My Amp Gauge is Amping

[Driftwood]

The last two days my amp gauge needle has been pinging into the + range. It seems to have a steady beat. The needle will bounce up into the + range about half scale. Tonight I was driving all the other motorists nuts because the headlights would flare and glare in unison with the pinging amp gauge needle. Do I have a bad ground? Is the voltage regulator going bad? Will my 84 GW catch on fire? The amp needle goes crazy when I roll up the windows. :mad: :confused: :(

[Bob Barry]

Figure on your dash catching fire soon. The ammeter is probably failing, causing the big red wire from the alternator to it to overheat, melt through the insulation, and short to ground. This will melt your dash harness, igniting anything flammable under there.

You can bypass your ammeter a number of ways (check the archives for the how-to) to prevent this. Check to see what damage may have already been done to your wiring.

[2man]

Is there an easy way to remove the gauge cluster? I know you remove the screws but I have h*** trying to get the cluster out. Do I pull from a certain side? Is there something else holding it in? I tried to get it out before and gave up. I paid a mechanic to do it for me (I've screwed up enough things to know when to quit). Now I've got enough things under my belt to try again. Not to mention Bob scaring the you-know-what out of me. Seriously, thanks for your help Bob.
smile.gif

[Dive 30]

My guess would be your voltage regulator on your Alt. You can have your batt/altenator checked for free at Autozone/Checker/Parts America. If not, then I would agree with Bob and start digging under the dash.

You can bypass your amp meter very easily. You should have a 10gauge wire (mine is yellow, but mine is a year newer) that runs from your batt. to the firewall. Continues from firewall up to amp gauge. Out of amp gauge is Red (again, color may vary). To see this you will have to drop driver's side AC duct (there is a resistor and a cabin light attached to it plus your 4WD selector so be careful). You should be able to examine the wires for signs of heat stress (wire very stiff/discolored/deformed insulation). You will have to make the call on how far to remove the old wiring and replace with new. My Philosophy: When in doubt, replace it! Electrical probs are not fun.

I hope that helps.
Phil

edit: if you have a meter, while the vehicle is running, you can check for voltage at the alt. or batt. If it is spiking 14+ that might help you determine if it is the voltage regulator. Have you noticed any probs with the battery? Sometimes over volting the battery will cause a strong sulpher smell.

[ October 06, 2001: Message edited by: Dive 30 ]

[Mud Thrasher]

Taking the panel out can be tricky. Just be persistant. First reach up in there and take the speedo cable loose. After you get the screws out slowly pull the right side out. It helps if you put the tranny in 1 or 2. You sorta have to pull the top out to get it to go. Once you get the right side away from the dash slide it to the right so you can get to the heater vacuum hoses. Unhook them noting where they go and just work it out. Then you can get to the wires on the back of the panel.

[la mula pescadora]

i got this same problem on mine runing high amperage can sure melt the wires and cause a big fire under ur dash i won't recomend for u to drive it like that what u can do to drive it will be desconecting ur filds wires on the alternator this will cause a no charge on it but at least u can drive it safe.
and most likely it is going to be the voltage regulator or alternator u can have them both check at ur nearest part store and make sure u check all the wiring for melt down before u drive it

[2man]

Here's an addition to the problem that I overlooked. When the meter is going crazy, I can turn on the A/C and the meter will behave. Or, if it doesnt, I can turn on enough electrical stuff and it will behave. While the A/C is blowing hard I've noticed that when the gauge starts this crap, the blower motor will barely blow. Then, all of a sudden the blower motor will come back up to normal and the meter will act right. Hope this helps to make a diagnosis. :confused: :confused:

[Dive 30]

I still say Altenator. Especially if it corrects when put under load.

Besides, it's about time you got that 140 amp altenator and those dual Optimas you've been talking about! :D :D :D

[Snakeyes_Tx]

Well, is it normal for the ammeter to be that sensitive to twitch a little? My lights dim at idle in Drive, but when I tap the gas just a hair, it's okay again and the ammeter needle stops bobbing its half a micron jig.

I think we just have weak alternators not being able to handle the load of all our power goodies.

[Dive 30]

See, I had the same problem even after I put in my 140 amp altenator. But, when I ran a #2 ga. wire from the alt. to my battery, it fixed it. At least on mine, the alt. had to handle the load of everything on a ten ga. wire. Of course, means that my amp gauge doesn't work anymore because the current doesn't flow through any more. But, it's much better performance wise.

