Help!!....Too Many Warning Lights

[mbenzo]

Hey Crew, I need a suggestion. I own a '84 300 DT with right under 300K. I haven't driven it in about a week until this morning. The car runs normally, but I have too many warning lights on the dash that all come on when the car is started. The low fuel light is on (its full of diesel), the battery light is on(it cranked right up as normal) the red brake light is on (E- brake is not engaged), and a yellow light with a circle thing on it (not too sure what this is). I had a friend who works on cars take a look and he was unsure do to it being an 84 300.
Any ideas what would cause this electrical problem would be greatly appreciated.
Thanks!!!!

[pawoSD]

Just a guess but it might be a voltage regulator or alternator problem, the lights all stay on like that when the alternator or voltage regulator aren't working properly. It could be that the brushes on the voltage regulator in the alternator are worn just to the point of not making enough contact to provide sufficient power.....

[twr]

Originally Posted by pawoSD

Just a guess but it might be a voltage regulator or alternator problem, the lights all stay on like that when the alternator or voltage regulator aren't working properly. It could be that the brushes on the voltage regulator in the alternator are worn just to the point of not making enough contact to provide sufficient power.....

I had the same problem on the 82 300 SD and like pawoSD sez it was the alternator it was replaced and all lights went back to normal operation.

By the way, the "yellow light with a circle thing on it" is the brake pad wear indicator.

[ridinsmooth]

The same thing happened to me about the time my alternator siezed up. Had it replaced, has worked fine ever since.

[pawoSD]

You can even "simulate" the alternator failure, just stop the engine with the stop lever while its running normally then go look at the dash, radio/air system will still be on and all the lights on the dash come on.

I agree...your brushes are probably getting weak.
My eletrical system went nuts-o when the voltage started getting low.
Check into your alternator (do some searches or else you will end up at a parts store buying everything you may not end up needing that they tell you you need....)

[Jim H]

Originally Posted by mbenzo

...The car runs normally, but I have too many warning lights on the dash that all come on when the car is started. The low fuel light is on (its full of diesel), the battery light is on(it cranked right up as normal) the red brake light is on (E- brake is not engaged), and a yellow light with a circle thing on it (not too sure what this is).

When you turn the key to Postion II (run) these lights should come on. It is a 'self-test' to show you that lamps have not burned out.

Once the engine has started, they should all extinguish.

I'm probably re-stating the obvious, though...

Check your battery voltage before and after starting. It should be higher with the engine running. If not, there is a charging problem.

Best Regards,
Jim

[mbenzo]

Thanks For All The Great Info.

[vollpreuss]

I had a similar experience with my 85 300TD. After doing some research here I replaced the very worn voltage regulator. I happily reported 14.2 volts at the battery, lights functioning correctly, and thought the problem was solved. A day or two later I hit a bump - lights on. Another bump lights off and so on. At highway speed the lights would go off after 30 seconds of driving and stay off as long as the rpm remained at 2200 or above. The battery would eventually drain if I just drove around town. I was having some other work done to the car and asked my mechanic to look at it. Moral of the story: Check your wiring from the alternator to the battery as it could have a break in it.