Power fluctuations on `83 240DL

[rektide]

Hello all,

I'm on the road and my 240DL has started giving me serious power
problems. Turning on anything electronic reduces power from the rest
of the system; the car just stopped being able to keep up with the
power demands. For example, hitting the brakes causes the lights to
dim. Turning the climate control fan on dims the lights- every step up
brings quite a noticable drop in brightness. Also, high beams get
stuck on, I have to turn the lights off, flash my high beams, and then
turn my lights back on to disenguage high beams.

I've been running a 300 watt 120v inverter and a decent sized stereo
for two weeks now off the system. They tap onto the positive terminal
of the battery, and are grounded onto the chassis; I've disconnected
them from the system but that made no difference in the cars
performance. I still feel its notable, since they've undoubtedly been
applying more stress to the alternator and voltage regulator.

The other thing I'm terrified about is that it could be a short. I've
already replaced a bunch of wires with degraded insulation, but I
wouldnt be suprised if there are more. Still, the problems dont seem
symptomatic; I'm not blowing fuses.

I really havent the foggiest idea whats going wrong. I had my battery
checked and NAPA told me it was ok. Still, these problems started not
more than a day or two after I left my headlights on + needed a jump
start. On the other hand, I have been stressing the power supply
system in my car a little more than normal. If anyone has thoughts for
what to check, what to try, whats going wrong, I'd really love the
help.

Thanks
-Rektide

 

[Randy G.]

You had the battery checked, but did they check the charging system?
Could be an alternator or regulator. Sears use to do that for free.
Don't know if they still do.
Also, check the battery cable connections at both ends of both cables.
Loosen and tighten all four connections and clean the battery
terminals and clamps. Run your hand along the length of both cables-
check for stiff or swolen areas that would indicate that the cable
needs replacing.
Feel the fuse panel and local wiring for any that are abnormally warm.
If it was a short then the related wire would be melted.

Hello all,

I'm on the road and my 240DL has started giving me serious power
problems. Turning on anything electronic reduces power from the rest
of the system; the car just stopped being able to keep up with the
power demands. For example, hitting the brakes causes the lights to
dim. Turning the climate control fan on dims the lights- every step up
brings quite a noticable drop in brightness. Also, high beams get
stuck on, I have to turn the lights off, flash my high beams, and then
turn my lights back on to disenguage high beams.

I've been running a 300 watt 120v inverter and a decent sized stereo
for two weeks now off the system. They tap onto the positive terminal
of the battery, and are grounded onto the chassis; I've disconnected
them from the system but that made no difference in the cars
performance. I still feel its notable, since they've undoubtedly been
applying more stress to the alternator and voltage regulator.

The other thing I'm terrified about is that it could be a short. I've
already replaced a bunch of wires with degraded insulation, but I
wouldnt be suprised if there are more. Still, the problems dont seem
symptomatic; I'm not blowing fuses.

I really havent the foggiest idea whats going wrong. I had my battery
checked and NAPA told me it was ok. Still, these problems started not
more than a day or two after I left my headlights on + needed a jump
start. On the other hand, I have been stressing the power supply
system in my car a little more than normal. If anyone has thoughts for
what to check, what to try, whats going wrong, I'd really love the
help.

Thanks
-Rektide

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

[James Sweet]

Hello all,

I'm on the road and my 240DL has started giving me serious power
problems. Turning on anything electronic reduces power from the rest
of the system; the car just stopped being able to keep up with the
power demands. For example, hitting the brakes causes the lights to
dim. Turning the climate control fan on dims the lights- every step up
brings quite a noticable drop in brightness. Also, high beams get
stuck on, I have to turn the lights off, flash my high beams, and then
turn my lights back on to disenguage high beams.

I've been running a 300 watt 120v inverter and a decent sized stereo
for two weeks now off the system. They tap onto the positive terminal
of the battery, and are grounded onto the chassis; I've disconnected
them from the system but that made no difference in the cars
performance. I still feel its notable, since they've undoubtedly been
applying more stress to the alternator and voltage regulator.

The other thing I'm terrified about is that it could be a short. I've
already replaced a bunch of wires with degraded insulation, but I
wouldnt be suprised if there are more. Still, the problems dont seem
symptomatic; I'm not blowing fuses.

I really havent the foggiest idea whats going wrong. I had my battery
checked and NAPA told me it was ok. Still, these problems started not
more than a day or two after I left my headlights on + needed a jump
start. On the other hand, I have been stressing the power supply
system in my car a little more than normal. If anyone has thoughts for
what to check, what to try, whats going wrong, I'd really love the
help.

The place to start is the alternator, pop out the regulator/brushpack and
look at the brushes, if they're worn replace the assembly. Also check the
ground wire from the alternator.

 

[rektide]

Thats definately my main suspect. I'm thinking I'll probably try to
just replace the whole unit with a GM SC-130, there's a couple people
who've done that, they're good to 140 amps, some up to 200 A. That
would be swell.

Rektide