Notices
964 Forum 1989-1994
Sponsored by:
Sponsored by:

Engine Lid Light & Front Lid Light

Old 12-16-2011, 05:55 PM
  #1  
r15suk
Instructor
Thread Starter
 
r15suk's Avatar
 
Join Date: Jul 2011
Location: Reading, UK
Posts: 233
Likes: 0
Received 0 Likes on 0 Posts
Default Engine Lid Light & Front Lid Light

Can anyone help please?

When the engine lid is opened, the light does not come on, but if I open one of the doors it does. Also when I open the front boot the interior lights come on (but the front boot light doesn't).

My guess is that there is an earth fault with the engine lid light and the circuit is being made when I open the door. For the front i'm guessing the +ve supply to the light is the problem or the bulb has gone as the circuit is being made to bring on the interior lights. Am I on the right lines?

Also can anyone explain how the system is supposed to work regarding what lights come on when what is opened?

I have searched the forum, but can't seem to get the right answer. If it is there, please bear with me, it's my first technical question here

Cheers
Simon
Old 12-16-2011, 06:39 PM
  #2  
Makmov
Drifting
 
Makmov's Avatar
 
Join Date: Aug 2010
Posts: 2,274
Likes: 0
Received 2 Likes on 2 Posts
Default

When you open the door the interior lights should come on and go off either when you start the car or by timer.

If you turn off the car then open the door the interior light should come on and go off by timer after the door is closed.

When you open the frunk (front trunk) the frunk light should go on and the interior lights should come on, and go off when you close the frunk.

The engine lid is independant on should work with the opening or closing of the lid only. AFAIK at least that is the way it works on my 91.

Perhaps a short or malfuctioning door switch may be your problem.

I also found a short in one of my interior lights that I fixed by cleaning the contacts in the switch part of the light and now seems to be working proper.

Also when the boots for the door switch get old they get hard and wont allow the switch to opperate normally.

Could also happen to the boots on either one of the lids.

Sounds like you are kind of on the right track, and I would say the frunk is working correctly and maybe just has a bulb out.

The engine lid is perhaps grounding on the body somewhere causing the interior lights to come on.
Old 12-17-2011, 08:47 AM
  #3  
Harry Apps
Pro
 
Harry Apps's Avatar
 
Join Date: Sep 2004
Location: Norfolk, UK
Posts: 594
Received 20 Likes on 19 Posts
Lightbulb

Originally Posted by r15suk
Can anyone help please?

When the engine lid is opened, the light does not come on, but if I open one of the doors it does. Also when I open the front boot the interior lights come on (but the front boot light doesn't).

My guess is that there is an earth fault with the engine lid light and the circuit is being made when I open the door. For the front i'm guessing the +ve supply to the light is the problem or the bulb has gone as the circuit is being made to bring on the interior lights. Am I on the right lines?

Also can anyone explain how the system is supposed to work regarding what lights come on when what is opened?

I have searched the forum, but can't seem to get the right answer. If it is there, please bear with me, it's my first technical question here

Cheers
Simon
There is a common power supply to both sets of lights but the bonnet/engine lights should work independently and not rely on the door pillar switches. Suggest you remove both lights and check using separate earth leads. It's also not uncommon for the engine light to operate (lid closed) when the bonnet is open (ie 2 lights for the price of one!). These lights are often listed as a cause for flat batteries and I recommend that you consider replacing the bulbs with the LED type for less current drain.
Old 12-17-2011, 09:23 AM
  #4  
altarchsa
Three Wheelin'
 
altarchsa's Avatar
 
Join Date: Jul 2007
Location: Helotes, TX
Posts: 1,307
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Makmov
When you open the door the interior lights should come on and go off either when you start the car or by timer.

If you turn off the car then open the door the interior light should come on and go off by timer after the door is closed.

When you open the frunk (front trunk) the frunk light should go on and the interior lights should come on, and go off when you close the frunk.

The engine lid is independant on should work with the opening or closing of the lid only. AFAIK at least that is the way it works on my 91.

...................
That's not the way my '89 works. It is much simpler and more mechanical:

Open / close doors, or rock the interior light fixtures = cab lights on / of.

Open / close lids = respective compartment lights on / off, although there is a common problem getting boot light to go off by means of the contact switch.

Maybe the more contemporary timer operation was an option or an improvement with later models?
Old 12-17-2011, 10:01 AM
  #5  
DWS964
Rennlist Member
 
DWS964's Avatar
 
Join Date: Apr 2006
Location: Indianapolis, IN
Posts: 1,227
Received 26 Likes on 12 Posts
Default

The frunk light switch is tied into the alarm system also (at least on my 92). To test: pop the frunk but don't release the safety catch. Lock the doors, and the alarm is activated (LED's on door blink). Open the frunk, and the light should come on (and interior lights) and the alarm should come on. Loudly.
I think I read this test sequence in Adrian's book?
Perhaps the engine lid light/switch is tied into the alarm system also?

These cars and their intricacies continue to amaze me.
Old 12-17-2011, 10:16 AM
  #6  
Smokey7766
Racer
 
Smokey7766's Avatar
 
Join Date: Mar 2011
Location: Michigan
Posts: 380
Likes: 0
Received 2 Likes on 1 Post
Default

ok...perhaps very strange but mine is different also....the engine lid light (gone and no light on my RSA lid/spoiler) only worked when the frunk was open.... both lights worked by the front switch located near the hinge on the passengers side frunk lid...interior lights were not tied into either lid light at all.
Old 12-17-2011, 10:29 AM
  #7  
FeralComprehension
Rennlist Member
 
FeralComprehension's Avatar
 
Join Date: Jun 2010
Location: Detroit (Rock City); 1990 C4
Posts: 1,710
Likes: 0
Received 4 Likes on 4 Posts
Default

I think the timer/delay feature was added later; nothing of the kind on my '90 so far as I can tell, but the alarm is inop...
Old 12-18-2011, 02:05 PM
  #8  
r15suk
Instructor
Thread Starter
 
r15suk's Avatar
 
Join Date: Jul 2011
Location: Reading, UK
Posts: 233
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for all you responses, now i have something to work on.

Most important though is that I now know what to call the front boot/bonnet - a frunk!
Old 12-19-2011, 12:17 PM
  #9  
Makmov
Drifting
 
Makmov's Avatar
 
Join Date: Aug 2010
Posts: 2,274
Likes: 0
Received 2 Likes on 2 Posts
Default

Maybe it is tied into the alarm. My car has the factory Porsche alarm.


Thread Tools
Search this Thread
Quick Reply: Engine Lid Light & Front Lid Light



All times are GMT -3. The time now is 09:10 PM.