Just got my "new to me" 2003 MC-S up and running after several months of engine work. I sent the PS pump out for rebuild so it should be in good shape (then they announced the extended warranty! argh).

I have some software that lets me "actuate" the power steering pump from software and it will run - I can set it to 50%, 100%, etc. I can hear it running, and the steering wheel turns easily while I am actuating it.

But, I am not getting any power steering the usual way (can't hear the pump and it feels super stiff). I checked the 100amp fuse on the bottom of the engine compartment fuse block and it is fine. Took it out and metered it just to be sure.

I found one of the 5A fuses in the passenger compartment fuse block was blown. I did change that first. The other 5A fuse looks ok.

Is it possible the previous owner somehow had the PS turned off in software? What else could keep an otherwise working PS pump from running?

 

Look at the steering wheel shaft u-joint....if the pump is on...can cause issues..
They wear...and cause stiff steering...
For the pump to run...the alternator must be running...and outputting enough voltage...there is a sense wire....
Extended warrenty began in May 2013....so guess car has been down a bit. Good luck.

 

That helped. Voltage was a little low - it could still start and run, but it seems like it was low enough to lock out the PS pump.

 

Strange my power steering pump will run with the key in the second position

 

I've got a follow up question. I'm struggling to solve what is now a low voltage problem (that caused the PS to kick out). I replaced the battery as it was a little old and may have sat too long. Car runs and PS works with the new battery, but voltage is low when running. Makes me think alternator, but...

I removed the alternator this morning and found the terminals to be really corroded so cleaned that up and took it in to Advance Auto for testing. They were able to hook it to the test machine and it said it was fine. I cleaned all the ground leads and battery cable connectors (and that engine compartment terminal) before putting the alternator back.

Since then, I am still getting about 12.2 V at the battery terminals (same at the engine compartment terminal) with the engine off.

And I am getting about 11.8 V at the battery terminals with the engine running. (DMM readings)

1) First, I have a 0.4V difference between my digital multi-meter and what the scangauge is reporting. When the DMM says 12.2 V, scangauge says 11.8. when DMM says 11.8, scangauge says 11.4, etc. Does anyone know where the Mini gets the voltage signal from? Is it a standalone sensor? Where is it?

2) Anyone have experience with the parts-store alternator testers? Is that definitive? From the symptoms, I would say the alternator/regulator isn't working, but it supposedly tested OK.

Thanks again,

David

 

I'd say that alternator is dead you shoud be getting 14.7 volts at the battery.

 

Have you checked the grounds....
The one by the top engine mount is troublesome....if high resistance, it can cause issues.
Might be worth cleaning it up just to rule it out.

 

Thanks for the ideas.

I was hoping the dirty terminals on the alternator would be the silver bullet, and after seeing how bad it was, I did clean all the ground connections I could get to and the battery cables and the connection at the engine compartment jumping block.

I also confirmed low resistance readings using the DMM between the alternator case and the chassis ground after the alternator was re-installed (the meter was oscillating between 0.0 and 0.1 ohms - think that was pretty good :-) ).

BUT, all that didn't solve the problem.

 

Don't know much about the auto parts store testers but with engine running you should be in the high 13v - low 14v. What's the return policy on an alternator? Might be worth replacing..also did you check the ground wire zippy called out?

 

Ohm readings in the 0-0.1 range are not always very accurate on meters.
It would be better to check the voltage drop across the ground to alt.
That should be not very many mV with the car running.

 

Still stuck .. an update.

Got another Denso rebuilt alternator to try. Same results with the new one.

Checked voltage drops to confirm ohm readings. Voltage drops are very small (most close to zero, the largest I measured was 20 mV).

Thought the 3-pin connector going to the alternator looked sketchy so cut it out and fitted a new one - no change.

Removed and inspected every single fuse - didn't find any bad ones.

Does anyone have experience looking at the PWM signal that tells the alternator how much juice to produce? My Bentley manual has some cryptic instructions but it leaves a lot to the imagination...

I will probably try to trace the signal wires going from the alternator to the engine computer this weekend and look for shorts/open from that angle. I can't find anything wrong on the "power" side of things.

 

im having this problem now. im getting 10.8-11.5v at idle and when the a/c is on and i'm in traffic sometimes it goes at 8.8-9.4 that's the time my steering feels so heavy and sometimes the dsc and abs lights on.

thinking of having my alternator regulator changed

 

Check the grn/wht wire at the alt for 12 volts - supplied by fuse #39 in the footwell fuse box. The blk/yl wire should also have 12v from fuse #40 and that circuit goes through the alt warning lamp.

 

Thanks for all the suggestions and encouragement. Its been solved. PEBCAK as my IT friends would say.

I think I have the most immaculate and low-resistance ground connections of any mini that has lived. They were cleaned and recleaned and checked and rechecked, but were not the source of my problem...

When I was installing the engine, I managed to attach the B+ lead going to the rear to the correct post on the starter solenoid and the B+ cable heading to the alternator to the _other_ post of the solenoid (which is wrong, they go to the same terminal). Of course, this means the alternator was not in the charging circuit.... or at least was dumping current through the solenoid coil. I'm still surprised it started and run and didn't blow a fuse or throw a code, but it didn't.

 

you have a picture?

 

The right way to connect the battery cables at the starter first (image with green arrow), I found this image on the PelicanParts website (Thanks!) for DIY clutch replacement.


The wrong way next (which I have since corrected).

 

will look into that thanks