Need help with electrical problem

**kool-aide** · 12-03-2007, 04:50 PM

I washed my car on Sunday, and washed the engine bay too.

On the way to work a few of my gauges when nuts on me.

The last time this happened it turned out to be a loose alt wire / connector.

What happens is while I drive the alt / bat gauge goes red on the 18 side and various lights come on, like air bag, abs, asr, brake.

I even had the A4 downshift and then up shift on its own, never does that.

When i drive you can see the gauge needle bounce, doesn't matter hwat speed.

If the lights are on you can see them dim and bright in a pusle, like the gauge

radio is fine, windows are fine, starts fine, drives fine.

I've washed my car and engine area before with no problems. The only thing I did different is use a degreaser first, that orange smelling stuff greased lightning in an orange bottle. It was either buy that or simple green cuz those were the only two that didn't have don't use on aluminum warning.

I also washed the under side of the car. I know that the electrical housing on the start is busted and exposes the insides. The car starts fine so i think the start is still ok.

What could be wrong? I pulled and re-chekced the atl connector, no luck. This one has me stumped.

thanks

kool-aide

**sunsetorangess** · 12-03-2007, 05:21 PM

Recheck your alt connections and battery connections, also you said your starting housing is cracked, Is it possbily arching? Also check your fuse box to ensure its not soaked and all the degreaser has been removed.
J

**kool-aide** · 12-03-2007, 05:25 PM

hmm, i overlooked checking the fuse box. now its been a day and a half, would the degreaser be dry? I doubt the starter is arcing. besides once the car is running wouldn't the start be out of the pic? Who knows. I am going outside right now to check the fuse box.

**sunsetorangess** · 12-03-2007, 05:28 PM

Well You still have power going to the starter so if theres water in the housing then bad things could happen. It should be dry but its something to check. Also make sure your battery and alt connections are good and tight.
J

**blue02Z** · 12-03-2007, 06:00 PM

i would pull all the alt. connections and unhook the battery. let it sit, clean em and hook it back up, check your ecu connections, make sure they are not all wet

**kool-aide** · 12-03-2007, 07:02 PM

well now what ever i did has the fans running on turbo. Now it sounds like a mini turbo prop under the hood. Oh boy, its just one bad thing after another.

I pulled the battery cables and atl connection.

I tried reseating all but the really big square fuses.

The starter is gunna have to wait until the weekend, cuz I hate taking that on and off.

well i'm just going to have to limp to work and back tomorrow and try again tomorrow afternoon. I have no clue what could be the problem. Specially now that the fan or fans are acting up.

i think my car hates taking a bath. maybe it didn't like the brand of chrome polish i picked out.

thanks

**0rion** · 12-04-2007, 01:03 AM

I thought I recognized you. http://www.ls1.com/forums/showthread.php?t=69103

This is why I say NEVER to use a hose on your engine. Cars today aren't like cars 30 years ago. There's a ton more electronics on todays car than in the 70's when you just had to worry about the distributor. Anyhow, don't mean to rub it in but I figured before to long you'd be making this post.

How wet did you get the pcm? It has water tight connectors on it but rubber ages over the course of 8 years. I would start at the fuse boxes and just hit them with a hair dryer and hope you can get whatevers wet dry. My understanding of the instrument cluster leaves a lot to be desired and if someone can enlighten me I'd appreciate it. The cluster gets it's info via serial data cable. What I'm not sure of is how voltage is effected through that cable. That's why I was curious how wet you got the pcm.
Since you mentioned the starter I would definitely put that on the "to check" list. Bad grounds are a pain to trace down. The good news is that it'll mostly likely dry up on it's own at some point in time if it is a water problem. It could just be coincidence that this happened when you washed the engine but I'm betting it's directly related. I see to many of these threads where people have these problems after washing the engine.
Now, watch 2-3 people will post up that they wash their engines all the time with zero problems. 6 months from now they'll be posting up electrical problems after washing the engine bay.

**blue02Z** · 12-04-2007, 04:08 AM

i'm leaning toward the pcm, you prolly blasted the hell outta it and didnt even realize it

**Sarge** · 12-04-2007, 04:10 AM

I dont use a garden hose on my Desktop PC nor my engines. Call me silly.....Simple Green and some rags will clean your engine bay really well....I suspect you toasted your PCM and electronics.....

**Orcus79** · 12-04-2007, 12:37 PM

I wouldn't be so quick to say that the electronics are fried The voltage reg in the Alt could have taken a dump hence the extream voltage at 18+ volts. All the electronics calibrate and referance off of 10-14VDC, If voltage falls out of that range it can throw out what the computer reads. When the alt died on my truck the speedo peged its self way over and this is on a 1990 Jimmy. Get the alternator tested before you dump money and fustration into an ECM.

If you keep drivining it this condition though you will be looking at ahveing to replace the ECM anyways, Park it before you do.

