Skip navigation

Power hood & hand break/interior lights?

Post

Back to the top
2 separate issues.

1)
My hood works with the engine running. I know it shouldn't, but I curious as to how it should be wired.

There is the main power with the thermal fuse, then there is another red, and a black. The black doesn't seem to do anything.

2)
I've done that's stoped the hand brake light and interior light from working. Are they both negative switched? Any ideas, what would kill both.

Whip
/wip/
Noun - Car

When the steering wheel was first put into use in automobiles, it was called the whip. The term has now been generalised to classify any automobile.

Post

Back to the top
2. On the interior light you have a switch, it has 3 positions on/off/0n with doors open.


So if the light works in doors closed then you have a ground issue with the door switches.  On the lamp there is a Red wire (power), a Brown wire on by switch, and the brown/whites that come from the door switches.  Verify that 1. Your bulb is good, and 2 that you have 12V to the bulb on the red wire to ground.  If they are good, the continuity test to from the Brown wires to the frame.
(you will have to open and close the doors to check the brown/white. If you have 12V and the Ground at the Brown wire, and your bulb is good, then you probably have a wonky switch or bad lamp holder.

There is a button switch on each door "A" Pillar that is held in by a single screw, they get tarnished and don't make good connections, be warned that the itty-bitty wires are short and will become disconnected and fall back into the "a"" pillar so be careful.

Same for the E-brake light, the switches can get knocked out of position and either come on all the time or not at all if the wire is off, it grounds the lamp when the e-brake is up turning the lamp on, so I suspect that the wire is broken or off the switch or that the switch is bad.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

Post

Back to the top
1, on the hood working with the engine working, It depends, if you are in Neutral engine running and the parking brake fully engaged, then it should go up or down.

On autos you have to be in Park, with the E-brake up.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

Post

Back to the top

Briano1234 said

1, on the hood working with the engine working, It depends, if you are in Neutral engine running and the parking brake fully engaged, then it should go up or down.

On autos you have to be in Park, with the E-brake up.

Hi Briano1234, all mine only work with the key in the ignition unturned,  and manual drive cars.  i'm 99% this is correct, briefly i did run a live directly to the hood to make work, until i had some other issues looked at by richard at crazyquiffs.
Carl chortle may have wiring diagram.  

Lights and switches just change as and when you think switches are rotting away.  clean all connections to body work. And follow briano1234 advice


On the drive
T25 Diesel…sameoldblueshi£ (currently under resto)
Rocco gt2….1990 secret 2…(currently under resto)
Mk4 99 1.8t indigo blue Gti with 43k miles
Caster 93 clipper JH Green cabby
Snowy 91 GTi White cabby( sat waiting for inspiration)
Myvalver 89 GTi Grey mk2 16v
Yuppy Flu 91 GTi Flash Red Sportline


 Golf mk1 owner's club on Spotify

Mk1 golf owners club playlist: Golf mk1 owner's club playlist - YouTube

Post

Back to the top
Thanks for the help so far, guys.

I'm pretty sure sure it's not the door switches. They worked fine before I slid the fusebox back in.

Do we know if the interior light is switched by the negative or positive? Mine is slightly odd in that it stays on for a few seconds after the door is closed. Interestingly, in the "always on" position it works. It's only in the "door switched" position that it doesn't.

My understanding of the hood is that it is powered on by the SU circuit (key in ignition but not turned), but doesn't work when the engine is running.

There are a few circuits I don't quite understand…
The handbrake light is negative switched, right?
The battery light on the instrument cluster goes out when the engine is running so there must be a way it knows. Power from the alternator perhaps.

The black wire from the hood comes with a splitter suggesting it goes to where something else is already connected. It's not needed to power the hood, so perhaps it disables the hood when triggered?

Whip
/wip/
Noun - Car

When the steering wheel was first put into use in automobiles, it was called the whip. The term has now been generalised to classify any automobile.

Post

Back to the top

On the drive
T25 Diesel…sameoldblueshi£ (currently under resto)
Rocco gt2….1990 secret 2…(currently under resto)
Mk4 99 1.8t indigo blue Gti with 43k miles
Caster 93 clipper JH Green cabby
Snowy 91 GTi White cabby( sat waiting for inspiration)
Myvalver 89 GTi Grey mk2 16v
Yuppy Flu 91 GTi Flash Red Sportline


 Golf mk1 owner's club on Spotify

Mk1 golf owners club playlist: Golf mk1 owner's club playlist - YouTube

Post

Back to the top
The battery light on the cluster is a 2-fold device.

The Blue wire off the alternator is used as an exciter circuit to start the field to allow charging circuits of the alternator to start producing power (very generic description).  Once the alternator is producing power (current) the voltage goes above the battery input to the battery light and the light turns off via a reverse biasing on the diode that turns the battery light off.  (some times you have to burb or blip the throttle above 1000 rpm briefly to get it to turn off) This is because of bad contacts on the voltage regulator to the alternator that need to be cleaned, and or the pulley that drives the alternator isn't sufficiently or effectively aligned or tight to the belt.  Once you get the under speed or under voltage to rise it turns off and the alternator starts to charge as well as turns the battery light off.  

Conversely the Instrument Battery light at starts feeds 12V via the blue exciter light from the battery through the cluster battery light to the alternator to start the alternator to produce voltage and current by building the
field on the coils.

When the output of the alternator drops below 12V the alternator shuts off and the car is suing the battery to power everything and the battery light starts to flicker dimly then glows brightly and if you are running at night with your headlamps on, and the radio blaring you can run till the battery is sufficiently discharged to stop your fuel pumps.


What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

Post

Back to the top
Great description, thanks.

Looking at the wiring diagram for the hood, One wire is from SU, and the other from switched power(P). My guess is that SU powers on the hood and switched power disables it. I'll have to test this.

I generally only open it with the engine running as it draws a fair amount of power. The handbrake switching would have been nice.

Whip
/wip/
Noun - Car

When the steering wheel was first put into use in automobiles, it was called the whip. The term has now been generalised to classify any automobile.

Post

Back to the top
Your handbrake light and roof issue is probably  connected (literally). Handbrake light has a black wire running to it .This is usually connected to G2. The roof loom also has a black that connects to G2. This wire stops you using the roof with ignition turned on. Because these these two wires need to be connected to G2, the black on the roof loom has a piggyback wire that allows both wires to be connected to G2.

Post

Back to the top
Well I opened the door to take a look, and the light came on.

¯\_(ツ)_/¯

Whip
/wip/
Noun - Car

When the steering wheel was first put into use in automobiles, it was called the whip. The term has now been generalised to classify any automobile.
0 guests and 0 members have just viewed this: None.