Hello all.

I am new here and really need some help.

First it's a 98 C5.

All the lights are out!

The speedo won't light when the headlights are on. All the other lights work, such as the oil light, air bag, digital display, ect but none of the gauges work?
The fog lamps won't come on when the headlights are on but they do come on when you press unlock on the key fog. WTF?

The Drivers seat only works a little. The big bar allows you to move forward, back, up and down but none of the back lubar buttons or the side lubar buttons work.

I hope it is bad relay switches. All the fuses in the car are good.

WTF is going on with this car?

Please help!

 

do you have any fault stored in the instrument cluster[ipc]or any other systems?

 

I don't belive so

How can I reset it to default?

(I just got the car so all this is new to me)

 

Are there any mods to the car like Euro tail lights or flashing 3rd brake light? These kinds of mods use aftermarket wiring harnesses that can go bad and give the kind of symtoms you're describing.

 

This sounds like a classic floating ground fault.

Other than having the factory service manual, I don't know of any
good way to diagnose this problem. I suppose you could scour the
car looking for broken ground straps, and hope to get lucky. One
prime spot to check is under the passenger footwell conceal panel.

If you do have the factory service manual, leaf through the electrical
section looking for the location of the various ground points, then
make sure they are there, clean, and tight.

Electricity sure does funny things when you don't give it a well-defined
flow path...

 

In the tool bar at the top of this page is an "Other" icon. Under that icon is "Tech Tips" and under Tech Tips is "C5".

The following link is one of the "C5" tech tips. This explains how to extract the Instrument Panel Cluster (IPC) Diagnostic Trouble Codes (DTC).

Check and see what codes if any are set.


https://www.corvetteforum.com/techti...D=26&TopicID=1

 

As other have stated it may be a problem with a ground. Also check for a good connection at the Instrument Panel Cluster.

Given the complexity of the wiring, access to a Service Manual would be a great help.

 

I am guessing the headlights are not working either? I have had a few blow a fuse in the panel on the right side floor, I cant remember the fuse off the top of my head and I dont have a Vette right here to look at, but its not a fuse that you would think is linked to it all. So check all the fuses in the floor fuse panel.

 

Modified

I also have a 98 Coupe. I have had more than my fair share of electrical problems!!!
I have scowered the service manuals, used the help of the forum and gone as far as to personally talk to the GM Service Reps at Bowling Green KY.
C5's are a very COMPLEX electrical nightmare! Here are some of the things that I have learned through the school of HARD KNOCKS!

C5's use central ground points to ground circuits to the chassis. There are 13 of them! They are KNOWN weak points and will go bad sooner or later! Most of them use a buss bar with "V" points that the ground wires are pushed into! Kind of like the telephone junction boxes.
If the connectors are subjected to moisture, the mechanical (NOT SOLDERED) joint can corrode and cause problems! Some ground wires may not be pushed into the "V" groves all the way and cause bad grounds! An example of a "Ground Lug" can be found on top of the drivers OR passengers frame rail behind the head light assembly and inboard of the coolant recovery tank!
You will see numerous black wires going into a plug and the plug will be fastened to a stud using a nut!

You will learn that when you have numerous unrelated electrical problems, you will have to take them on ONE AT A TIME!

Here a couple of things that will create costly electrical issues!!

AC/Heater box drain will clog up and drip/pour water into the passengers foot well! The Body Control Module $230 is located there! If that gets wet,, STAND BY!! You will have all kinds of weird electrical issues!

The windshield cowl drains (3) will clog up and the windshield wiper motor and electronic control module will get submerged in water and the wipers will take on a mind of their own and soon after that FAIL!

Battery (stock AC delco) will leak and drip battery acid on to the PCM and TAC module that is located below the battery tray. You will loose the AC/Heat vent positioning vacuum supply as a first symptom (acid eats up the plastic vacuum line) and then you will have some serious electrical problems shortly there after.


You need to become ONE with the Drivers Information Console (DIC) and when you have problems, see what codes are presend and figure out what they mean!
If you can post the codes, you will get more help a lot faster!

Check out this site: www.stengel.net/diccodes.htm

I recommend that you review the codes by using the following link:
http://www.stengel.net/diccodes.htm



Turn the key to the ON position, but don't start the engine. Clear any present messages by pressing the RESET button. Hold the OPTIONS button down, and press the FUEL button 4 times. This will get you into the CODES section of the DIC. The computer will automatically display all the codes your car has created. It will cycle through each code every 3 seconds. Any code that ends in H is a history code (something that has occured in the past) but is fine now. Once the computer has finished going through all of it's codes, press RESET to enter Manual Configuration mode. It should start with a module and show "NO CODES" or "# CODES".

To optionally reset the codes once in manual mode, press and hold RESET until it displays "NO CODES". Press OPTIONS to go to the next module. Repeat the steps in this paragraph until you have reset the codes in all the computer modules. NOTE !! Only reset the codes IF you want to - it is NOT necessary to do this.

Please post the codes and we will be happy to help you solve your problems. I have a 98 service manual and will be glad to help you sort this MESS out!

Bill C

 

Thanks for all the help. I will give it all a try.

 

Please let us know how you make out!

BC

 

Bill... that was truely a great post and one of the reasons this forum is such a valuable resource for Corvette owners.

Don

 

This is one of the BEST forums out there!!! I really enjoy helping people fix their issues! It gets me into the service manual and even I learn things! I see issues that I have not had to deal with on my cars and if I ever do, I'm better prepared to kick *** and fix it!!

BC

 

Thanks for all the help.

I had to fly to Florida and now I am back in New Mexico.

The cars steering column totaly locked on my wife the other night. I think this is on of the major recalls on the C5. Anyway, she had to call a flat bed to come and get the car to take it to the local dealer to have it repaired. It is now in the hands of the used car salesman to pay for all the repairs. Under NM law we have an Implemented Warrenty of 15 days to have Major repairs fixed. Well this is pretty major and after only 3 days of having the car I wonder if I either got a lemon or it having a Vette worth having these kinds of problems? The car is a 98 so I do take that into consideration. It's kind of odd that all these problems occur after a few days of owning it. I test drove the hell out of the car, then drove it 200 miles home from the dealership. WTF this hasn't been a good week for me of the wife. I need to go have a few

 

Well,, I do not know what the dealer is going to do for you! I would recommend getting a Column Lock Bypass, installing it and then you will NEVER have to worry about "THAT" problem again! Its an easy fix!

Please let us know how you make out!

Bill

 

It is madated under New Mexico law.