BAFFLED about my dimming lights and Seatbelt indicator. PLEASE ADVISE IF YOU CAN!!

[jbripps]

Hi all,

Again, as many of you know already, I'm not a DIY guy, but I'm gonna try to take care of this one myself (at least the diagnosis). It seems that when I drive at night, quite frequently, my seatbelt indicator light will come on for a few seconds or so. When this occurs, I notice that my headlights shine much brighter. When the light comes off, the lights dim back down (to normal I guess?). Additionally, When the seatbelt light comes on in the day, I notice that half of the stereo speakers cut out until the seatbelt light goes out again. By the way, it also happens at night too. It seems that this happens randomly and doesn't have much relation to RPM's, braking, etc. DOES ANYONE HAVE ANY INPUT HERE! IT'S DRIVING ME CRAZY. Just a guess, but could this be related to the Alternator?

Thanks a million fellas,

JON
'85 targa

[david c.]

Hey, I'd like to know why my seat belt light comes on periodically for no night also! My lights don't dim, but the buzzer goes on for about five seconds, then that's it. WTF?

Dave

[Jorgeman]

My guess would be a failing voltage regulator which is part of the alternator. Your lights getting brighter indicates a higher voltage at that time. The alternator is capable of 17 volts when the regulator isn't 'regulatin'!


George 86T

[twin plugged targa]

I'm with George on this one!.
Alernator!.
Also check that someone has not over tightened the fan shroud which would cause rubbing on fan blade and slow alternator.
If you alternator is suspect.
CHECK YOUR BATTERY! for overcharging and boiling over!.
This is very important and could save you $$$$$$$ in the long run!.
Good idea to check your battery condition periodically.
911 alternator seem to be problematic passing there woes onto other systems and components!
Beware the dimming light!.
How do I know?
New alternator, battery and cut out rust and replace area around battery total around $2,000!.
Hope this helps
rgds Ben

[jbripps]

Hey guys,

You seem to be right so far. My wrench concurs with you. Battery seems fine, as the problem only occurs a few seconds at a time, and is not constant. Also, my passport radar detector has a volt meter built in it (pretty cool, but I don't want to start that thread again), and when the light comes on, the meter reads "high voltage". The only place I wish to see this again is on the AC/DC album cover. So, I guess it's time for my baby to visit someone else's garage for a day or two. If anyone has other input or advice, I certainly would appreciate it. THANKS AGAIN ALL.

jon
'85 TARGA

[nhromyak]

John Walker posted the seat belt light comes on (atleast for the Carreras) when the voltage is too high. I didn't ask him why though.

At any rate, my voltage regulator died out too. I got an Optima battery (just in case), let me tell you the OPTIMA batteries do indeed LEAK when they are overcharged.

I got acid gel splatters all inside my battery compartment. Check yours for acid spill and clean as appropriate.

My biggest giveaway that I had a bad alternator/regulator, was when my radio amplifier blew out.

Good Luck

------------------
Nick Hromyak
'85 Carrera 7 & 9 Fuchs
Havin' Fun in Sacramento

[Eric Coffey]

I would say without a doubt that it is a bad voltage regulator putting out 17V. I posted this exact question (with your exact symptoms) and John Walker advised me to look at the voltage regulator. Sure enough, it was putting out 17-18V intermittently. One good way to test this is to get an old cigarette lighter adapter (like from an old cell phone) and make a test lead out of it. All you do is chop the phone end, find the + and - , and crimp on "banana Plugs" or any other connector type that will fit in your multi-tester (you do have a multi-tester right!). Then, with it hooked up in the car, you can view your cars voltage output in real time. If it ever jumps to 17V, you have your answer. If you are going to be pulling everything out, I would urge you to just replace or rebuild the whole alternator, not just the regulator. Just an opinion from a guy who just went through the same thing you are about to!

-Eric

[jbripps]

Eric,

Thanks for your input. It seems that I do have a voltage jump. I'll double check the battery. Is this safe to drive with for now? I've got a 5 hour trip tomorrow, and was hoping to take the P-car. Did you fix the problem yourself, or did a wrench give you a hand? What was the total damage? I know the alternator had to be yanked, which can take 2-3 hours all together? THANKS,

jon

[Eric Coffey]

Jon-

Well, I did the whole job by myself, and it was fairly simple. The total investment included a new (rebuilt) alternator which had the built-in regulator, and a new alternator belt, and about 3 hours of my time. The alternator and belt cost me under $200. The procedure goes as follows:

First, disconnect the battery. You might also want to check around the tray area to see if any acid leaked out. Then you can start the endeavor by loosening the A/C belt tension screw and bracket bolts to remove the A/C belt. After you have the A/C belt off, you can get out the fan spanner wrench and remove the pulley nut, shim sleeve, shims, and alternator belt. Be careful not to drop any shims! Next remove the plug wire keepers on top of the fan housing, then loosen the fan strap retaining (hex) bolt. You may find it easier to remove the plug wires from the distributor cap, but it is not necessary. Next, pull the fan housing out slightly to expose the rear airflow "director" mounted on the back of the unit. Remove the 3 (8mm?) nuts and slide the "director" back off of the fan housing. Now you can unbolt the connectors from the back of the alternator, and remove the entire fan housing. The next trick will be to get the fan off of the alternator shaft and the alternator out of the fan housing. The easiest way for me was to gently "wiggle" the fan off after spraying the shaft with WD40. There will be a little "key" that will fall out, that holds the fan in place by a slot on the alternator shaft, so be sure not to lose it! With the fan off, remove the remaining 3 nuts that secure the alternator, then stack up about 6 or 8 pieces of cardboard on the garage floor, and forcefully (but not brutally) tap the rim of the fan housing on the stacked cardboard. Do this a few times, then rotate the housing 180 degrees and do it a few more times, repeating the process until the alternator falls free. Everything goes back in reverse order. Then when you get to the point where you need to put the belt and pulley on, you will need to use the shims to set the belt tension. For me I only had to use one shim in between the pulley "halves", but they are probably all different. Make sure you store any unused shims on the outside of the pulley, or else the fan nut might not tighten all the way.

If you do decide to tackle the project yourself, I commend you! Let us all know, and I am sure we will be able to give you pointers or advice along the way (that is why I love this board!). Wow, I can't believe I just wrote all that!

-Eric

[MDrive]

Be careful about long trip on a battery that is being overcharged. You can overstress the battery, boil out all the electrolyte and expose the cells which will either drain the battery to the point that you cant start the car or make it blow up. If you still do plan on driving it, either have another battery handy or carry some distilled water with you to add to it. Don't ask me how I know this. Good luck.

Mike
86 Carrera

[jbripps]

OK everyone, thanks so much for your input. Voltage reads too high when the seatbelt light glows. Also, have found out that voltage is too high at times, without the light coming on. By the way, roadtrip was amazing, and no overcharge occurring. The car will be going in for a Voltage Regulator soon enough.

One other thing, I notice that when the voltage is high, that when my RPM's are around 3000 or higher, that a loud sqeaking comes from the engine. I think it is from a pulley or belt, but I can't pinpoint it. When the voltage goes back to normal range, the squeaking will cease. ANYONE KNOW IF THERE IS A RELATIONSHIP HERE? I'm Baffled once again. Is there a way I can address this? WD-40? Where? ANY ADDITIONAL INPUT WOULD BE GREATLY APPRECIATED HERE. THANKS SO MUCH.

JON