I have a 1993 Del Sol Si D16Z6. About a week ago I noticed that the battery light would come on, and I would suddenly get a power surge to all my electronics (all the lights became brighter and the heater fan blew stronger, windows went up and down faster). This would only last until the light went off then everything went back to what I assume was normal. Sometimes this was associated with a belt squeal but not always. Today same thing happened only the light has stayed on along with the excess power. I'm assuming this is an alternator problem but based on the power surging I think maybe there is some sort of voltage regulator that is bad. Any info on this is appreciated.

 

Coincidentally I just replaced the alternator in my 93 del sol si this week.
I got 220 k miles. My battery light was coming on and off for the past month. I tried cleaning the connections ( harness connector and the thicker power wire to the fuse box). But it was time. The voltage regulator is mounted to the back of the alternator. When the light was off and the battery was charging I got about 13v on my meter across the battery terminals. Should get 14 to 15 volts with a healthy alternator. I got a better than average replacement alternator because the effort to replace the alternator is involved. You have to remove the drive axle on the driver side to take the alternator out thru the bottom.

 

Is that the only way to get the alternator out? What I don't understand is why I seem to get more power rather than less power when the battery light comes on. I'll see what my multimeter gets when I get home (if I get home).

 

Well today I didn't have the problem at all when driving. Although after the last power surge now my drivers window won't work. All the others still work. Anyone have any ideas? This is not just an "alternator is weak, replace it" problem.

 

Voltage regulator is most likely bad and the alternator is overcharging.

For what it's worth I've had a few alternators die and the only times I've ever seen the battery light come on was when I had a bearing go bad and the alternator seized and burnt the belt off, and one other time when I had one overcharging putting out about 18v at idle. I've never seen the battery light come on for one that's undercharging or not charging at all.

 

Ok, this is what I was thinking. At the moment the problem has stopped but to prevent future calamity I'm going to replace the voltage regulator. Has anyone replaced just the regulator or should I replace the entire alternator unit?

 

The regulator is part of the alternator, they are replaceable but if it's a Mitsubishi alternator and you live somewhere where it snows good luck ever getting it apart without destroying it. Sometimes you can't even get them off the car in one piece. If it's a Denso they're A) a much better alternator that's worth trying to fix and B) you can actually get them apart to replace the regulator.

 

Ok, the rabbit hole has gotten deeper with this problem. As soon as the issue stopped happening I noticed that my driver's side window wasn't working. Looked at the fuse (#8, 20A) and it was blown. Window worked perfectly after that. Then I tried to start that car. Got a flicker from every light on the dash and a rapid click sound. I stopped trying to turn the car over. I tried a second time and it started right up, but the driver's window didn't work again. Pulled the fuse and yup, burnt out again. I took the car to an autozone to get the charging system tested. It said 100% battery charge, 12.6 V, but bad battery? When the car was started it read 14 something and that the alternator was working fine. Could this all be from some sort of battery issue??? Also my passenger headlight isn't working, haven't checked that fuse but I assume it is blown as well. Major headaches. Anyone have any insight into this? I hate to just throw parts at this without understanding whats going on. Any idea why fuse 8 in particular keeps blowing?

 

If you don't immediately replace the bad alternator you risk destroying all the sensitive electrical components in your car.

 

Strange electrical issues are typically related to ground problem or shorting wires.

My first thought was lose ground, start by checking your battery ground and battery connections.

Next, you have a blown fuse and it has blown again + random electrical problems. You likely have a short. Check any work you have done recently.

 

You may want to explain how an overcharging issue would be caused by a bad ground.

 

I don't follow?

No overcharging issue has been diagnosed.

 

 

Without recording the voltage it's nothing more that a perception of the situation. I have had similar happen when a wire rubbed through on a bracket and threw a speed sensor code (common problem). My lights surged and had all sorts of dash lights flashing all due to shorted wire.

More recently was a loose ground on my bosses wife car, she threw a code for EGR and even had it replaced before I found a loose battery cable.

Electrical problems can do all sorts of crazy things, always start with the easy fixes.

