Electrical problem

[PhilC]

Electrical problem (charging at 16volts)

I seem to have an electrical problem and I was hoping that someone here may have experienced something similar so that if shared they could save me some time and frustration.

Headlights change in level of brightness, dash lights flicker, water/**** indicator light is coming on and flickering (when not under boost it shouldn't come on at all). The charging system gauge is pinned at 16volts (it's not the battery or the alternator, they're both new).

I know that's clearly not enough information to diagnose the problem unless of course someone has experienced the same set of problems.

I'd be happy to answer any questions which may prove useful in tracking this problem down.

Thanks in advance for any help

Phil

 

[dave6666]

Who did the work on the new battery and alternator?

Are all of the wires tight?

 

[PhilC]

All the wires I have checked so far seem to be tight and well connected. It went in for this problem so it is not likely related to the work done.

 

[93Cobra]

Could it be a voltage regulator? Just wondering and not sure if the Viper even has one. I remember this beind a problem on one of my BMW's.

 

[luc]

Sound like a bad ground connection.
Double check the connection between the battery - post and cable and the cable and grounding point on the frame.
Check the negative battery cable for any problem, if you have jumper cables attach 1 end a of one the cable to the negative post and the other end to the frame
Try a diffrent battery, sometime you can have a bad connection between the posts and the plates.

Luc 00GTS

 

[PhilC]

I wil try the ground although I don't think it is the problem. As far as Voltage regulator, I believe it is actually inside the pcm.

An interesting side note, hopefully of some value, two nights ago when it was in the dyno shop (nice 70 degree temp) it was not exhibiting this symptom according to my tuner who I trust completely with my car (the only one I might add) and last night while driving it home in the extreme cold in the snow it was once again problematic.

So the question becomes is there any component related to the charging system which might be temperature sensative or if faulty could produce this symtpom in the cold but not warm weather?

 

[99 R/T 10]

What year is your car? I had a 96 RT/10 and when the headlight switch went bad(known problem on the Gen I cars), it exhibited the same symptoms.

 

[dave6666]

Batteries are temperature sensitive. Modern technology has addressed that to some degree, but extreme cold or hot weather is not battery friendly.

What brand of battery did you get? If you are going to reply Optima, do not post any further until that POS has been replaced!

Voltage regulators are either integrated into the alternator itself, or as you stated, maybe the PCM. Looking at the wiring diagram on my '01 GTS, the field current for the alternator comes from the PCM, suggesting it might be regulated from there.

And if the tuner is the only one you really trust with your car, then who did the battery and alternator replacement...?

I would lean toward a ground or battery issue from what you have said.

 

[luc]

There is a battery temperature sensor that adjust the regulator output depending on the battery temperature but I really doubt that it is the problem.
2 things points to a bad connection/battery, the voltage regulator put out 16 volts and you still have lights flickering and change in headlamps brightness.
.
That's mean that the voltage regulator sense that the battery is low but also that the lighthing circuit get spikes in voltage

 

[PhilC]

My tuner did the alt and bat. I will try the things suggested here but it's looking like it may be the pcm itself. I'll also borrow a pcm and try that. Thanks for the input, I will report back my findings.

 

[Vic]

Where does the water/**** "on" switch get its voltage from? Look in the fuse box, and see how its wired. I saw a car once where a wire was just shoved into the female fuse terminal along with a fuse, instead of being properly terminated. Maybe there are wayward strands of copper touching adjacent terminals, dragging some volts to ground. Does the problem occur during periods of vibration, like when you drive over railroad tracks?

 

[PhilC]

The water/**** signal is directly from the vec 3 and the connection is good. Iwas try to determine if there was any pattern to when it occurs (such as vibration) but it does seem to. Thanks for the input.

 

[PhilC]

What year is your car? I had a 96 RT/10 and when the headlight switch went bad(known problem on the Gen I cars), it exhibited the same symptoms.

I missed this post. Thanks for the info I will test the switch this weekend. Wont have time tomorrow.

 

[PhilC]

OK, I replaced the pcm with a loaner and the problem is not the pcm (it still occurs with the loaner pcm). Wiring seems good (at least that which I can check readily).

Question regarding the headlight switch, would it be reasonable to assume that if I pull the fuse related to the headlight circuit that I have removed the switch from the equation or do I physically have to remove the switch?

 

[dave6666]

OK, I replaced the pcm with a loaner and the problem is not the pcm (it still occurs with the loaner pcm). Wiring seems good (at least that which I can check readily).

Question regarding the headlight switch, would it be reasonable to assume that if I pull the fuse related to the headlight circuit that I have removed the switch from the equation or do I physically have to remove the switch?

I just looked at the wiring diagrams for my '01 GTS. The circuits are a little more complicated than just a fuse.

There are these items:

(2) fuses from PDC to switch
Fog Lamp Logic Relay in PDC
Low Beam Relay in PDC
Headlamp Beam Select Switch on steering column
Key In Switch/Halo Lamp
Panel Lamps Dimmer Switch
Driver Door Latch Switch
EEM Key In Ignition Switch Sense
(2) more fuses to other stuff

All that is what is connected to the headlight switch.

You can probably pull a lot of it w/o killing anything unneeded.

 

[PhilC]

Thanks Dave. That's a whole lot more than I realized. I think this just got past my ability level. It's not that I an unwilling to put in the effort, I just dont seem to have a lot of talent in this area. I was hoping to get this sorted out this weekend but now it seems that I'll have to bring it to the tuner for him to sort it out.

 

[rogerdarabbit]

What was the solution to this problem?

 

[justingeer82]

im certain its a bad ground. simple thing to do is to remove your fuses one by one and add a bit of dielectric grease to each one and insert. youd be amazed how many vehicles i have fixed within a few moments of working on them just by them having bad grounds or corroded terminals for the fuse block.