[Driftwood]

I spent all day yesterday working on my 84 GW with the pinging amp and flashing headlight syndrome. I would think that since I am a Avionics Tech in the USCG and have been working on helicopters since 91 that I would have had this problem wrapped up in an hour or so. But it is difficult to work on a electrical system when you don't have a real schematic to read.
The problem is still there but this is what I found during the troubleshooting. The following wires were charred and melted together. 10 amp yellow wire from the starter solenoid, oil pressure wire, 10 amp red wire from the back of the alternator, black wire (1 of 3 wires) going into the distributor cap, Water temp wire, red wire for carb bowl vent solenoid, carb solenoid wire. I don't think I forgot to mention any others. I completed the numerous repairs with brand new wire and splices and finished around ten last night. I also installed new 4 gauge battery cables. The ones I removed looked like 6 gauge. I still need to replace the cable from the starter solenoid to the starter.
I dropped the instrument cluster and everything looked fine. No charred, cracked, or frayed wiring at the amp meter or anywhere else. I'll be at it again today.
(to be continued)

[ October 07, 2001: Message edited by: Driftwood ]

[Dive 30]

Drift, do you think the wires were charred and melted due to dropping down on to the exhaust manifold or other heat source(very common) or due to an electrical problem that caused them to heat excessively?

[Driftwood]

Thats exactly what happened with those wires. The whole bundle was resting near the exhaust manifold. That black plastic wire wrap was completely melted or missing from the heat. I'm in the process of re-wrapping the wire bundle with new black wrap that I picked up from Auto-Zone.

[Joker's '88 GW]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Driftwood:
Thats exactly what happened with those wires. The whole bundle was resting near the exhaust manifold. That black plastic wire wrap was completely melted or missing from the heat. I'm in the process of re-wrapping the wire bundle with new black wrap that I picked up from Auto-Zone.<HR></BLOCKQUOTE>

Drift: I feel your pain! I'm fighting the same situation on my '88. The wire bundle dropped onto the exhaust manifold and melted everything into a ball!

I have finally (I hope) gotten all the wires replaced with correct gauge splices and am working on rerouting the wiring away from the engine/exhaust. I have the wire wrap and will try and reroute them using that.

I'm also running a high-output alternator so will be changing the battery cables to a bit thicker. I have them, just need to do it.

Good luck with the repairs..

[la mula pescadora]

i might do the same as Dive 30 remove the red wire that goes to the amp meter (replace it with a voltage) rutn the chargin wire direcly to battery then splice the power cable that runs from selenoid and put a fuse on it just to be safe how thoes this sounds?

[Teach]

Without going into too much depth, what is the biggest/highest amp stock alternator that can be put into my waggie?

[Snakeyes_Tx]

Premier Power Welder's 600 Amp Alternator :D

[Driftwood]

Ok. I think I have repaired all the burned or chaffed wires under the hood. After those repairs I decided to solve why my backup 25 amp fuse kept blowing. I removed the fuse panel from the fire wall and removed the red wire from the fuse panel that is downstream of the fuse. I carefully removed the wire bundle black wrapping from the wire bundle and followed the wire till it reached a soldered 5 way splice. Red wire #1 routed back to the firewall connector and provided 12vdc to the tranny back up switch (and backup lights I suppose), electric choke, carb bowl vent, and carb idle solenoid. Red Wire #2 went to the blue chime module in the fuse holder. Red wire #3 went to the cigarette lighter, and Red wire #4 went to a "mysterious" relay. I later discovered through tracing those wires from the relay that they somehow controlled the seatbelt dummy light and was wired in to the chime module next to Red wire #2. With a volt meter I was able to determine that the "mysterious" relay was internally shorted through the relays ground wire, allowing voltage directly to ground thus blowing my 25 amp fuse. I removed the "mysterious" relay. Now I can enjoy having my backup lights illuminating, and a operable electric choke. And my cigarette lighter works! I fired up the waggy after reinstalling the fuse panel and firewall connector. Hooked up the amp meter wires and turned on the headlights. NO MORE PINGING AMP METER AND FLARING, GLARING HEADLIGHTS! WOO HOO! :D WHO'S THE MAN!

[ October 08, 2001: Message edited by: Driftwood ]

[Driftwood]

There may be another problem that has suddenly appeared that wasn't there before. If I can't fix it I will seek online help. :confused:

[Driftwood]

Problem solved! The resistor wire that is attached to the alternator via a small plastic connector had some melt damage to it's insulation. I removed about two feet of it. With the jeep running, I would turn the engine off, but it would remain running. I reinstalled the damaged resistor wire (which measured 35 ohms) and the problem disappeared. Isn't that about the strangest thing?

[Bob Barry]

Not really; trucks with MSD ignitions have that problem all the time. The trace of power that backflows through that wire is enough to power the truck, even when the ignition switch cuts the main flow of power.

