Help Electrical Issue 300TE 89 Age old problem

[rcs hawaii]

Hi,

My 1989 300TE is acting up again. Tonight the car ran fine. I finally got the A/C going again and the dealer was nice enought to reset the radio no charge.

Then tonight while idleing at a friends house the car had issues. The a/c was runnng the entire time. The after driving away the ABS light came on, SRS light came on, wipers got slow and the a/c kept kicking down on its own. Did think much until after I went to the mall and came out to find that the car wouldn't start. I then went to the local auto parts store to get a portable jumper, which start the car right away. Then the car acted a bit strangely again. same issues.

I believe that it is the voltage regulator. I came home in the rain and hooked up a meter to the battery and found that with the a/c running and the car on I was only at 11.08 volts. I then went to the trusted 1987 300E parked next to my 300TE and popped the hood and the battery was at 12.57 volts. Had the wife turn the 300E over and the reading was the correct 13.85 or so.

Do you think I'm correct and its the voltage regulator??

Can I change the voltage reugulator while the altenator is still in the car????

thanks for all your time.

1989 300TE
1987 300E

[cheeryvampire]

As I mentioned in your other post, you can replace the VRM without removing the whole alternator.

All the symptoms you mentioned are very common to the alternator failing.

My suggestion to you is that you do not purchase a new voltage regulator module (VRM) until you have removed the old one or verified that the alternator is indeed still good. Mostly because you usually cannot return electrical components.

After you remove the VRM, take a look at the brushes. They are two spring loaded things that stick out. If they measure at around a 1/4" or 5mm then the unit is probably still ok. You will know the alternator will most likely be the problem.

For others that read this post... Whenever the first two lights to activate are ABS and SRS, this most commonly indicates a failing alternator or VRM.

-CV

[Six_wheeler]

Thank you Sir for pointing that out! I no longer shudder at the thought of the day the ABS light comes on! [:)]

Shady