the car to clean them and make sure they are well connected.

A couple of my problems heal themselves when it is wet out. It is obvious to me that there are grounding problems in my car and I expect that you are running into the same thing. The factory service manual has a whole set of diagrams on just the grounds! I will post my results when I get it done.

 

I just got back from Chevrolet. They checked the alternater and voltage reulater. They tested OK. The car happened to do the all lights on ordeal and now dies as it happens. The voltage on the inside gauge is now hanging around 10 volts was 14 to 16 last night. All the while the dealers outside gauge is staying at a firm 14 volts. the dealer confirmed as so did I that the battery connections are tight. Chevrolet says they do not know where to start looking. Kind of strange that the all lihts and dyin did not statr until this last optispark change happened.
Is there a ground that would have been messed with during this change?
If anyone has a copy of the grounding diagrams or just the locations of them it would be much apreciated if you could forward them to me.

 

I thought I would post the causes of my problems and the fix. Maybe it will be of help to someone.
After I traced as many grounds that I could find (Found 12 in all) and unbolted and rebolted anything electrical that I could. I noticed while i had the battery out that the fuse box cover next to the battery looked a bit like it might have been sticking up just a hair. Upon inspection I found that the 2 60 amp fuses were loose as well as the ecm fuse. I pushed them in a little better then 1/4 inch. Fired the car up and had the same problem so I went a bit farther trying to remove the red cover asI could see a hot spot on the terminal. The red cap would not come off due to the red lid having been so hot it welded itself to the fuse box. After an hour of playing with it I was able to work it off. The Lug was rusted and burnt. (Plastic had melted on the lug from the lid)
I took some sandpaper and cleaned the lug and the 2 metal transfer contacts that charge the fuse box. I put it all back together and my oil pressure reads 40 to 60lbs where it was reading 20 to 30. Battery gauge shows a steady 14 volts it was showing 10. the A/C switches are all now working as well as the stereo lights and windows. And No more back firing and no more all dummy lights coming on.

I have drove the car for 45 minutes and so far so good before I could not even get out of the drive way.

Now the question is why this happened would you pull these fuses to change the opti-spark? I have never pulled these fuses only the inside fuses. Why did the lug and box get so hot? Could this be from the fuses not making full contact and sparking?

I wanted to thank everyone that has offered their help.

 

Congratulations on finding the source of your problems. This is great news, and thanks for sharing the info with us.

I'd say that most likely the coincidence of this with the Opti swap was just that -- a coincidence.

Be well,

SJW

 

jmn....that is great that you figured it out. That is good troubleshooting!

I have a PDF of the ground diagrams for a 92 if you would would still like them. I am sorry I didn'r offer them when you were having your problem, I got sidetracked from this thread.

If you want the diagrams e-mail me and I will send them back to you.

 

Thanks and I understand getting pulled away. I will tell you now that that problem has been fixed I am very suprised on how much stronger that the car runs. It will flat plant you in the seat. Let alone the big changes in everything working once again.