How To: Diagnosing and bulletproofing your A/C

[gluaisrothaii]

New here...my DMC arrives in a few days

Does the stock AC clutch circuit incorporate a clamping diode to limit the voltage spike on disconnect?

Thanks,
Ken
VIN 46**

[Bitsyncmaster]

New here...my DMC arrives in a few days

Does the stock AC clutch circuit incorporate a clamping diode to limit the voltage spike on disconnect?

Thanks,
Ken
VIN 46**

No. Some cars that spike gets into the alternator circuit and you see the charge fail light flash. There are other electronics that can have problems. It all depends on how the harness is laid out and how good connections are.

[gluaisrothaii]

No. Some cars that spike gets into the alternator circuit and you see the charge fail light flash. There are other electronics that can have problems. It all depends on how the harness is laid out and how good connections are.

Thank you sir. I'll probably install one given the content on this thread. ACS has a handy one here for aircraft master & starter relays. Will be a good first mini project. There's a long list....

Best,
Ken

[Bitsyncmaster]

Thank you sir. I'll probably install one given the content on this thread. ACS has a handy one here for aircraft master & starter relays. Will be a good first mini project. There's a long list....

Best
Ken

That unit looks good. I used a zener but it really is a negative 200 volt spike at the clutch and I did not see any positive voltage ringing. So a diode will clamp that.

[ritztoys]

Dave, Can you share what you did with adding your zener diode and how connected. I've had a voltage spike in my electrical system that keeps 'frying' my clock (from yoda of Germany).

[Bitsyncmaster]

Dave, Can you share what you did with adding your zener diode and how connected. I've had a voltage spike in my electrical system that keeps 'frying' my clock (from yoda of Germany).

I did make a few kits but never put it on my web site.

[ritztoys]

Thank-you Dave......I'll be heading over to my electronics store and seek-out this diode, install soon to follow!

[ritztoys]

Dave.....I forgot to ask, does this kind of diode 'face' a certain direction or does it matter?

[Bitsyncmaster]

Dave.....I forgot to ask, does this kind of diode 'face' a certain direction or does it matter?

If you put it in backwards it will blow fuse #10 or the diode. The banded end goes to the clutch wire and other end to ground (compressor frame). If the diode has a pointed end that end is same as the banded end.

[ritztoys]

Thank-you Sir, I appreciate your reply (hadn't installed just yet)...