When car is driving down the road it will just shut off. Usually it will restart but it has recently failed to start. I have noticed that the radio will not get any stations and the speedometer doesn't work and when it is going to act up it will the speedometer go all the way up and when I put it in drive go to 79 kmh and then drop to zero when I start driving. After a km or so it'll shut down. I also have had the temp light come on with the buzzer and the gauges both digital and analog both shows the car is cool since I only drove a km or two. Changed coil and ICM and does start better but still acts up. And service engine light comes on and when I restart it it'* gone until the next time. It also seems like the radio works when it'* hot outside and the car has sat in the sun all day. What is going on. I'm starting to get frustrated. I had it to garaged and looked things over and don't understand what is wrong. Everything checks out ok at garage and then acts up after I leave. Any help is appreciated

Is this a car of some sort?

Sounds like something electrical to me. Probably worth checking major electrical connections including grounds.

Is this the 1990 Oldsmobile Delta 88 that you have listed in your profile?

How many miles (or kms) on it?

How many miles have you owned it?

How old is the battery?

Has it had any recent trauma (accident, abuse, major repair, etc.) ?

When you said you had it garaged, do you mean that you took it to a professional mechanic or that you looked it over while it was in a garage?

1990 Oldsmobile Delta 88
I have had issues with this car and I have had it in to my mechanic a few times and everytime time he said he thinks that it'* fixed and is working well. Soon after it shuts off starts sputtering . Lack of power and when I read the code it says code 42 every time. It does start right back up after pulling over,but if it is rolling on highway it starts but acts bad. If you wait a few seconds it'* runs fine again and in my opinion when you hit bumps it acts up . I have replaced the ICM,coil,cam sensor and tried to replace new crank sensor but car would not start so they reinstalled the old crank sensor and it ran great for a while. The list of issues are as follows. The radio stopped working. It'll turn on but no radio stations and when you hit the brake pedal you can hear a click/ snap in the speakers and when you use the signal lights you also hear this snap/click through the speakers. But when you flash the high beam headlights it doesn't do that but if you turn them on and off you do. What is wrong with this car. I have tried to check wires ,grounds and everything else I can think of. Is it the computer? A ground or wire going to the dash or tail lights? Any help is greatly appreciated and I need it. It'* awful paying insurance etc for a lawn ornament that'* in such great shape and has always been looked after. I'll take all information that anyone will share. Thanks

Yes it has been to a garage/license mechanic and I can not find what is wrong with it. I have taken the dash apart twice and it'* so hard to see any wires under the dash by radio and under the speedometer area.i have looked in the trunk at the wires to under the hood. I have been checking everything I can and I can't find anything wrong. Does the ECM have anything to do with the 📻 and speedometer. Both are acting up. Radio stations will not come in and you hear a snap click when you hit the brake pedal,use signal lights or turn on the headlights or turn them off . I don't understand why? Ground? Where would it be or is it a ECM. Starts fine but it will act up with a half a km or less or shut off and it will start again but acts bad. No power etc. I'll take any help and information on what or where to check. Thanks 🙏

I meant to say speedometer goes all the ways up and will stay there for a few a and then drop back to 80km/h and when I start driving it'll drop to 0 and will jump when I use the signal lights. Then sometimes it will jump every now and then when driving and then start working fine. But you never know what you will get when you get in to drive it. Know the radio stations will not come in. You get no stations and you can hear a click snap when you touch the brake pedal or when you use the signal lights it does this also . The snap click is through the speakers for the radio. I have looked at alot of wires etc and grounds and can't find anything. Only when it shuts off I get a code 42 and code 12. Please help

Sorted some stuff out. Post #5 was originally posted in a separate thread. Post #6 was added to this 20 year old thread for some reason.

Moved Post #5 from the other thread to here. Moved Post #6 from the 20 year old thread to here.

There are wires crossed somewhere. I think some exploration with a volt meter and a test light is in order. All the noises you described coming through the speakers tell me that likely a ground wire is improperly in contact with some number of radio-related wires. Could be something besides a ground wire crossed. Maybe it is a disconnected ground wire and other systems are finding a ground path through radio-related wires. Maybe a radio-related wire has chafed on some grounded metal and is creating a new circuit path. I can't tell from here.

As a first step, remove the radio and see if everything continues to malfunction the same way.

Also:

Code 12 is [no engine RPM signal]

Code 42 is [ignition bypass circuit error]

It has around 260 000 km on it. No accidents and it was looked at by a dealership garage. I also have been looking at it at home as well. I am an electrician and I also believe that it'* a electrical wire/ ground somewhere in the dash but I can't find how a person suppose to get at the wires behind the stereo etc. I removed all the dash and it has metal etc still on the way. Any help information is greatly appreciated. And where would you start at looking at wires and how can I access them. Thanks

As you pull the radio out, the wiring on the back of it is long enough to be able to disconnect it while the radio is out.

Also: