Advice on a couple of C5 Issues

[phn]

Hi there, I joined CCC a few days ago as I'm looking for a C5. I did test drive a very nice one today however it had a couple of strange issues:

1.) The climate control temperature display initially had no set temperature display at all (only the fan speed) but then after a few minutes the set temperature numbers flickered into life and it was fine after this? Is this a sign of the climate control display being on the way out, and is this a costly fix?
2.) The headlights only popped up and illuminated approx 1 in every 4 times that you twisted the stalk to the on position. It was weird - occasionally it worked fine, but most of the time not. I was wondering if this is a dodgy stalk or is there some special procedure I am unaware of to get the headlights to work? (When they did pop up they both worked quickly with no unusual noises).

Finally the car was on standard wheels front and rear but probably needs new tyres. What would be the approx cost of a replacement set of good quality tyres?

Many thanks!

 

[Pitre]

Mine had the climate control display problem, it's quite common, unfortunately.
If you're handy with a soldering iron it's a simple fix here:-

 

[FIVE RED]

Although I've not had the problem with the climate control display, this is a fairly common problem which is resolved by re-soldering the connections on the back of the display, not a tricky job if you're a bit handy.
Re the headlamps - there is another common problem where the plastic gears strip teeth & refuse to go all of the way up. Each headlamp can be raised manually & you'd be able to tell if the gears are stripped while trying to raise them. If this is the case then again it isn't too difficult a job if you're a bit handy. I wrote an article on this in an issue of Vette News some time ago so you could look this up if you need to.
Either way if the C5 you looked at is a beauty then you have some bargaining leverage when negotiating the vehicle cost.

 

[Pitre]

Five Red's C5 Headlamp gear replacement article available for download for members only from HERE

 

[phn]

Mine had the climate control display problem, it's quite common, unfortunately.
If you're handy with a soldering iron it's a simple fix here:-

Thanks - that doesn't look too difficult!

 

[phn]

Although I've not had the problem with the climate control display, this is a fairly common problem which is resolved by re-soldering the connections on the back of the display, not a tricky job if you're a bit handy.
Re the headlamps - there is another common problem where the plastic gears strip teeth & refuse to go all of the way up. Each headlamp can be raised manually & you'd be able to tell if the gears are stripped while trying to raise them. If this is the case then again it isn't too difficult a job if you're a bit handy. I wrote an article on this in an issue of Vette News some time ago so you could look this up if you need to.
Either way if the C5 you looked at is a beauty then you have some bargaining leverage when negotiating the vehicle cost.

The thing is the headlamps worked perfectly sometimes when the switch was turned, but not other times. I would have thought if the gears were stripped then they would never work properly? Anyhow the vendor just told me that this could be something to do with twilight sentinel being activated so maybe this is the cause?

 

[Stingray]

I had to do the DIY soldering fix on my climate control panel. Worked out fine.

Although my pop-up headlamps never gave any trouble I'm aware of the "new gears" fix. Seems to be pretty standard stuff.

C5 - fantastic cars.

 

[Invetterate]

Welcome!
Re tyres, I have Michelin Pilot Sports on my C5 and they are streets [literally] ahead of anything else I have had in the 20 years I have owned it. The latest version is the PS5 and these are available [fitted price] of around £170 each for the front and £245 each for the rear. Decent tyres can be had for less [eg Toyo Proxes at £170ish for rears] but don't go for anything you haven't heard of before! A good tyre makes all the difference.

 

[Pitre]

Michelin are by all accounts the best you can get, but obviously expensive. I have Kumho Ecsta PS91's on my C5 and they are pretty quiet and quite grippy too, although in fairness I rarely drive it in extreme conditions and I don't drive my car 'hard'. You also have to decide whether you want runflats of course.
You pays your money and takes your choice...

 

[teamzr1]

Hi there, I joined CCC a few days ago as I'm looking for a C5. I did test drive a very nice one today however it had a couple of strange issues:

1.) The climate control temperature display initially had no set temperature display at all (only the fan speed) but then after a few minutes the set temperature numbers flickered into life and it was fine after this? Is this a sign of the climate control display being on the way out, and is this a costly fix?
2.) The headlights only popped up and illuminated approx 1 in every 4 times that you twisted the stalk to the on position. It was weird - occasionally it worked fine, but most of the time not. I was wondering if this is a dodgy stalk or is there some special procedure I am unaware of to get the headlights to work? (When they did pop up they both worked quickly with no unusual noises).

Finally the car was on standard wheels front and rear but probably needs new tyres. What would be the approx cost of a replacement set of good quality tyres?

Many thanks!

As noted, most cases the HVAC head unit issues is due to cracked solder joints
Please use the correct soldering iron and practice, as the one shown on that video was not done very well

Here is one I repaired, I set up what was needed to make the HVAC head functional off board and can see how dim the screen contents were
Then soldering the resister packs and then testing afterward and can see how much brighter contents is even with daylight



As to tire's example, I have used the BFG G-Force series which has 45,000 mile warranty
The A/S is the all-season tires




Summer or more designed for best performance is what I use for my C5 for many years for track and street
Has very good traction



As to headlights, there is a large adjusting knob, make several tuns on it when car is off
Notice if the headlight doors open smoothly or want to drop or get stuck would say if you need to replace
the gears using the better metal ones

 

[phn]

Thanks to everyone for all the further information and detailed posts - very much appreciated!

