I have a 1994 gs300, no accidents. I have replaced my alternator 4 times now, in the past two years! When I depress the break pedal the idiot light for my lights comes on! ALL my lights work!`now this is a new since the most recent replacement, when I hit the breaks my lights dim for a second then come back up even if I hold the pedal down. if I have all assesorys on and do the same the car nearly dies. on this last alternator rather than get a replacement I had this one fixed, the voltage regulator went bad. What would cause this?

 

It might b the battery die'n! Just somethin 2 check!

 

battery is new, replaced this week and had the old one checked. it was or is good and now sits on the shelf.

 

with the key in the accessory position engine off I get a reading of 11.3v on a freshly charged battery. with engine on and no extras turned on I get 13.4v if I turn on the head lights 14.2v and stays between 14.2v and 14.5v if I turn on every thing. When i hit the breaks with engine off it drops to 10.8v, engine on with no accessories it drops to 12.2v then jumps up to 14.5v.

 

do you have trac control?

if so when you depress the brake pedal the motor that supplys boost pressure may be drawing too much current (siezed pump etc), dragging everything down.

those pumps need fresh brake fluid (change out every 2-4 years) otherwise things corrode. not sure if there is a service interval for that since my manuals are all in Japanese.

 

yes I have trac control,

do you know how I could check if this is the problem?

 

does the Aristo brake booster fit? I have a front clip on hand I could swap them. (doing the swap in spring)

 

What I do for current drain or voltage issues is a to pull fuses or relays to at least isolate the problem load. you could also get the codes pulled too - as this will be stored on malfunction indication.

From the wiring diagram and it's from US 1995 I think...

Fuse "ABS#2" 40A powers the trac motor and ABS motor
Fuse "ABS" 60A powers the trac actuator.

Pulling these fuses will likely disable both ABS and trac so not sure if that will tell you anything definite.

It looks like your car will still have a conventional vacuum brake booster, and TRAC and ABS pumps. I don't know the car that well, just got an Aristo which does not have a vacuum brake booster.

 

suggestions on pulling these fuses? there deep cant get a hold of it! I pulled the relay for it and other than loss of abs/trac every thing seems ok no big power drain! is it safe to drive with this deactivated,

 

there is a little plastic fuse puller should be in the lid of the box. also instructions on how to use in the owner's manual.

driving w/o Trac is no big deal. w/o ABS - it used to be optional on a lot of cars. good season specific tires (<3..4 years old) do more for safety than both those things IMO.


at least on my '93 JDM..
twin turbo Aristo can't drive without the pump though as it is used for brake boosting - that is why the brake warning light comes on when there is a problem with the pump.