 

Voltage readings are needed but the comment below makes over charging highly likely:

 

I'd say you've got a bad alternator pal... Alternators do some pretty interesting things when on the way out the door. Ive seen bad E.L.D's do weird things to but I doubt that's your culprit. Try checking voltage with the engine running at the alternator with a good body ground and let the car run for a while looking at the multi-meter. See if you get any spikes or drops. Oh... and cross your fingers that you car didn't get struck by lightning... I've seen two that have been and they too did some wild things.

 

Ok, I think I need to clarify a little more. What originally did seem like an alternator problem has changed. Ever since that fuse blew the car has ran without any issue or power surge. An the issue I had when starting the car happened without the engine even turning. There is more than just a bad alternator here. It may be possible that a bad alternator caused another electrical problem but now it works perfectly? Does anyone know more specifically what is on fuse #8's circuit so I can check some wires?

 

Remove fuse 8 and don't install a new fuse until you repair the short in the passenger window motor circuit.

With the fuse removed, take the car for a drive. Post any problems you noticed.

It seems you were told the battery was bad. Did you replace it?

 

So I've driven the car for two days now without that fuse now absolutely no problems and no battery light. I have not replaced the battery yet as I'm still trying to rationalize what happened and why that fuse blowing seemed to make everything go back to normal. No starting issues, no charging issues, mutli-meter shows no spikes when charging. The tester at autozone said the battery was bad, and admittedly I don't know exactly what this tests or looks for but I assume it runs some sort of current through the battery to check the cells. Would it be possible that a failing battery cell caused the power surge which caused a separate issue (the driver's window short) but has now corrected itself now that the cell is dead? I'm just trying to wrap my head around things before I start replacing everything. I'll start chasing wires in the door soon to find the short.

 

If the battery test was done properly and indicated that the battery is bad, then the rationale for replacing the battery is self evident.

As I stated, fuse 8 protects the passenger window motor circuit. Use your multimeter to pinpoint the short to ground and fix it. Then go from there. The only way that the shorted window motor circuit would cause system problems is if a higher than required rated fuse was installed in the fuse 8 slot.

 

I must have a variation in wiring because this fuse definitely controls the driver's side window. The passenger window works well and has no issues. I was thinking more that the short was the result of the original system problem whatever it was and not the problem itself.

Thank you for the help. Hopefully I won't have too much trouble finding the short.

 

Hmmm...maybe a difference between the Del Sol and Civic.

 

The Del Sol circuit for the power windows turns out to be very different from that of the Civic:

 

Here is an update for future searchers. The problem was in fact caused somehow by a failing battery. Once the battery was replaced the car has driven fine without any issue. How a failing battery caused the power surges I can't exactly explain but it's been months now and no new issues. The power surge caused two secondary issues which were my passenger side headlight burning out (just needed to replace it and it worked fine) and fuse #20 blowing which inactivated my driver's window. This fuse still consistently blows and I have not found where the short is yet. I'm hoping it is not internal in the window control module.

 

I have a 1993 Del Sol Si. A few months ago I had a power surge from apparently a failing battery that blew out a headlight (replaced, now works fine) and inactivated my driver's side window. After replacing the battery I checked the fuses and saw that #8 (20amp) was blown. I replaced it and the window worked. Started the car, drove around, then window didn't work anymore. Pulled the fuse and it was blown. I put another fuse in to see why it didn't blow right away and whether or not starting the car affected it. When I put the fuse in this time and turn the car to on the fuse did not blow but the window would not work. It would however sporadically make "twitches" up and down. Using the switch might make it more frequent but doesn't do much else. Turning the car on does not blow the fuse either. Rather than waiting any longer I just pulled the fuse. The passenger window and rear window all work perfectly. It doesn't seem to be a simple short and I'm worried that the power window control module is bad.

I've searched but there is not a ton of information on this thing other than it is a common problem, so I have a few questions

1) Is there an easy way to get to it? I know it's behind the stereo but do I have to take apart the dash or can it be access from the foot wells somehow?

2) Does anyone know how to test it with a multi-meter?

3) Could it affect just the driver's window and not the others?

Thank you for the help.