Really impressed with how friendly and helpful everyone is in this club.

 

[C5Steve]

I've also repaired a HVAC display, will need to do my new one at some point as it's on it's way out. One thing I found useful is if you're going to do it you do have to be careful not to overheat the joints as you can burn out the resistors (If you're a soldering novice like me that's a concern). I bought something called a Cold Soldering Iron. I found it a lot easier to use and ensure I didn't bugger up the joints, also the design of the tip makes it easier to re-do the connections on the PCB. Loads of vids on Youtube, I'd give it a go yourself.

In regards to tyres I think you've had good advice on the Michelins, if you can I'd go with those. I'm running Pirelli's P-Zero's now and haven't had an issue but will be switching to Michelin's when the time comes.

 

[plastic orange]

My repair of my HVAC display took 1 hour start to finish, so i would say it's not a deal breaker. Since I got my C5 2 years ago, I've had all the usual issues - EBCM - easy fix, HVAC, easy fix, Steering column position sensor - reasonably straightforward made a bit more difficult by the way the alarm system was crudely connected for UK market. Prior to me purchasing car (2001 model with only 32k on the clock) it had a recent harmonic balancer with all the ancilleries, new disc/pads, new bilstein shocks, drop links. Most faults come with age I'd suggest, so perhaps buying a low mileage one was false economy. Most annoying issue is keeping battery charged unless used regularly.

Pete

 

[phn]

I've also repaired a HVAC display, will need to do my new one at some point as it's on it's way out. One thing I found useful is if you're going to do it you do have to be careful not to overheat the joints as you can burn out the resistors (If you're a soldering novice like me that's a concern). I bought something called a Cold Soldering Iron. I found it a lot easier to use and ensure I didn't bugger up the joints, also the design of the tip makes it easier to re-do the connections on the PCB. Loads of vids on Youtube, I'd give it a go yourself.

In regards to tyres I think you've had good advice on the Michelins, if you can I'd go with those. I'm running Pirelli's P-Zero's now and haven't had an issue but will be switching to Michelin's when the time comes.

Wow - I didn't even know there was such a thing as a cold soldering iron!

 

[phn]

Most annoying issue is keeping battery charged unless used regularly.

How often did you need to charge up the battery when not in use? Would a battery isolator be a solution?

 

[FIVE RED]

The C5 has a well documented parasitic battery drain. In my experience if you leave the car for 3 weeks you'll end up with a flat battery, 2 weeks you should be ok. Coupling up a battery maintainer is no big deal if you know you'll not be using the car for a while. I've been doing this since I bought the Optima Red Top some 13 years ago, still going strong .

 

[teamzr1]

The newer the Corvettes design is, the more controllers it has
C8s now have over 30 controllers on 7 different on board networks
Many of them store functions, settings, etc in a temp memory and when voltage of the battery is reduced like under 12.4 volts the controllers
cannot work correctly, or lower voltage than that can cause all the content in stored memory to get lost

My 1999 C5 which is rarely driven is connected to a battery tender for like 20 years, in cold seasons like today where high weather temp here is like 12 F deg, colder battery is the lower the voltage is
The tender not only keeps a fully charged battery at 12.7 volts but also by charging keeps the battery internals warmer in cold weather

You can use a tender that plugs onto A/C electrical outlet, or I have a 1993 Caddy that stays outside and uses a solar power tender and even today
with the car not used for 5 days using a remote, battery monitor shows fully charged even when no sunlight as solar even collects with indirect light

You can hard-wire from battery and run the 2 wires with a connector outside the car so do not even have to open the hood to plug/unplug your tender

By doing this the 15-year-old battery in my C5 still functions well and at the price of new batteries today a tender really saves money long term

 

[plastic orange]

How often did you need to charge up the battery when not in use? Would a battery isolator be a solution?

In this weather the car doesn't get used much, so i just charge it every 10 days. Car sits outside, so don't want to run cables to be left in place. A battery isolator would be ok if car didn't have pcm, bcm etc powered constantly. I believe every time they are powered down there is a relearning process when started, so I just charge it as mentioned. I have an LS powered Morris Minor and it's powered all the time with no parasitic drain at all and no issues.

Pete

 

[Stingray]

You'll know if you have a weak battery in C5. DIC goes crazy. Things like defaulting into kmh instead of mph or spurious ABS alerts after starting. It's caused by excessive voltage drop while cranking. The starter needs "amps" and the electronics need "volts". When the starter draws high current from a weak battery it might start the car but voltage could drop to 8v or 9v for a few seconds and everything goes crazy.

 

[C5Steve]

In this weather the car doesn't get used much, so i just charge it every 10 days. Car sits outside, so don't want to run cables to be left in place. A battery isolator would be ok if car didn't have pcm, bcm etc powered constantly. I believe every time they are powered down there is a relearning process when started, so I just charge it as mentioned. I have an LS powered Morris Minor and it's powered all the time with no parasitic drain at all and no issues.

Pete

You have a what now? Have we seen pics of this beast??