New Gremlin Just Popped Up

[Irish Pride]

I'm going to start off this thread by saying that this Blue 95 has been an electrical nightmare since the day I bought it. I thought that I had everything corrected and now this...

I have a thought about what the problem might be but want to see what others have to say. The car starts and drives. It drives great. Just put 1100 miles on it going to the convention and back. Now I have some sort of short in the dash it seems. As the car warms up, the temp gauge will continually rise until the needle is almost pointing straight up. Well past the Hot mark and into what should be boiling over stage. The car is not running hot. I have aftermarket gauge and it stays right around 190 while idling. While this is happening the fans are running constantly. If i have the headlights on the dash lights will gradually get dimmer until you can barely see they are on. With all this happening, if I turn on the wipers the dash lights get bright again and the temp gauge will move. Turn the wipers off and the dash lights start going dim and the gauge needle stays pegged straight up. Also, when I turn the wipers on the EATC display will flicker if its off and if its on the display will flicker and the EATC will cut out the entire time the wipers are on. Turn the wipers off and the EATC will come back on. All of these things appear to be connected, the temp gauge, dash lights, wipers, and EATC. Everything else seems to be working fine. I can drive the car as long as I dont need AC and wipers at the same time.

Thoughts?

 

[Michelle]

Did mice get to this car at some point? Or has it had an aftermarket alarm system?

I give credit to those who can overcome electrical issues. I look at wiring diagrams and say NOPE!

 

[luigisho]

Good constant power at battery and alt? First thing that comes to mind is the sliding dimmer switch but I'm not sure I've seen it do much more than lights and gauges. How is the rectangular ignition switch under the dash area? I hope it's not a spaghetti short somewhere.

 

[Irish Pride]

Good constant power at battery and alt? First thing that comes to mind is the sliding dimmer switch but I'm not sure I've seen it do much more than lights and gauges. How is the rectangular ignition switch under the dash area? I hope it's not a spaghetti short somewhere.

Battery is solid and alternator is putting out good juice. It has a voltage gauge and stays just over 14 at all times. Voltage does not move while these things are happening.

 

[rubydist]

The temp gauge seems to be seeing a short - iirc the temp sender resistance goes down as the coolant temp goes up, so what you are reporting indicates the gauge sees a very low resistance on the signal wire.

If the cooling fans are running all the time, that is a separate issue, because the coolant temp sensor that the pcm looks at to control the fans is a different device than the one the gauge looks at.

The instrument lights seem to have a bad ground - as it warms up the resistance goes up so the amount of light given off gets dimmer.

The combination of stuff you describe with the wipers and eatc suggests the shorts and /or ground issues are in the harness in the dash somewhere. There are a bunch of wires in there so it will likely not be fun to find.

 

[SHOCH]

I think the only time I’ve ever been able to help anybody on this forum in 15 years because everyone is so fast to help, was telling them that they should smell their headlight switch because so many wires go through there and they did and it stunk and they changed it and everything was fine.
Shot in the dark.

 

[Irish Pride]

The temp gauge seems to be seeing a short - iirc the temp sender resistance goes down as the coolant temp goes up, so what you are reporting indicates the gauge sees a very low resistance on the signal wire.

If the cooling fans are running all the time, that is a separate issue, because the coolant temp sensor that the pcm looks at to control the fans is a different device than the one the gauge looks at.

The instrument lights seem to have a bad ground - as it warms up the resistance goes up so the amount of light given off gets dimmer.

The combination of stuff you describe with the wipers and eatc suggests the shorts and /or ground issues are in the harness in the dash somewhere. There are a bunch of wires in there so it will likely not be fun to find.

Luckily, I was able to find the problem and you were pretty much spot on. It was completely my fault I guess. The day before all this started happening I removed the carbon fiber filter can and cone filter from the car and installed the stock airbox. Right next to the airbox on the inner fender wall are 4 separate grounds that all attach with the same screw. I guess it was already loose and I must have rubbed against it while installing the box and caused a break in the connection. Tightened that ground and now everything is back to normal.

 

[Greg Corcoran]

Luckily, I was able to find the problem and you were pretty much spot on. <<snip>> Right next to the airbox on the inner fender wall are 4 separate grounds that all attach with the same screw. I guess it was already loose and I must have rubbed against it while installing the box and caused a break in the connection. Tightened that ground and now everything is back to normal.

I was also thinking you lost a ground, but I NEVER would have looked there...