**bigrondownhiller** · 12-04-2007, 01:32 PM

Originally Posted by Orcus79

I wouldn't be so quick to say that the electronics are fried The voltage reg in the Alt could have taken a dump hence the extream voltage at 18+ volts. All the electronics calibrate and referance off of 10-14VDC, If voltage falls out of that range it can throw out what the computer reads. When the alt died on my truck the speedo peged its self way over and this is on a 1990 Jimmy. Get the alternator tested before you dump money and fustration into an ECM.

If you keep drivining it this condition though you will be looking at ahveing to replace the ECM anyways, Park it before you do.

definately have the alternator checked. 18 volts is too much. I wouldnt drive it that much. I had an alternator go bad and put 18 volts. I drove to my friends house to change it. By the time I got there the caps on the battery popped off. I The case on the battery also was pushed out. I had to get a new battery too.

**kool-aide** · 12-04-2007, 01:44 PM

Originally Posted by 0rion

I thought I recognized you. http://www.ls1.com/forums/showthread.php?t=69103

This is why I say NEVER to use a hose on your engine. Cars today aren't like cars 30 years ago. There's a ton more electronics on todays car than in the 70's when you just had to worry about the distributor. Anyhow, don't mean to rub it in but I figured before to long you'd be making this post.

How wet did you get the pcm? It has water tight connectors on it but rubber ages over the course of 8 years. I would start at the fuse boxes and just hit them with a hair dryer and hope you can get whatevers wet dry. My understanding of the instrument cluster leaves a lot to be desired and if someone can enlighten me I'd appreciate it. The cluster gets it's info via serial data cable. What I'm not sure of is how voltage is effected through that cable. That's why I was curious how wet you got the pcm.
Since you mentioned the starter I would definitely put that on the "to check" list. Bad grounds are a pain to trace down. The good news is that it'll mostly likely dry up on it's own at some point in time if it is a water problem. It could just be coincidence that this happened when you washed the engine but I'm betting it's directly related. I see to many of these threads where people have these problems after washing the engine.
Now, watch 2-3 people will post up that they wash their engines all the time with zero problems. 6 months from now they'll be posting up electrical problems after washing the engine bay.

Yep, busted and guilty as charged. Here's the catch, I have been washing, a long with many people I know, my engine for years. Like I said, after every trip to the beach you wash the whole car, top, bottom, engine, everything to get the dirt and salt off. That's just how you're brought up on the coast. That's why I was impressed and so lucky to get a full under body coating on mine. That is rare, but can make a 35 yo car look great.

**kool-aide** · 12-04-2007, 01:53 PM

well, i was never happy with the alt connector. It never wants to stay clamped down right. The wire seems to be about 1/16 too short for some reason. Plus it sits low and would be an easy target for any water off the puddles. I was learning towards the alt, but I have no exp diagnosing a bad one.

What leads me on the alt path is the pulsing, spiking, the high volt output. This all seems to lead towards the alt putting too much on the electrical system. I mean the lights were like ultra bright when on.

I agree this will most likely fry something if i don't find the problem. How much trust do you guys put in the auto store test equipment?

I have an Actron scanner, could it help? I have a scanner and a multimeter.

**bigrondownhiller** · 12-04-2007, 01:55 PM

if you have a multimeter put it on the positive terminal on the alt. if is still reads 18 then the voltage regulator went.

**0rion** · 12-04-2007, 01:58 PM

have you checked voltage across the battery terminals? Start the car and see what the voltage looks like across the terminals. Should be ~14.4 volts. Just watch it for a minute and see if it's spiking.
You know your car better than anyone here so if that alternator is worrying you I'd pull it and have it tested. Go over all those connections with a fine tooth comb and make sure there's no corrosion on the cable ends. I'll even split the insulation back about an inch or so to see if the corrosion runs under the insulator. Just make sure to tape it back up good after you're done.

**kool-aide** · 12-04-2007, 02:04 PM

ok, where exactly on the alt am i reading from? You know that sucker is not easy to get too.

BTW the wires are not in the loom, and look pretty good from a visual. The last time i had a problem was the opp. The loose connection caused a drop in volts and almost killed the car while driving, kind of sucks going down the highway and start to loose stuff.

**0rion** · 12-04-2007, 02:06 PM

check directly across the battery terminals. Set your meter for dc volts and put one on the positive terminal and one on the negative terminal of the battery.

**kool-aide** · 12-04-2007, 02:08 PM

BTW, what are the common causes for an alt to go bad, besides poor quality and old age?

**kool-aide** · 12-04-2007, 02:10 PM

orion, i got that part, not too tough. How about chekcing the alt? would testing across terminals accomplish this? I agree with big round, i would like to test the output of my alt. If that sucker is pumping out too much, then i would agree the regualtor is shot.