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Hi all,

I have recently inherited an '89 Brumby with a few behaviours I would like to remedy. When the car is at idle revs, the dash lights dim, the blower fan slows down and the headlights dip noticeably. When the indicators are on the dash lights pulse with them. My interior light sometimes has a flickery quality to it.

It has been suggested to me that I may have a bad earth - somewhere. This problem disappears (lights go bright) as soon as I start driving or rev the engine. The dimming is directly related to the revolutions of the engine.

Thanks in advance to anybody who can assist me to track down the cause. Idle speed is good/correct and I don't want to increase it. I had thought that the alternator might need looking at, because this car has sat around for a while and was not regularly driven before that.

Might pay the get the alternator checked out. There should be a sender unit of some sort and the name escapes me now which charges the battery. I think it's a relay. Not real good on electrics though. Someone on this site will definately know the answer.

OK. You thought about the alternator. U done anything about that thought? If you don't have a multimeter you can get the cheapo one from Dick Smith, Jaycar, Super cheap? for about ten bucks. Measure volts of battery at engine off, engine starting and about 2000rpm. Between battery neg and pos.

Or the suggestion of a bad earth? Brumby has a piddly battery neg to body cable and a sort of decent one to the block from bat neg. Check that they are there, clean and tight

I had a car that did that, Cannot remember what I did to it, I think it was a bad connection or broken wire that has become thin that you couldnt see in naked eye.. I think it might be worthwhile checking the wiring connections & alternator tested so on...
Cheers
AP

Hi all,

Thanks for the responses so far. My car is in the shop today having some other work done on it so I will check things out when I can.

In case it is related, I should probably mention the other idle trouble I've been having. Sometimes the car vibrates a lot and jumps around at idle (very unstable), and I've had times when the revs will drop so low that the whole car shakes and warning lights come on the dash. In fact, before I got the carby fixed this would stall the car and the only way to get it to idle again would to be to drive 100m down the road.

I guess this is why we all love Subarus?

Maybe the idle is just too low to spin the alternator fast enough for it to keep the voltage up properly. If you can get it idling steady at about 800rpm or so (not sure whats standard for a Brumby) then it may solve the problem.

The low/unstable idle is an intermittent problem. I'd rather exhaust all other options electrically before increasing the normal idle speed. But thanks very much for your assistance.

the main earth strap to the chasis from the battery is probably loose or needs to be replaced or your alternator is on its last legs and will need refurbishing or replacing (or both)

it could even be the voltage regulator

as for the idle speed of a brumby it is between 750- 800 rpm

TOONGA

Gees, I hope you passed on the terrors of this beast to the guys working on it - just so they know and don't try to test drive it to get the lunches and find it konks out on them....

steptoe wrote:Gees, I hope you passed on the terrors of this beast to the guys working on it - just so they know and don't try to test drive it to get the lunches and find it konks out on them....

Hahah it's not that bad really. The car is wonderful to drive, absolutely beautiful.

Battery voltages check out - 12.5 before and after starting engine, rev engine slightly and let run for a while and it gets to 12.7. Unfortunately this was at 12am so I couldn't rev the engine much more, I'll do a proper check tomorrow.

I've started having my battery light come on after I start the car (until I give it a good rev) so it's really starting to look like I have an alternator that's about to conk out. It hasn't done the idle trouble to me for a while. I'm going to keep the multimeter on me (now that I've found it) and see if I can check the battery voltage next time I have the problem.

Recommend you take it to an Auto Sparky, they should be happy to test it and tell you what it needs for no charge.
12.7 is low, reckon your alt is expiring.
Daza.

yeah is that 12.7v whilst running? you should be getting around 14v at the battery whilst its running.

another vote for dicky alternator.

alex

The highest it ever gets is 13.8 if you sit on the accelerator for quite a while (without any accessories on). I took the car to the electrical guys today and while the alternator tested fine, they also think it's on the way out.

I also discovered today that the battery in it is from 2005 (still works fine though).

phantomD wrote:The highest it ever gets is 13.8 if you sit on the accelerator for quite a while (without any accessories on). I took the car to the electrical guys today and while the alternator tested fine, they also think it's on the way out.

I also discovered today that the battery in it is from 2005 (still works fine though).

The alternator should be producing 14v at just above idel if not at idle (it can do 13v or the like there). You should be able to pull the 14v with accessories on, lights etc. The battery could be part of the problem later on but it should still be charging 14v while the motor's running.

My fiance's VT had the factory battery for 8 years before it died.

Cheers

Bennie

regulator should be set for around 13.8v. undercharging usually is rectified by changing to new set of alternator brushes available from a autoelectrics supply mob prob for around $15 (holden ones were 7, magna ones were 12) just gottta solder them into brush holder. bearing are just as cheap too. this will fix 90% of altenaters

wrxer wrote:undercharging usually is rectified by changing to new set of alternator brushes

This is what I was informed.

EA alternators are _just_ adequate for the load on them (50A on EA81, 55A on EA82 from memory). I've had to roll-start my Brumby from sitting in wet weather with radio, headlights & wiper going (stopped the car for 10 minutes, battery was drained too far to turn over engine). A bolt-in replacement is the Nissan Maxima unit from the late 90s, 90A from the factory and you just need to file back the spacer so it lines up with the crank pulley.

Dean.

dfoyl wrote:replacement is the Nissan Maxima unit from the late 90s,.

Thanks for that - but I thought it was the late 80s/early 90s with the J30 Maxima?

I have installed the Maxima alternator (90A). Everything was great for a day (amazing improvement) but now I have worse trouble than before. Battery is not charging properly, power is very low and I'm starting to have trouble turning over the engine (won't start, very low voltage at battery). Again with the battery light coming on after starting the car until you give it a good few revs.

Surely the 90A Maxima alternator should be generating enough power at normal idle without having to put an oversized pulley on it? Can somebody confirm that the Maxima alternator should definitely be able to power everything at normal Brumby idle? That was surely the idea of upgrading it in the first place.

Seems I have replaced one dud alternator with another. I'm planning to put a new battery in as well but it really bugs me that everything was excellent straight after the install, then went downhill the day after.

what is the alternator charging at, you may find you have cooked your battery if it is over charging

Ive seen the buggers bubbling like they were boiling funny but really dangerous

TOONGA