90 ZR1 not charging

[Paddy_SP]

Hi All - This is my first post, and I was hoping it would be under happier circumstances...

Back in the late 80's, I used to work as a test engineer at a place called the British Internal Combustion Engine Research Institute. One day Lotus turned up with a protype LT5 engine for us to do some flywheel explosion testing on. Basically, for litigation purposes, GM wanted to demonstrate that if someone who wasn't used to driving a manual-shift car drove a ZR1 with their foot half-on the clutch pedal, no matter how badly they abused the car, the flywheel wouldn't overheat, crack and break up. One day soon I'll write a detailed version of this, should anyone be interested. Anyway - I loved the LT5 so much that I said that one day, I would own one myself. That day was three days ago!

This afternoon I had to go to a meeting at our local university, and took my lovely 'new' '90 ZR1. It's an ex-Bill Streeter car, if that means anything to anyone. When I jumped in to drive home, the battery warning light was on, and the voltmeter was only showing about 12 volts. On the journey there, it was significantly higher. By the time I got home, it was down to about 11.5v. I've just tested it with a meter, and it is not charging - at all. The only thing I can think of is that I went over a large rise in the road, and the car landed with a heck of a thump - maybe this dislodged a connector?

Before I go pulling my new pride and joy apart, I'd really appreciate it if anyone here would be kind enough to advise me where to start looking. I worked as a race-car engineer for many years, so I'm not exactly helpless, but if this is a known issue, I'd rather benefit from the forum's experience and go straight to it!

[TN90-ZR1]

First of all Congratulations on your purchase, I'm sure it's a thrill ...I know it was for me.
On to business. I have a 90 as well, and had the exact same issue about two months ago. Turned out to be slight corrision inside the negitive connection on the battery itself. Cleaned it out with a small brush and haven't had a problem since. Best of luck and enjoy your new car.

[Paddy_SP]

Many thanks for your reply and kind sentiments!

As to the problem - I checked the alternator's output this morning, and it was zero. I pulled it off and checked the rectifier pack, and two of the diodes were dead. I've just driven for two hours to see if I could get some replacements, but was not successful. The store I went to said that they will have a new unit for me on Monday - I also ordered a new diode pack so that I can rebuild the original unit as a spare. Sadly, this means that I won't be able to enjoy the nice weather that has been forecast for the weekend - over here we've had rain for months...

[TN90-ZR1]

=D> Glad to hear you found the problem so quickly, but sorry to hear that you won't have them in time to enjoy the w/e weather, they'll be others my friend. Enjoy the new wheels. Where abouts in SW England do you live ??

[Paddy_SP]

Originally Posted by TN90-ZR1

=D> Glad to hear you found the problem so quickly, but sorry to hear that you won't have them in time to enjoy the w/e weather, they'll be others my friend. Enjoy the new wheels. Where abouts in SW England do you live ??

I'm in rural Devon, in south-west England. The roads here are not much wider than the car in places, and often have twelve-foot hedges either side. If this isn't bad enough, they're usually populated by maniac milk-tanker drivers and in-bred farmers in 10-ton tractors, so it can be somewhat nerve-wracking to travel along them when you're driving something that you want to keep immaculate...

I should have said earlier that the car has done 32,000 miles from new and has never seen rain, so it's unusually good as far as most cars over here go!

[Paddy_SP]

I'm a happy man - the new alternator went on without too much hassle this afternoon, and the 'Z' is now charging again!

[QB93Z]

Well Done! Glad to hear that you got your ZR-1 running again. I would like to hear more about the LT5 testing.
Thanks, Jim

[Corvette95]

Let us know if the new alternator fixed the problem. Also would like to know brand and part number you installed and if you are happy with it. As fas as flywheel testing goes, sounds like a GREAT article for out Heart of the Beast newsletter..especially if you can dig up some pictures. Email me or PM if you are interested in writing an article for us, I assume your a registry member already

Thanks!
Corvette95
Chris Gilliand
Race Director ZR1NetRegistry.com

[Paddy_SP]

Jim - Many thanks for your kind comments!

Originally Posted by Corvette95

Let us know if the new alternator fixed the problem. Also would like to know brand and part number you installed and if you are happy with it.

The new alternator did fix the problem, however, when it arrived, there was not a sign of a maker's name, number, or anything on it - even the instruction sheet had no clues as to who made it. I have to conclude that it's a cheap Chinese item, so will be keeping a close eye on it. I have also ordered a new rectifier set for the original alternator, so will rebuild that and keep it ready...

Originally Posted by Corvette95

As far as flywheel testing goes, sounds like a GREAT article for out Heart of the Beast newsletter..especially if you can dig up some pictures. Email me or PM if you are interested in writing an article for us, I assume your a registry member already

Thanks!
Corvette95
Chris Gilliand
Race Director ZR1NetRegistry.com

Unfortunately, I don't have any photos of the engine under test... I would, however, be happy to write an article for you - I work as an author in my 'spare' time. This has its downsides though, as I have two books to complete by the end of October, on top of my day job (anti-terrorist blast-mitigation textiles). Consequently, I'm afraid it'll be a few weeks before I get a chance to sort the article for you!

I'm not a registry member yet...

[Corvette95]

first of all congrats on getting the beast fixed, second JOIN the registry, third, shoot me an email at corvette95@charter.net and we will discuss you writing an article - WHEN you have the time!
thanks!
Chris

Race Director ZR1NetRegistry.com