takeittothemax

I am currently working on my 1999 Corvette. To say it is being a pain in my butt is putting it mildly. It's always electrical as those that know know it well. It all started with my getting ready for spring which is a yearly ritual especially in Nova Scotia Canada I installed a set of HID lights last year and periodically they would fail to ignite and after some research I found that I need it to wiring harness with the Transformer. I hope them all up beautifully worked like a charm. Installed a new set of Michelin Pilot Tires and I reset all the TPMS. 3 years ago I installed an aftermarket stereo system that works fine other than the fact every time I turn the car off the stereo had to reload itself due to the fact that it is more computer than stereo so this year I decided to install a toggle switch so that every time I turned the car off it didn't turn stereo off. Everything seemed great finally getting rid of all the headaches that annoyed me with the car. I lowered the car down on the tires. When I start up the car I started to notice a few things. When I started the car the reverse light stayed on. If the shifter was in reverse it is a manual transmission by the way then the fuel pump would continue to run. If I started the car in reverse and let the clutch out the engine would die. I have been working at this for a few days. My first thought was the fuel pump was not running properly due to a dirty filter so I installed a new filter and the old filter did need replacing. The four wires going to the fuel pump the black blue and two Gray are very confusing . I did a voltage test on the blue wire which I think is the fuel level indicator and in start position I got 4.97 volt and in the running position I got 1.07 volts. I tested the grey wire and I didn't get any voltage on that one. Nor the other grey one.. I even took the fuel pump out to bench test it..it semed fine other than the fact when I installed it the fuel level doesn't work. I could really really use some advice.. after I realized that there were problems i unhooked the hid light as well as anything else that I did this year trying to pinpoint what was wrong. After I put the fuel pump back in tonight and tried it that's when I realized that the fuel level gauge does not work I'm not sure if it got pinched going into the tank that is the least of my concern at the moment. I also noticed that there is no communication between any of the modules in the computer system in the dash. Everything from my shocks are inoperable and when I tried to check to see if they were any codes every module is not communicating. This has me stumped and I am very mechanically minded
thanks for your time fingers crossed have a nice evening
Max

gaspeddleZ07

Blockhouse! I grew up in Bridgewater LOL!

With the number of issues you've raised, this doesn't sound like an easy on-line diagnostic so you may not get very many responses. As with anything electronic, my advice is run a diagnostic to see if any codes are being triggered, then use the "seek and destroy" approach by taking it all back to original and diagnosing one issue at a time. It may be faster / cheaper to find a decent shop and have them diagnose it as the volt meter will only take you so far...

takeittothemax

There are no codes .it isnt communicating with the computer system...i would love to take it to a decent repair shop however i dont have any faith in the local ones.i was just hoping for some advise .
I love the car .I have worked it well for 4 yrs now..i know it quite well .in fact i have bern the only one.no roughness appreciated there lol.
Thanks for the reply
Have a nice day
Max

Black 03 Z06

OP, think you will have better luck if you post this in the C5 section (if you have not already). Not that there is not a lot of experience in the Canadian section there is but there are some guys in the C5 section that are extremely good at electrical diagnosis.

Good luck.

takeittothemax

I just did that thanks again for the reply hopefully I will find something out even if I can find out what the four colored wires are for to the fuel pump it says in the schematic that they should be 12 volts by way of the gray thanks again have a nice day

The boss

It is not that easy to help with a problem like this from a distance. On your connector, if you look closely, you should see small letters to identify the wires, wire A is grey is a 12v from the fuel pump relay to feed the pump, B is gray and is a ground for the fuel tank pressure sensor, C is the blue that feed 5V from the from the PCM for the fuel tank pressure sensor and D is the black wire use ground the pump.

When I have to dig a problem that affect so many different circuit, I generaly try to find something in common. On these cars Ground are critical, I would first check all fuses (even the non related ones) and all grounds, unscrew and clean them all.

If you need, send me a email addess and I will send you wiring diagram. I can do this a the shop in spare time so it may take a day or two. Computer data line wiring are not for the faint of heart

Dont forget to give me all the info about the car, coupe, vert, engine...


Good luck

Stephane

takeittothemax

First of all I would like to say what an honor it is to have you on board. I'm not one to get easily frustrated but this is taking it to a whole new level. I am very mechanically minded and I guess that's what makes this so hard.
There is 13.54 volts across the battery and there is 12.75 volts across the battery with the key on after 2 minutes. I tried to fix my fog lights today and then I noticed that the fuses and relays were all good however there was no power on those circuits. In fact there for circuits in total that did not light up the test light. The other Fuses are as follows

#6--RRFOGLP
#1--APPROACH
#9--HDHBMR
#11--HORN --- even though that one works.
These are fuses that are in the engine compartment fuse box.
When I open up my car doors with the key in it was no longer any chimes nor the courtesy light coming on.. even though if I close the door and the key is in the ignition there is constant Chiming from the Dash telling me of all the DTCS.. such as no modules are able to communicate. Shocks in operable. Reduce engine speed. Check tire pressure . I can't clear any of these. I can no longer activate my FOB.
I don't understand what the shifter has to do with the fuel pump. It continuously runs if the shifter is in reverse none of this makes any sense. I don't understand why I don't have power at the fuse box. My car is in Immaculate condition. It is never seen ice or snow much less salt always kept in a garage. I've checked all the grounding points they are fine. There's always been something to raise its head with this car and regards to electrical however I've always managed to get it worked out. Now everytime I walk to where's my car I feel sick. I really do appreciate your help in this matter have a nice evening
Max

Maxcbishop@gmail.com

1999 regular corvette with the following mods
Vented disc brakes. Parrot smart receiver which is actually a complete onboard computer that holds 20,000 songs by way of memory cards and flash drives and totally voice activated Bye song or album. It is worth Googling it to see why the piece of Machinery this is too bad they don't make any new ones. MagnaFlow exhaust. Fixed European lights. Z23 hood. Rear spoiler. HID lights both head and fog lights.steinjager front and rear sway bars plus adjustable sway bar links. Short throw shifter. Skip shift attachment. Spider rims. Curb alert. Small grills in the front of the air intake. Roller wheels on front frame to avoid scraping
The majority of the time this car work great
Once again I really appreciate your help in this matter have a good evening
Max

lionelhutz

Fuel gauge is over the bus and so are the codes. So, no comms means neither works.

Try disconnecting the connectors at the seats. If that doesn't bring back the comms then pull the accordions out of the doors and the harness out of the door frame. Unplug the connector you find there.

As for the fuel pump - you couldn't figure out the connector wiring when you had it on the bench?

takeittothemax

Thank you for the reply I will try some of those items. Yes I managed to figure out the power feed afterwards needless to say my head is not in a good space LOL I'm still trying to understand why a vehicle needs to be so complicated. Once again thanks for the input have a nice day

The boss

HI Max. Check your email, I will send you the power distribution wiring diagram for your car. It have 4 pages. You can see on the first page top left, there arer fuse link that supply the fuse block under the hood, you may start there. These are the complete 12v distribution for complete car.

Electrical problems are not always that bad, take your time and stay patient, you will win

Good luck

Stephane

Cdn Z06 Mike

I suck at electrical to be honest as its my weakness on cars. I know the C5's are notorious for BCM failures or intermittent failures? Hope you get this sorted out as it would leave me sleepless.