# Few problems - '98 Altima GXE



## Akirhol (Aug 30, 2006)

Had the car for a little while now, and only recently has it started to exhibit abnormal behavior. 80k miles, automatic, daily drive with no mods... here are my issues:

1. There are times when the RPM gauge seems to fluctuate more than it should while driving, almost like it's twitching. This is especially true in the morning on my way to work. Also, when first starting it, I can sit in neutral and rev up to 2k and keep it steady, then it will suddenly rev itself up to 3k or down to 1k, seemingly at random. Engine performance doesn't seem to be affected, but I'd still rather know what it's doing and how to make it stop. My first thought here is the TPS, but anything else I should check while I'm at it and/or if that isn't it?

2. The dash and shifter lights are out, just noticed this a couple of nights ago. Luckily I keep a flashlight in my glove box so I can keep an eye on my speed... end of the month, all the cops trying to get their quota in. =P Anyways, I can't figure out where the fuse is for these lights, I've checked the fuse box next to the battery and under the steering wheel... anyone else know for sure where it is?

3. Speaking of fuses... while looking for the dash fuse, I found the problem I had been having with my stereo not working, a burnt audio fuse in the box next to the battery... didn't know there were two [one in the box under the steering wheel as well]... so I fixed that, but now my stereo continues to exhibit the behavior that it did before it went out last time, mainly a flickering display [the button lights still work fine]. Any ideas here?

It's worth noting that my alternator is on the fritz, or so it would seem... for awhile I thought the battery wasn't holding a charge but once my radio died and my subs weren't drawing power it started holding a charge fine again. So I'm thinkin it has to have something to do with the alternator, but my experience isn't too fleshed out so maybe it's something else? And if it is the alternator, could that be behind my other issues, maybe blowing the fuses? I'm pretty clueless when it comes to the electrical system, but I'm trying to learn. :newbie: 

Oh ya, almost forgot to mention, no CEL but I haven't checked for any error codes yet... I need something I can do that with first, heh. Can the computer kick out error codes but still not flash the CEL?

Thanks ahead of time for reading and maybe even responding... kinda sucks that this had to be my first post, but hopefully I can get these resolved and have my DD back to normal operating conditions [and hopefully keep it out of a shop].


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## Darktide (Jul 29, 2004)

Autozone will get you a long way on this car. They will check your codes for free. They will test your battery and your altenator for free as well. Start off with that. If you fix those things, or everything comes out ok, check for vacuum leaks. I would start around the valve cover and intake manifold. You're probably onto something with the TPS sensor but its really simple to test for vacuum leaks. Just spray some carb clean around the intake manifold and valve cover while the engine is running and if you hear the idle race then you'll have found the vacuum leak. I'll check my haynes manual tonight at work and get back to you in the morning if I find out about the dash light fuse. But the stereo... if its stock... chances are its just dead or dying. They aren't the best or most durable. You can find'm on eBay pretty cheap. Good luck and I'll see what I can find.

Darktide


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## Akirhol (Aug 30, 2006)

You know, it would seem natural for me to forget something and I did... while driving, I will often hear a hiss that sounds like compressed air being released somewhere but only happens on shifts, usually shifting up while accelerating. Would this support the vacuum leak theory? Now that I think about it, that sounds like it would be related.

The radio isn't stock, but it's a dual, the lowest end radio I could find that had pre-amp output for the subs... I didn't install them, the previous owner did, but I figured I'd at least get some use out of them as long as they're back there. I wouldn't put it past the radio to be dying, I never intended it to be a permanent deal anyways. I was just thinkin maybe that had something to do with the blown fuse in the first place. *shrug* 

I'll look for the nearest autozone, should be one or two in OKC. Thanks for the reply Darktide.


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## Darktide (Jul 29, 2004)

ok, Dual = big pile of dung.... but it seems like you know that

I wasn't able to find the time during work to check out the haynes manual. I had a few managers on my case about stupid stuff. 

But the vacuum leak seems to be a thing to consider at this point. But normally you can't hear them unless they are rather large. Definately go to Autozone and have'm check out the altenator, battery, and CEL just in case. Good luck with it

Darktide


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## amyter (Apr 5, 2006)

RPM gauge seems to fluctuate more than it should while driving.
I had this problem, check the wire that goes to the sensor (left side of the engine) it was loose at the connection, i carefully hit it with a flat tool in the head to thight it and that´s it, it works now perfectly.


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## kwade (Mar 22, 2007)

Just a question... did you ever find out about the dash lights? I'm having the exact same problem, and haven't found similar experiences anywhere else. BTW... my husband found some lights that plug into the cigarette lighter and attach to the steering column to light up the dash at night. Much easier than using a flashlight or cell phone.


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## Ryan's Altima (Aug 29, 2006)

I had my dashlights go out on me a few months ago. I moved the dimmer switch back and forth for a couple minutes until it came back on. Instead of moving it to full brightness I moved it just a bit dimmer so I couldn't even notice it. Its been working fine so far, my guess would be that there was some buildup from it being in that position for such a long time. Hope this helps


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## AltimaBlues (Apr 6, 2006)

*Dimmer switch is very repairable*



Ryan's Altima said:


> I had my dashlights go out on me a few months ago. I moved the dimmer switch back and forth for a couple minutes until it came back on. Instead of moving it to full brightness I moved it just a bit dimmer so I couldn't even notice it. Its been working fine so far, my guess would be that there was some buildup from it being in that position for such a long time. Hope this helps


Dash lights went out on 98 Altima last week. I pulled out the dimmer switch unit. It is fairly easy to disassemble. The circuit is also simple. The thumb wheel is actually a 10 position switch which has wipers that move through some grease on the printed circuit board. I replaced the burn out indicator lamp with one from Radio Shack (#7219 micro lamp). 
The circuit is a pulse width modulator. The components most likely to fail are a LM2903 dual comparator (of which only one side is used), an IRFZ20 N channel MOSFET which handles the load current of all the lamps which are dimmed, and a 22uF 25V electrolytic capacitor (this is probably the weakest link). All the rest are surface mount resistors and a few ceramic capacitors.
I cleaned up some of the grease, and after replacing the indicator lamp, the unit worked fine. Have a schematic that I generated for those who are interested.


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## I'm3rd (Dec 24, 2003)

AltimaBlues said:


> I cleaned up some of the grease, and after replacing the indicator lamp, the unit worked fine. Have a schematic that I generated for those who are interested.



My dash lights got to the point where they would only work on full bright or so dim they were useless. I simply rolled the little wheel-type control on the lower left dash up and down rapidly for about a minute and it now works all the way from very dim to full bright. It flickers a little on some of the mid-range settings but I can move it a tiny bit up or down and it takes care of that.


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