Problem with Dash Lights

[MatthewRyan318i]

Hey,

I was hoping everyone could pull together to help me out. I have a 1985 BMW 318i. When I'm driving at night my dash lights in my Instrument cluster keep on dimming lighter and darker. (Speedometer-RPM's-Gas/Oil Gages...etc.) They will be bright one moment and darker the next. My stereo is working fine and so is my heater. Thanks for everyones help.

,Matthew

[Sniper]

your system is drawing too much of the current so the lights go dim.......what kind of alternator(how many amps is it)?......

[pr0ject TRUENO]

Relay switch perhaps?

[MatthewRyan318i]

Originally posted by blindarrow
possibly.

do you have any problems with your battery going dead or anything? does your car take a little longer than usual to crank?

you might have a draw somewhere.



what do you mean by draw?

[Iceman_19]

did you check all your fuses? anything with electrical, first thing you should do is check your fuses. does it dim when your stopped, or while your driving, or both?

[pr0ject TRUENO]

Hmm...not sure if it would be a parasitic draw, but you can test that. Close and turn off everything in the car (doors, lights, etc) and open the hood. Remove the ground cable from the car and attach a test light or ammeter from the post to the cable itself. The light should be off or the reading on your ammeter should be less than 50mV. Sorry if you cant understand this; it's the easiest way to put it that I could think of.

[Sniper]

while you're at it.....check to see 12V between the terminals.......

[pr0ject TRUENO]

Or 12.6, whatever. But I doubt it's a parasitic drain; if it was, then your car wouldn't start in the morning and you would have to jump it every day.

[pr0ject TRUENO]

It's most likely the relay; they're not designed like fuses. Even if your relay becomes bad, it's designed to stay on, which causes the intermittent on/off signal.

[MatthewRyan318i]

I just wanted to say thanks for all the suggestions and if you have more keep them coming. I'll start trying what everyone has said and i'll get back to you all. I wanted to clarify that my dash lights just get darker and brighter, they never really go out they just go really dark to where it's hard to see then, but at times they are very bright. Thanks again everyone and if anymore suggestions just post them.

,MatthewRyan318i

[MatthewRyan318i]

Sniper my alternator is a Bosch, and it is reading 15-16amps.

[Sniper]

HOLY SHIT!...that's the problem then.....your alternator is dead........you should probably have ATLEAST an 80-85A alternator in there........

[MatthewRyan318i]

LOL, my bad i meant to say 15-16 volts, the amps I have no idea about

[Sniper]

hell, that's just as bad....shouldn't be reading any more than mid 14's....sounds like your regulator is shot.....damaging the battery and causing the lights to get brighter or dimmer during surges ....take it to AutoZone or something where they test alternator and batteries free........

[MatthewRyan318i]

Once again my mistake, it wasn't 15-16 it's 14-15, and I would ruler out the voltage regulator because I just bought a new one.

[333racer]

hey matt i'll help ya out here, get some more info out to the guys.

ok correctme if i'm wrong, but he just took a reading of his battery and it registered at 11.43 volts. so i'm gonna assume there is a draw somewhere right BA??? anyidea on how to source it quickly? or should we just turn off all the power and just start checkin each wire that has a switch??

[pr0ject TRUENO]

Follow the directions for my parasitic drain test.

[333racer]

Originally posted by trBo432-R
Follow the directions for my parasitic drain test.

that tell's us if his car has a draw, but then how do we find where the draw is coming from?

[MatthewRyan318i]

Well everyone your hard work has payed off, and for that I'm very greatful. I've come to the conclusion that my alterntor is the problem. As I said before in the thread that I had a problem with my car dying at night with my headlights on. Well we replaced the battery thinking that I had a couple dead cells that wouldn't let the battery recharge. Well it's actually the alternator that isn't letting it recharge. I'll explain it like this, like a power plant it supplies power to houses, well once it doesn't have enough push to power the house it starts loosing it's power it's self, which takes power away from all the other houses that it was powering before, so what i'm saying is my alternator is just damaged enough to where it doesn't have enough push to recharge my battery creating everything including the battery to die. Which is why I'm still having problems with my dash lights right now. Once again thanks for everyones help it was great to know that I can come here to get help. Thanks and God bless.

,MatthewRyan318i