Dash light emergency/hand brake

Post by **Caspar** » 23 Apr 2017, 05:35

Dear Forum,

my 1997 V70's e-brake dash light does not light up when I engage the brake. It does light up in ignition position I and II, so dash light itself seems to be ok. I did replace the switch in the console under the lever, no change.

I wouldn't care to much, but: Last year I forgot to release the brake and only realized this some time later, at 120 km/h on the highway. Since then, the wheels spin freely whatever you do to the lever (no surprise there I guess :/).

Before I even look at the brake (need it for inspection), I want this light to warn me next time.

Now sure where to look next. Any help is appreciated!

Best, Caspar

beigg · Post by **beigg** » 23 Apr 2017, 07:24

Unless you have that infamous cylinder condition, pos 1 should be accessory power, pos 2 should be accessory power + run.

Post by **cn90** » 23 Apr 2017, 08:21

The Parking Brake DIY is below:

viewtopic.php?f=1&t=54614

Post by **Caspar** » 23 Apr 2017, 11:21

beigg,

indeed, on position I only SRS light is on, on II all the other ones, including e brake. Once I start engine, ALL lights are off, even with e brake engaged.

So, the light itself is fine, and the new switch does not help. What else can go wrong?

Is there a dedicated fuse? Connection to the main controller?

Not sure where to look, the cable just disappears under the console.

Teddy1975 · Post by **Teddy1975** » 24 Apr 2017, 12:47

Caspar, test with a piece of wire connected to a good chassis ground and put the other end of that wire to the handbrake switch wire. If the light in the dash comes on when you start the engine with the wire connected, your new switch is either bad or the chassis connection to the switch is bad. Rinse the metal where the switch sits and try again. The switch itself may need a bit of wriggling as well to work.

If the light doesn't come on with the wire installed, it may be the wire that's broken or a connector that has come undone further under the console.

harojs · Post by **harojs** » 06 Sep 2017, 21:38

I have same problem.

HB dash light comes on during pre-start test, but not with HB

HB Switch itself checks good.

Still no joy in grounding the yellow HB light - dash bulb will not go on.

[Q] Anyone know where that yellow HB light wire goes to?

I can't find that circuit in the 1996 850 wiring diagram (Haynes -yeah I know ...)

-John

[email protected]

Post by **abscate** » 07 Sep 2017, 00:10

Aren't there two wires on the hand brake switch or am I confusing it with another car?

harojs · Post by **harojs** » 07 Sep 2017, 11:41

The '96 850 there is one yellow wire to the open/closed switch, which then uses just chassis ground.

I have manually touched yellow wire to good chassis ground while engine on - still no bulb light

I've got a hunch the yellow wire is going into the computer - but I can't find a good wiring diagram to chase the yellow wire

Guess I will chase manually ...