Ccrocrover

New Member
I recently treated my truck, 96 Defender 90, to a chassis swap. A few things were disturbed and needed fixing and at the moment I am working on the brake warning light in the dash. I think it should come on during starting then extinguish. The bulb is fine, the reservoir switch is fine, if I short the connector the bulb lights.
So my question is what creates the check circuit on switch on? Older circuit diagrams in my Haynes manual (up to 94MY) show a relay but I can't locate it.

I guess this is an MOT fail?

Thanks
 
Doubles as handbrake light, I dont think it should come on during starting unless fluid is low or handbrake is on
 
The one on my 1990 truck has not worked for years, done the same tests as you Cc. I recall it came on when ignition switched on and went out when engine started. Passed a good number of MOT's
 
Pretty sure mine does not light up with ign on, no handbrake switch on the 200 models.
 
Defender1996-275 - Copy.png
should only come on when brake fluid low ,the hand brake should be a different switch ,not sure if the level switch is part of reservoir cap if so remove cap and this should put lamp on
 
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Unless you've got ABS (unlikely on a 1996 model) there's only two things likely to be able to make the brake warning light come on. One is a switch on the base of the handbrake lever so that the light comes on when the handbrake is on. The other is a switch in the brake fluid cap to indicate that the fluid is low. In most cases there's a cylinder on the underside of the cap - let the fluid drain out and the light should come on (if the ignition is on).
 
Light on mine works if I power it direct and the switch will work if connected out of the vehicle but nothing when fitted. I guess a wiring problem but can not be bothered to go further. Just looking at the reservoir in the old way works for me.
 
The warning light works fine if I have low fluid, it's just the bulb check on dashboard warning lights that doesn't happen. I'll ask the MOT garage if this is a problem.
 
The vehicle handbook says there should be a warning light check on ignition. Owned the truck from new, 26 years, fairly certain it worked in the past but starting to doubt myself! So the question remains - how does it switch the light on for the bulb check?
 
Mine's a TD5 so a bit later than yours, but it's a non-ABS model so shares part numbers with yours as far as the master cylinder and reservoir and handbrake switch are concerned. There's no 'system check' flash of the dashboard warning light when you switch the ignition on. Nobody at the MOT garage has ever said anything about it. Looking at the wiring, there's nothing in the loom or the dash panel that would do this. You'd only get this if there was an ABS control unit which controls the light as well as the ABS valve block.
 
The one on my 1990 truck has not worked for years, done the same tests as you Cc. I recall it came on when ignition switched on and went out when engine started. Passed a good number of MOT's
Mine's a TD5 so a bit later than yours, but it's a non-ABS model so shares part numbers with yours as far as the master cylinder and reservoir and handbrake switch are concerned. There's no 'system check' flash of the dashboard warning light when you switch the ignition on. Nobody at the MOT garage has ever said anything about it. Looking at the wiring, there's nothing in the loom or the dash panel that would do this. You'd only get this if there was an ABS control unit which controls the light as well as the ABS valve block.
Thanks for your thoughts, I couldn't see anything that would do it but worth asking in case I missed something obvious! Cheers
 
My TD5 does a brake panel light check, I have just tried it with the hand brake off and turning ignition on the light comes on for a couple of seconds the goes off, with hand brake on it stays on until brake lever released. A different vehicle I know but it may work the same way.
 
My TD5 does a brake panel light check, I have just tried it with the hand brake off and turning ignition on the light comes on for a couple of seconds the goes off, with hand brake on it stays on until brake lever released. A different vehicle I know but it may work the same way.
Thanks Scooby. Things moved on a bit by the time your MY 90 came out. I ran a 2003 110XS for a while and the ECU is a bit more advanced than my 300tdi.
 

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