Thread: Stop Solenoid Problem...

your alternator control circuit is backfeeding the ignition relayb.

disconnect the alternator plug and try again.

if that fixes it probe the alternator control circuit for voltage with the engine running and the engine stopped with the ignition on and off in both instances

the ignition wire for the alternator should only have power on it while the ignition is on.

Thanks Dave.

The alt stopped supplying power when the ignition was off.. But while I was stuffing around the engine suddenly stopped - I had touched the stop relay.

Took the relay apart - it had worn contacts. Cleaned them up and now it is working. What timing to die! And i'm confused as to the behaviour of it.

Re the Alt feedback - does the battery light being illuminated confirm that the alt isn't generating power? Or is it possible for the feedback you described to occur while the light is on?

Maybe I had both problems?

Thanks again

the alternator backfeed issue is usually caused by an internal failure in the alternator. once the alternator excites the 12v ig wire gets power apllied from the alternator in stead of the ignition circuit, once it starts to do it it does it consistently. simply dropping the 4 pin plug off the back of the alternator cures it instantly.

the stop relay issue usually starts out as an intermittent fault and gets worse it also usually begins to cause problems on starting.

realistically there s 2 possible causes It was 50/50 and I guessed wrong.

if puling the alternator wire of the back of the alternator didnt work the stop relay and ignition relays were next.

I've had similar problems, one caused simply by corroded contacts on the relay due to it's position in the engine bay. Quick spray fixed that.

Thanks Dave for the info on alternator circuit. Put that in the book for future reference.

Pete

before you get into all that ^^^^^^^^

has the alt been upgraded??

its a common issue with 4bd1 after upgrading the alt.

turn the key off if the motor keeps running, then put your foot on the brakes. if it stops the alt is back feeding. ( or turn the lights on, just make an electrical load)

a diode is the solution. but i have never bothered.

Why bother stuffing around.
Both my Isuzus have a pull knob.
Keep it simple.

Originally Posted by 123rover50

Why bother stuffing around.
Both my Isuzus have a pull knob.
Keep it simple.

cause retrofitting that isnt legal.

Yeah the alt has been upgraded, but it worked fine for about 6 months before the above happened. Cleaning up the relay has worked and its been OK since - but if I have troubles again I'll definitely try the pedal/load trick.