jwbeck17

Has anyone else noticed any uneven brush wear on your KAE voltage regulators? I have two that seem to have heavy wear on the brush closest to the KAE, as it seems to have its edge worn off. Hard to explain, but I took pics.

The commutator band is worn unevenly to match. Earl and I suspect that the KAE brushes don't align perfectly to commutator grooves, and so voltage issues can occur.

Anyone else seen this?

In the meantime, Earl is getting the commutator bands smoothed out to see if that helps.

jwbeck17

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ROG100

This is one of those applications were we have little if any choice.
KAE, Bosch and Porsche (probably Bosch) are the only suppliers.
KAE is readily available and we sell for $13.50.
Bosch is currently not available at all the main wholesalers. When and if it is again price is circa $95.
Purchasing via Porsche is $245. I can supply an alternator cheaper.

Hope you and Earl find a solution.

jwbeck17

Thanks, Roger. Earl and I are figuring out if we level out the commutator, will the voltage regulator work correctly. When I put the new one in, there was no bevel in the brush, yet the voltage fluctuations still occurred.

Hopefully this works! If not, we'll probably be contacting you about a new alternator.

Alan

Fluctuations due to poor commutator connections would be very rapid at normal engine speeds too rapid for you to be able to distinguish them from just a voltage offset to the set-point (so usually just an apparently low output voltage). In fact the output would likely be very spikey - and you may hear this noise over a radio (esp AM).

If you have slowly changing fluctuations that are visible in headlights or audible in fan speed etc - it wasn't due to this.

Alan

Arnoud

Hi Jason,

During my end of March + early April MM + Silicon OPG & TB + WP main jobs plus numerous other WYAIT jobs, I had a look at my alternator and cleaned it and the regulator - which was possibly still the original one.
I did not replace it then, as all was working fine and both brushes still were/are of decent size (and additionally I had totally forgotten about it upfront, so I did not had a new replacement on hand either).

Perhaps the following pictures are of some use to you.

ammonman

There is another alternative for voltage regulators for the Bosch alternators. This guy sells both adjustable and fixed voltage regulators to the Volvo crowd. His units fit basically any Bosch alternator with 28mm slip rings and an external fan. I've been running his 14.5VDC fixed regulator for about a year now and it works perfectly. Voltage is very stable under load.

Mike

ROG100

Hi Mike,
So non adjustable fixed 14.5 regulator $24? Plug and play?
Thanks for the link.
Roger

GlenL

Hella, too. $19 for an S4 version.

ammonman

You got it Roger. Completely PnP. I haven't pulled it to look at brush wear or anything else for that matter. It's working just fine so I'm leaving it alone

Mike

jwbeck17

Great find. Once we get the slip rings smoothed, I may want to check one of these out.

ROG100

Mike - what made you choose 14.5v instead of 14.0v - is 14.5 a little too high for the battery.
Do you know if they are temperature compensated?
Roger

Alan

I would say 14.5v is too high for the battery. All regulators are temperature compensated (to some degree - that varies).

A higher voltage is NOT better - far from it. If too high it can boil the battery acid on a long trip - especially in hot climates.

Also a higher voltage set point is counter productive - you will run into the alternator power limitations sooner with a higher voltage, causing voltage droop sooner than if you set the regulator lower.

I think what most people want is a sufficient and more consistent voltage - not a high voltage (at least thats what you SHOULD want). A 5% voltage increase will cause an ~5% current increase and therefore an ~10% power increase. Given the alternator has a fixed max power envelope - using more power for the same accessories is a bad idea. For incandescent bulbs you will dramatically shorten their lives with increased supply voltage.

The remote adjustable volvo (Bosch) regulators are a good way to get less aggressive temperature compensation.

Alan

jwbeck17

I ordered the internal adjustable version and will see how that pans out.

dr bob

FWIW, on a Ford Explorer I owned for a long time (250k+) the factory charging voltage was 15. I'd been building an early Explorer owners' forum, and had back-door support from some Ford tech guys, so I asked about what appeared to be a higher-than-normal charging voltage. They came back with an explanation that considered the normal use patter for the cars, one that includes lots of idling at the drive-thru, short trips to the market, picking up kids at school. Or slogging through snow or other not-highway-driving situations. They wanted to restore the starting drawdown as quickly as possible, and make sure that the battery was always in good enough state of charge that it could suffer those long-idling periods and still keep the AC and the fuel pump working. The vehickle came with a group 65 battery, a pretty good-sized battery, so it wouldn't draw down the voltage too low.

If I was sure the electronics (LH and EZK particularly) could stand 15 Volts, I'd be sorely tempted to run the charging circuits at that level. As it is, with the 14V Bosch regulator in my refreshed alternator, the temp compensation draws charging voltage down to low 13's on 85º ambient days, even before engine and charging heat loads are added. I'm almost ready to try the internal 14.5V fixed regulator to see if that helps enough, and then the external option mounted in the front left wheelhouse area under the headlight if the internal one derates too much with temp on the alternator.