voltage

[Javier]

I would get an AC voltage reading at the alternator post, an excessive AC voltage there would be a symptom of open diodes (too much ripple), thus having less than a full bridge 3 phases rectifier for the alternator output. This could cause low voltage output, as the tri-diode feeding the regulator is OK. (in this case, voltage at pin 12 of the diagnostic connector may be higher than the battery voltage itself).

Regarding the A/C fan, I understand that E32 have a two position blower switch, maximum and automatic (progressive). If so, no sword or resistor pack, but final stage module. Check F21, it may be the culprit, but there should be more than just blower problems (some indicating led's missing in the A/C control, for example).

Javier

[Whit]

Update: I think the low voltage is just a bad power or ground wire from alternator. Lots of resistance on the power wire coming from the alternator. The wire gets really hot, too. Will get a reading straight off of the alternator to see if it is better and replace wires and connectors and retest. Will let you know if we need to move on to alternator rebuilds, etc.
The A/C cabin fan is the other issue. There is a variable fan control (not simply 1,2,3,4) on the dash. It only works on the highest setting. How can I tell if I have a "sword?" I believe my car to be an '88 E32 750il manufactured 6/88. How about a blown fuse or sticky relay? It seems strange that the sword (if I have one) took a dump the minute they did this work. Does this car have a "final stage module" as mentioned above or a sword? How do I check? Shogun and I have similar Japanese versions. Shogun (or anyone that knows), which is it?

[Whit]

I would get an AC voltage reading at the alternator post, an excessive AC voltage there would be a symptom of open diodes (too much ripple), thus having less than a full bridge 3 phases rectifier for the alternator output. This could cause low voltage output, as the tri-diode feeding the regulator is OK. (in this case, voltage at pin 12 of the diagnostic connector may be higher than the battery voltage itself).

Regarding the A/C fan, I understand that E32 have a two position blower switch, maximum and automatic (progressive). If so, no sword or resistor pack, but final stage module. Check F21, it may be the culprit, but there should be more than just blower problems (some indicating led's missing in the A/C control, for example).

Javier

By the way, where do I find pin 12 and F21 if I want to check them?

[Javier]

the final stage, but checked 1994 wiring diagrams. Will check ASAP 1988 and comment, but per your description on the control (progressive setting plus a Max. click, it should be just the same as for 1994. The click is handled straight by a switch and a relay in the final stage, do not depend upon electronics. The progressive setting is electronic controlled via a power transistor in he final stage, and all the circuit is feed by F21 (in 1994). F21 is in the front power distribution box (engine compartment, were all the fuses, CCM and LKM lies).

Javier

Edit: For pin 12 on data link connector see this link. Think you do not need it any longer.

http://www.unofficialbmw.com/e36/ele...ce_lights.html

[Javier]

control is "The sword" not sure though if there are more than one type, as your control has nothing to do with 1, 2, 3, 4 stages. You can take a look at your car final satge and this links and confirm/repair. (check F21 fuse first).

http://www.bimmer.info/forum/showthr...55805#poststop

Javier

[Whit]

control is "The sword" not sure though if there are more than one type, as your control has nothing to do with 1, 2, 3, 4 stages. You can take a look at your car final satge and this links and confirm/repair. (check F21 fuse first).

http://www.bimmer.info/forum/showthr...55805#poststop

Javier

Thanks!

[Whit]

Geez. Still no joy on the low charge. New voltage reg, then new power and ground wires gave a LOWER voltage while running. Looks like the diode assembly is shot. Sending the alt to the repair shop for a rebuild. Will let you know. The mechanic is still checking out the A/C cabin fan (sword) to see if he has any luck resoldering the board on it. Sheesh.

[Whit]

Update: A/C cabin fan is now working! Sword needed only a resoldering of all components and works perfectly now. No new parts.
We will see if the repaired diodes fix the alternator issue and the low voltage. Update tomorrow.

[Karl]

Do an AC voltage check at the alternator terminal (ripple voltage), if it's greater than spec that will tell you if the diodes are going. Then do a DC voltage check to see what the actual output is at the alternator. Since you've already replaced the voltage regulator (on mine that includes new brushes), low output means it's time for rebuild or replacement.

If the checks at the alternator are OK, then you have a bad connection somewhere, and the way to find it is by checking voltage drop, component to component, in the circuit. The battery ground cable is one suspect, also ground resistance between the alternator case, brackets, and engine block. When you start digging for a voltage drop it's kind of a treasure hunt. Good luck.