Brake warning light question (1 Viewer)

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Joined
Dec 16, 2010
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Location
Portland, ME
Since I got my '71 cruiser I've been slowly picking away at the electrical issues. This week it's the brake warning light. I believe it's wired correctly, although hard to tell because none of the wiring diagrams I have show the brake warning light, which is odd. :meh:
So with the parking brake on, and the key in the on position, the light comes on. If I start it up, the light goes out even though the parking brake is still on. Can someone tell me if this is how it's supposed to work? I realize that this light is also supposed to light if brake fluid is low. Thanks!
 
the light is supposed to be on with the parking brake engaged when the key is turned, regardless of whether the engine is running - it should go off when the parking brake is released

(unless fluid levels are low, then it would stay on)
 
(unless fluid levels are low, then it would stay on)

There are fj80 reservoirs that have fluid level sensors, but most of the fj40 masters have pressure switches. As I understand it, they would trigger the brake warning light when the brake lights are on but there is no or low pressure in one of the brake circuits. Right?
 
the light is supposed to be on with the parking brake engaged when the key is turned, regardless of whether the engine is running - it should go off when the parking brake is released

Crap. So any ideas as to why the light would go off when the engine starts?
 
Just for interest sake, my 1979 BJ40 has two brake lights:

Brake4.jpg

The left hand one comes on if the brake fluid in the reservoir is low. And it also comes on (as a "bulb check") whenever I turn my key into the start position (to crank the engine).

And the right-hand one is operated by the handbrake/eBrake to show whenever the handbrake is on.

And neither light can shine with my key "off".

:beer:
Brake4.jpg
 
diagram

Maybe this helps. The light on/off situation is also depending on the brake fluid level and/or the pressureswitch(es) on the bottom of the Master Cil.

brake light.JPG

Or this diagram (I have this version)

Image-01.jpg


Good luck. :wrench::beer:
brake light.JPG
Image-01.jpg
 
Maybe this helps. The light on/off situation is also depending on the brake fluid level and/or the pressureswitch(es) on the bottom of the Master Cil....

Those FSM pages are interesting Rudi.

Toyota wired up my low-vacuum switch to an audible alarm and not to any dash-lamp.

I have never come across a wiring diagram that covers my setup .. yet I know it is completely ex-factory (ie. unmolested).

:cheers:
 
Hi Tom,

I have in front of me: Land Cruiser (BJ40,43) 24V wiring diagram (Except USA & Canada) 5 pages wide and printed at Toyota 1974, including the buzzer for the low vacuum alarm.
If you are interrested I can send to you by PM.

Rudi
 
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mailbox full

Deleted. message was meant for somebody else.
Sorry.
 
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Thanks Coolerman! I suspect the ground at the master cylinder.

it is more likely the adjustment of the piston in the brake pedal switch, as Coolerman said
 
it is more likely the adjustment of the piston in the brake pedal switch, as Coolerman said

Well, my celebration was short lived. Now I can't get the red light to go on at all. So something else is up, but I'll try the brake pedal switch adjustment too. Thanks for the help!
 
yeah, that circuit is tricky

and the brake pedal switch is a bitch to get to
 
Just a suggestion but on my 76fj40 the brake and seat belt warning lights are side by side and if the wires were crossed the brake light would come on with key on and go right out when engine started. I am not sure if a 71 has a seatbelt warning light.
 
BJ40Green, what manual (Publisher and manual#) did you pull the diagrams from in post #9. That is the best drawing of that circuit I have seen. My OEM manual doesn't even show that circuit!
 
FSM

BJ40Green, what manual (Publisher and manual#) did you pull the diagrams from in post #9. That is the best drawing of that circuit I have seen. My OEM manual doesn't even show that circuit!

This comes from a Toyota FSM Publication No.98154 Third printing December 1976. It covers;
FJ40, BJ40 series
FJ43, BJ43 series
FJ45, HJ45 series
FJ55 series
It also has 6 fold out wiring diagrams. 4 of them are "Except USA & Canada" and the last 2 are "For USA & Canada"

I bought it from a guy in Holland (or Belgium) via "Marktplaats" which is similar to Ebay.
What else can I help you with?

Rudi
 

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