Jc803

iTrader: (2)

I've relocated my battery to spare tire well. Now every time I start my TA some things are acting strange. First thing I notice is the odometer trip resets every time. Only on start though. If I drive it I can turn the car off, the turn the power on and the miles stay, but they reset when I start the motor. That made me think the fuel trims are probably resetting too so I checked with my LM2 and I am correct, they are resetting as if I have disconnected the battery. The third thing I've noticed is when I start the engine, the mph, tach, water temp, and fuel needles stay bottomed out for a few seconds, then raise almost all the way up, go back down, then after a few seconds return to where they normally should be.

Anyone know what could cause this? I dont think its the wiring. I have the battery negative bolted to frame rail, the power cable is run to a 200 amp fuse, then up to the front to a distribution block where the three other power cables are run to. The old negative ground cable is also bolted to the frame rail. Could I have blown a fuse or relay? Or maybe the battery just doesnt have enough cranking amps? It starts just fine and battery is 2 months old but I dont know.

Here is a pic of the block I'm using



Here is a video of what the gauge needles are doing

RockinWs6

Voltage is dropping too low or out.

jimmyblue

iTrader: (11)

I think your frame rail connection is too crappy to
handle a hundred amps of starter current. If I were
you I'd add a fat welding cable for the ground and
return it to the block and the front sheet metal as
in the stocker.

Ground rise is the same, in effect, as voltage drop.

Jc803

iTrader: (2)

I forgot to mention, the power and ground wire is 1 gauge, 4704 strand speaker wire. wouldnt that be better than welding cable? When I was researching this I saw a lot of people saying that wire with a lot of strands would be better than welding cable

FAD2BLK93

I recently had guage problems myself. Try just adding a simple ground inside the wheel well or sheetmetal nearby. Then turn the car on and go from there. Rule a ground connection out first. Mine had a bad ground (intermintent), my guages would all go halfway up then down...many other weird things happened. I dont fully trust aluminum as a ground. Not the first motor...heads...that were aluminum that i have had ground issues with. Rule it out first, then chase something else. Just my .02 good luck

jimmyblue

iTrader: (11)

There is a kind of goop that you can get at electrical
supply places to prevent aluminum - copper junctions
from getting all crusty over time.

I'd use #0 or #00 welding wire for that long of a run.

You might have somebody repeatedly crank the motor
while you measure B+ - B- voltages along the wire-pair
from battery up to the starter and the point where the
PCM picks up its ground feed. That ought to reveal
something.

Jc803

iTrader: (2)

Ok thanks guys. Will do

Paul Bell

iTrader: (9)

The "goop" is called anit-ox, it can be bought at any electrical supply house-and probably in the 'lectrical isle of Home Depot.

Current doesn't care if the wire is highly stranded or not-so long as the gauge size is good for the amperage drawn.

For the gauges jumping, you need to pull the cluster and send it to Model Electronics. They'll swap a faulty chip and your problem will disappear.

http://www.modelelectronics.com/index.asp

Jc803

iTrader: (2)

I dont understand why it would be a faulty chip. Everything was working fine two days ago before I relocated battery. Also that wouldnt explain the fuel trims reseting. They're only supposed to reset when the battery is disconnected.

Paul Bell

iTrader: (9)

Many of these cars had this faulty chip. Sometimes it doesn't show up until some electrical work is done or the grounds have changed. Cold weather can trigger it too. Back in the day, GM had a service bulletin on it to make the repair.

You won't fix it by reinforcing the battery cables.

Jc803

iTrader: (2)

Well I'm starting to believe you Paul Bell. I added two more 1 gauge grounds to battery negative for a total of 3, 1 gauges. I also added a 1 gauge from block to chassis along with the factory ground from block to chassis.

I still only have the factory power wire running from the distribution block to the starter, so next thing I'm going to do is probably run a 2 gauge from distribution block to starter. If that doesnt work then its got to be that chip like Paul Bell said

RockinWs6

Measure the voltage at the computer when you start.

Paul Bell

iTrader: (9)

Some people cured this problem by replacing the battery. However, it's still a sign that the instrument cluster needs the chip upgrade. A "good" cluster will not reset during occasional reduced voltage.

Jc803

iTrader: (2)

Where would I measure the voltage at computer and how many volts am I looking for

I've crossed the battery off list of possibilities. Date sticker says it was made in July of this year. Also has 750 cold cranking amps. So if replacing the stock starter wire with a 2 gauge doesnt work then I guess the only possible thing would be the chip in cluster

Jc803

iTrader: (2)

Unless RockinWs6 is on to something. Not enough power to computer would make everything reset like that. I noticed every time I put the cables back on the battery the cluster does that thing with the needles which I'm sure is normal. Maybe everytime I start the car the computer isnt getting enough juice and resets. Guess while I'm at it I'll just go ahead and replace all the wires

Paul Bell

iTrader: (9)

The gauge set is it's own entity-the PCM does not operate it. It receives information from the PCM and translates it into the display gauges.

Low voltage at the PCM will not cause malfunctions in the gauge cluster.

The PCM is designed to operate from like 9 volts to 18 volts.

Jc803

iTrader: (2)

Well it has to be that chip. I've run all new thicker wire to everything and more than enough grounds. That did fix the problem with the fuel trims reseting every time on start up. But the cluster still does the same weird things. I'm not worried about that too much though. I really just wanted the fuel trims to stop resetting. But I guess a lot of us learned something new thanks to Paul Bell

PwrdbyLS1

iTrader: (5)

Hi JC803, did you finally fix your gauges problem? I have the same problem with mine. Everytime I start the car, the gauges flip and my color from my pillar pods gages also reset just like if I unplug the battery.

GoodSpeed150

iTrader: (7)

Any updates?

G Atsma

On a 5-year old thread? Don't hold your breath...