Hi all,
Got a problem with my 1990 C2, collected from my annual service at GTone, all good on drive home. Couple of days later, trying to start up for trip to Goodwood, flat battery. I charged the battery, no good, so jump started it from my trusty Ranger, but as soon as i removed the leads the car died. Alternator I guess coupled with poor battery (3 yr old Bosch S5). During service, I had a replacement used clock fitted and new alternator belt fitted. What do think? Is it the clock or belt? My thought are with the clock, would appreciate some help. Thanks, Steve

 

I've run my car with out the clock in place (I was checking for a different problem) so I don't see how the clock would stop it from running.

 

Could also be faulty door/hood/trunk/glovebox switches. On mine, also a '90 C2, I found that the glovebox light was always on. But like you said, the clock sounds suspect - one wonders if there is a short there.

 

Also had new bulb in the hood, but can't imagine that would do it. Have done searches on the subject, as you do, the clock is not a clock is it. I would refit the old clock, but I gave it to my 5 year old son for some electronic research. It's in quite a few pieces now!

 

The hood light is a very flaky design and well known for causing a current drain. Many of us have removed it because of that (I've disconnected the leads to it and taped them up). Having a bulb fitted and then the battery going flat within a few days is a pretty good indication that it is causing a big drain.

When you re-charged the battery did it crank but not start?

 

Charge up the battery and then test the running car . Does the voltage go up to a "charging" voltage when you have the motor running at a few thousand rpms ?

 

Boxey - there wasn't enough to turn the engine, enough to light internal lights but not the central locking. When turned key fully round all lights went out? I'll disconnect the hood light as suggested.
Indycam - either my charger or the battery is knackered, think I'll get the battery checked and replaced if necessary as its a fairly new Bosch S5.
I intend to get a soldering kit and have a go at the clock too. I thought the car dying when jump leads disconnected was an indicator of an alternator problem?
Thanks

 

What sort of battery charger do you have ?

Do you have a multimeter / dvm ?

 

Steve, it would definitely be worth getting a new battery since your existing one didn't appear to charge up, disconnect that light and start from there. It's well worth having a spare battery with these cars. I have two good ones and a mediocre one just in case!

If your existing battery won't store charge, the engine can die even if the alternator is running. BTW the alternator doesn't kick in until you rev the car past 3,000 for the first time. Well, that's what happens with many, including mine i.e. if I read the battery voltage with a meter just after starting the engine it reads just over 12V. Once I blip it to 3,000 the alternator kicks in and I get 13.4V (which is what you want to see with a healthy battery and alternator that's working).

 

If you have a multimeter / DVM , attach your car with jumper cables to your trusty Ranger .
Start up the porsche , when the porsche is running and the trusty Ranger is not ,
what voltage do you read at the porsche battery at idle and at 3000 rpms ?

The voltage regulator in the porsche should see a need to charge the porsche/trusty Ranger battery
and should put out a charging voltage .

 

Try cleaning your battery connections (i.e. make the battery posts and inner surface of the connectors nice n' shiny). Or a possible quick fix by twisting the connectors while they're still connected to the battery and relatively tight, a 1/4 to 1/2 turn CCW then 1/4 to 1/2 turn CW back ... repeat as required to ensure a good electrical connection. Tighten connectors to ensure a good mechanical connection.

 

Well, thanks for all your help. Today, I bought a new battery, disconnected the hood light and taped up terminals, cleaned up the battery terminals and fitted the battery. I found the the voltage across battery to be 12V and I got 13V with engine running after revving to 3000+.
Let's hope it was the new hood light that drained the battery and that the battery was past its best after a number of 'flats' and possible damage by over charging with my not so intelligent charger. I'll let you know what happens in the near future.
Thanks again.

 

Great news Steve. Fingers crossed for you that the hiccup is over.

 

Appears to be lite on charging

 

I read it to say 13 volts at idle rpm after a blip to higher rpms , but I might not be reading it right .