1996 960 Electrical Challenges

[Volvosaurus]

The latest:- The Youtube Bench-Testing video really is excellent. Thanks for sharing this.

However, I was unable to get a reading of 14-ish on the voltmeter (drop tester) when spinning the alternator. Both "old" and "new" did the same. I still can't work out what I was doing wrong - the only thing missing was a ohm meter. The voltmeter was across the test battery terminals, which were showing around 9v.

Gung-ho decision moment:- install the new alternator to the car and see if it gives 14-ish with the engine running. Such is the mechanic-friendliness of the 960's power train, it took around an hour to put everything back, PAS pump, radiator hose, leads, etc.

Et voila! Lights off at the dash, 14.5 at the car battery. Beer time.

I've probably been over-thinking the whole snag, but my lingering concern is that some rogue current comes in via the D+ and cooks this regulator.

The seat issue may just be coincidental, as Forrest has pointed out. Can anyone point me in the direction of a schematic wiring diagram? The passenger side seat is fine. Is there a relay that I could swap from left to right to test? I am aware that an accumulation of everything from sausage roll pastry to dead skin can stop switches in this area working. These switches are a touch intricate, so I am reluctant to take it apart. Testing at the connector with probe tips probably the place to start.

Thanks, all,. once again. Meanwhile, I have been replacing the rear axle sub-frame on a teenage Suzuki Swift, persuading rusted fasteners, repiping and fitting wheel cylinders, and at the point where this car was ready to be returned to a friend of ours, who needs it for commuting (and vital breadwinning), the alternator bearing decided to seize (the car had stood since early-January). The device was truly hemmed in, and I had to detach the timing side engine mount and lower the engine to release it. Playing with the Volvo was so much easier in access terms, and I bear the scars typically inflicted by working on a transverse-engine car. Meanwhile, customers needed my services, and the gloom and weariness related to a nasty virus painted everything grey, with a topping of "catastrophisation".

It's great character-building stuff, but at 63, I thought I might not need so much.

Eventually, however, we will drive things that are virtually disposable, so I suppose I ought to enjoy the spannering experience while I can.

Thanks, all.

[Volvosaurus]

Further developments.

Before shipping the old alternator back to the supplier, I asked a local long-established auto-electrical specialist to verify the output. They went beyond this, removed the regulator, tested the rotor, and found it was open-circuit. Good. So I haven't damaged the regulator.

It gets worse/better:- in refitting the centre console (removed when hunting potential loom damage, the heated seat light came back to life. Yippee! A broken core or gummed switch I can cope with. Not so some arcane heater element/thermostat issue.

On the test drive, the car played a teasing game with the brake system ("exclamation mark") warning light. It would come on on acceleration from a stop. A check revealed low fluid. I can handle that kind of issue, too. However, why it should suddenly come on after a month off the road, I really don't know. The pedal is firm.

The car was a "barn find" in 2014, bought "as seen" from a farmer for £250.00. I spent around £750.00 getting it roadworthy. Generally, apart from a clutch release bearing calamity, it has not needed much work, to the point that I don't know my way around it that well. Not bad for a car that will be 28 this year.

[Forrest]

At the risk of stating the obvious, if your brake fluid was full and then was on minimum you must have a leak somewhere. When did you last change anything on the brakes? I once got a very slight leak after changing one of the front callipers. It wasn’t leaving a pool of liquid, more a fine mist when in use.

If you’ve lost the contents of the reservoir while parked there’s probably a blown seal somewhere. Maybe in one of the callipers if the brakes otherwise feel normal. Otherwise the master cylinder.

[Volvosaurus]

Thanks for the warning. I don't cut corners on brakes, so I understand. There was the temptation to reuse wheel cylinders on the Suzuki which had slightly damaged threads.

Part of my test procedure after any work is a couple of emergency stops, following a check of the hardness of the pedal before departing.

The fluid was just on minimum. I did some cleaning and greasing of front calipers pre-MOT in October, and all was well

Once, I pushed back pistons to fit new pads, then forgot to check the pedal afterwards, and got a nasty surprise pulling up to the give way line at the end of our street (which emerges onto a busy A-road)...

I can't recall the last time I topped up the level. I suspect that this is simply a neglect of the level, plus some possible damp on the sensor contacts. I will keep an eye on it. Thanks for the wise advice.

[Volvosaurus]

Update, for the benefit of those who have kindly contributed knowledge.

The refurbisher bench-tested their alternator and declared "no fault found". However, they have paid for a replacement as a goodwill gesture.

Most strange, I can only suspect that the rotor windings have an intermittent fault. Cynically, I do think that they may be protecting their quality assurance stats by not declaring a fault.

The replacement is on the car, and so far, so good, although I need to do some work on the heated seat. The light is on, but no heat. I seem to recall a connector directly under the seat, fed by cables from a point close to the sill kick panels.

Meanwhile, the brake fluid level issue may have been accounted for by a stuck rear disc pad which went down to the metal. Other pads are only 25% worn. The calipers have lots of slack on their slider bolts, but need good lubrication to avoid uneven wear and an occasionally jammed (but undetected) pad.

Thanks again, folks.