Handbrake and Battery Light Stays On

[Old.Tony]

Interesting issue with my car yesterday, and discovered a new possibility for this light combination.

Scenario: had to use the horn. Shortly afterwards, the battery warning light and the handbrake light came on. Shutting the car down and restarting it didn't fix it. Alternator started producing 15.2V to 15.3V. Putting the headlights on lowered that to 15.0V. External voltmeter confirmed the slightly higher than standard charging.

Checked over the car, belts ok, alternator pulley ok, plugs and connectors on alternator ok, battery terminals clean, fusible link ok, no obvious sign of rats eating the cabling.

So I've checked the horn fuse (the black fuse/relay box near the brake booster) and the 15A fuse was blown. Replace this and everything is back to normal

It's not always the alternator. We've several threads on this forum (like this one and this one) that have this warning light combination - but here's yet another possibility!

So if you ever see those lights appear and see that sort of voltage, try the horn. At worst you'll annoy the car in front of you, but at least that won't be a Hilux, right?

 

[Phunk]

Interesting issue with my car yesterday, and discovered a new possibility for this light combination.

Scenario: had to use the horn. Shortly afterwards, the battery warning light and the handbrake light came on. Shutting the car down and restarting it didn't fix it. Alternator started producing 15.2V to 15.3V. Putting the headlights on lowered that to 15.0V. External voltmeter confirmed the slightly higher than standard charging.

Checked over the car, belts ok, alternator pulley ok, plugs and connectors on alternator ok, battery terminals clean, fusible link ok, no obvious sign of rats eating the cabling.

So I've checked the horn fuse (the black fuse/relay box near the brake booster) and the 15A fuse was blown. Replace this and everything is back to normal

It's not always the alternator. We've several threads on this forum (like this one and this one) that have this warning light combination - but here's yet another possibility!

So if you ever see those lights appear and see that sort of voltage, try the horn. At worst you'll annoy the car in front of you, but at least that won't be a Hilux, right?

Hang on.. a blown Horn Fuse on it's own circuit and not magically routing through the BCM or anything silly like that, caused those issues??

a HORN FUSE???

I've secretly been falling for the GWM Cannon as the possible next ride (value for money). I'd hate to see what happens when the Horn Fuse blows on that thing..

 

[Old.Tony]

Hang on.. a blown Horn Fuse on it's own circuit and not magically routing through the BCM or anything silly like that, caused those issues??

a HORN FUSE???

I've secretly been falling for the GWM Cannon as the possible next ride (value for money). I'd hate to see what happens when the Horn Fuse blows on that thing..

Yep, seems odd. Look, it's possible that my car has developed another issue that, with the horn fuse missing, translates into more problems (like the alternator voltage rising). I will be doing the electrical connection cleaning task soon, and I'll pull the horn fuse just to see if the problem's gone away. Everything is working as expected, I recently replaced the windscreen washer pump as well, so the whole car is behaving nicely.

 

[Phunk]

Can I confirm with your D40, that the 12V socket on the bottom of the AC / Stereo Panel is permanently powered?

Mine is always live which is a blessing and a curse.

 

[Old.Tony]

Can I confirm with your D40, that the 12V socket on the bottom of the AC / Stereo Panel is permanently powered?

Mine is always live which is a blessing and a curse.

Yes it is. It's the one I use for my CB radio. The one inside the centre console beneath my elbow is only on when accessories are on.