Any way to bypass voltage damper for testing purposes - 96 xj6 4.0 litre??

By voltage damper do you mean the voltage regulator or the noise suppressor as that dampens the reflective wave pattern after the rectifier converts the AC generator full wave pattern to a somewhat DC signal ? To test the noise suppressor put the meter on resistance and a good one will climb in value as the meter charges up the capacitor which is what it is . Short the terminals to discharge and watch it climb again .

The regulator bypass will allow to much excitation to the field windings which will burn up the generator wires . Otherwise you look for the B + post final output of around 13.5 to 14.5 volts .

https://www.ebay.com/itm/ALTERNATOR-...AAAOSwLVZVlHuJ

suppression module. trying to diagnose a alternator issue right now, and have been told to bypass it to properly check it. no way to eliminate the suppression module completely? we've put a phone call in to a tech support for assistance.

If you remove it you would get dirty DC power that would effect many things including radio as a classic example .

If you but a meter on the battery positive post and read 13.5 to 14.5 volts DC as you run the engine you have a good regulator ( although it can fail as it gets hotter in a drive ) . This 13.5 is above the battery voltage of 12.77 so the 1 volt or so charges the battery .

There are some items tapped into the voltage regulator car wiring before the actual alternator that can suck the signal down and kill the alternators output .

Any questions , just ask

We were told to bypass the suppression module to check the generator to rule out generator issue for the battery light or if there was an issue elsewhere in the system.

I would recommend keeping the suppression module intact and run the engine to see if you have the recommended 13.5 to 14.5 volts . You can remove the alternator and the auto parts store will spin it up on a machine for free as they want to sell you one if it's bad . Get the printout of the results

Do the capacitor test on the suppression module as there is a connector you can remove not far from the alternator terminal post . If The Cap is bad it will be obvious .

suppression modules don't fail very often .

On a practical side , before you remove the alternator . If you can run the car intact to the auto part store they can check the battery at the same time as it may not be excepting a charge . Today's batteries are junk so you can't go by their age , even new ones . As the battery gets below 11.5 volts the engine ECU will act up so have someone follow you with jumper cables to recharge if necessary .

Hi YEOMANSC,

Welcome to the Jaguar Forums! It's great to have you with us.

It might help us offer the most assistance if you could give us a little more background. Is the only issue the illuminated battery light on the instrument cluster, or is the car exhibiting symptoms of a failing battery or charging system issues?

In addition to the tests Lady P has outlined, you can also do some basic tests of the alternator, the diodes in the rectifier, and resistance and voltage drop in the battery power-alternator wiring. The document at this link explains the test procedures:

http://assets.fluke.com/appnotes/aut...e/beatbook.pdf


Cheers,

Don