On most vehicles, the "GEN" light provides sufficient resistance to cut down that electrical flow and make it insufficient to power the ignition system. On trucks with gauges rather than idiot-lights, the resistor wire serves the same purpose (or so I've been led to believe).

[Driftwood]

AAAARRRRRRRRGGGGGHHHHHH
My Flaring, glaring headlight, pinging amp meter situation as re-appeared. I tried several different thngs to determine what is wrong. With a volt meter, I am showing 13.5 volts at the battery with the lights on (flaring of course) and engine running. With the negative cable removed I get a voltage reading of 14 volts, a smoother running engine, and no flaring, glaring headlights, tail lights, instrument lights, courtesy and dome lights. I checked the battery fluid. It is low but the fins are not exposed. Can a battery be causing this problem? Or a faulty alternator? I rebuilt the alternator 2 years ago by replacing the diode board and brushes.

[Snakeyes_Tx]

What's your idle at? I set my PARK Idle at around 1050 or so, that seems to curb the flickering a little.

[Driftwood]

Snake Eyes, I haven't checked my idle setting, but this problem occurs at idle and during driving conditions. I'll be taking it in to NAPA today to check the battery and alternator.
Bob Barry, Thanks for the info about MSD ignitions. It really makes sense. As soon as I spliced that resistor wire back in, the engine no longer kept running after the ignition was secured.

[Bob Barry]

I'd suggest you take your ammeter out of the charging circuit and see if that improves matters at all. It's quick and free.
Disconnect the battery, remove the left A/C ductwork, and with a 3/8" wrench, reach up and unbolt the nuts holding the 10ga wires to the studs on the back of the ammeter. Clean off any corrosion, place both ring terminals on the same stud, and tighten them down.

If your ammeter is anything like mine, it can fail by causing extra internal resistance, which causes the alternator to try and charge past the resistance.

This causes a few things, that you have seen: The lights and other accessories (on the charging side of that circuit) see all that extra voltage, causing the flareup you describe, and the extra resistance causes a lot of HEAT, melting the ammeter and the wiring leading up to it.

While this theoretically should burn out the fusible link coming off the charging post on the alternator back to the "big splice" under the dash, it sometimes doesn't, and sometimes the fusible link has been "deleted" by a DSPO, so that big red wire through the big red splice turns into a fusible link with a much higher rating...

[Driftwood]

Bob, I gave your tip a try a few days ago but I still encountered the same problem. I had several shade tree mechs tell me today that they think the voltage regulator within the alternator is going bad.

[Teach]

Funny Snake...I meant real world, can afford it type of alt.

[Bob Barry]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Dive 30:
See, I had the same problem even after I put in my 140 amp altenator. But, when I ran a #2 ga. wire from the alt. to my battery, it fixed it. At least on mine, the alt. had to handle the load of everything on a ten ga. wire. Of course, means that my amp gauge doesn't work anymore because the current doesn't flow through any more. But, it's much better performance wise.<HR></BLOCKQUOTE>

I did the same exact alternator bypass, but with a 10ga wire from the alternator to the full-time (+) stud on the starter relay, and using a 14ga fusible link to save it in case of a short. If my ammeter ever does start working, I know I've got a problem. What I'd really like is a voltmeter from some factory application that would plug into place of the ammeter.

But, Driftwood, if the problem isn't the ammeter itself, I bet it's the voltage regulator being damaged by the previous wires burning out. You can either replace the regulator inside the alternator itself, or get a whole new one if the old one is still under warranty.

[Driftwood]

I HAVE SUCCEEDED! My amp gauge, lighting, and all other electrical systems onboard my 84gw has been repaired. It turned out to be the voltage regulator in the alternator. I replaced the alternator instead of repairing it. It couldn't have been a simpler fix, but at least I was able to replace some damaged wiring under the hood that had a encounter with the exhaust manifold. I found what was causing the BU/SEATBELT 25 amp fuse to keep blowing. It turned out to be a shorted relay controlling the seatbelt dummy light and chime module. The relay is located behind the instrument panel. The Carb bowl vent, High idle solenoid, electric choke, cigarette lighter, back up lights, chime and seatbelt light all receive power from the BU/SEATBELT 25 amp fuse. I know because I physically traced all the wires by hand. While I was at it I installed a new rebuilt steering box from NAPA (I love them, They love me!). The old one was draining fluid faster than I could pour it in to the pump. Next task will be to get the leaking transmission rebuilt or replaced. smile.gif

[ October 11, 2001: Message edited by: Driftwood ]

[Bob Barry]

DW,

Darn, you fixed it.

Now what are we going to talk about...?

;)