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 > Dashboard Amp gauge reading high.

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Ontario, Canada

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Posted: 02/12/18 04:36pm Link  |  Quote  |  Print  |  Notify Moderator

In my camper van my amp gauge has started to read higher than normal.Where it used to read at the half way point it is now reading between 1/2 and 3/4. Thinking it was a bad voltage regulator in the alternator I decided to change the alternator. No good, it still reads too high. I do have a battery isolator under the hood but don't know if that has anything to do with it. Leaving for Florida next week and don't want this to turn into a major problem. The starting battery seem fine in cold starting , not sure about house batteries. HELP

1990 L.E.R. Dodge B 250 Class B 17'


Horry County

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Posted: 02/12/18 04:46pm Link  |  Quote  |  Print  |  Notify Moderator

The start battery may be ok... And we know its not the alternator... Maybe the house battery on its way out.

Only when the car is running does it try to charge the house battery...

Check the voltage of the house battery in the morning after car sat for awhile. Or do a hydrometer test of the cells.

An easy way would be disconnect the house battery and see if the issue goes away..

Mike L ... N.J.

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Itchey Feet


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Posted: 02/12/18 05:05pm Link  |  Quote  |  Print  |  Notify Moderator

Check with a multi-meter @ the alternator, could be just a gauge going bad. JMHO

My feet are fine as long as they are traveling.


Ontario, Canada

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Posted: 02/12/18 05:35pm Link  |  Quote  |  Print  |  Notify Moderator

I did disconnect the cable from the isolator to the house batteries but there was no change.




Joined: 06/27/2004

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Posted: 02/12/18 05:53pm Link  |  Quote  |  Print  |  Notify Moderator

Borrow or buy
A clamp on DC amp meter
Check the amps going to the engine battery and the house battery

Voltage checks tell you nothing, unless the voltage is to high
And is over charging the batteries
You have a bad battery
Unless the dash guage are going wonky
Or the starter circuits are going out and have developed a sticky contact, which will eventually burn something out

Radiate The Happy

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Moses Lake, WA

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Posted: 02/12/18 06:47pm Link  |  Quote  |  Print  |  Notify Moderator

Amp gauge? I think it is more apt to be a voltmeter.
I would use a volt meter on the alternator side of the isolator, and then check each of the outputs.
What kind of reading is the dash gauge showing?

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Bothell Wa.

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Posted: 02/12/18 07:08pm Link  |  Quote  |  Print  |  Notify Moderator

Some Chrysler/Dodge vehicles from a bit earlier than the OP's rig did have ammeters.
Have you added anything lately? It's possible to add a load down stream of the gauge and have the meter show a higher reading than it really should. I have a vintage car that did this after adding a rad. cooling fan. Doesn't hurt anything.

Scott, Grace and Wesly
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Posted: 02/12/18 08:07pm Link  |  Quote  |  Print  |  Notify Moderator

Dashboard ammeters are notoriously inaccurate.

First, clean the battery terminals and the top of the battery. At a minimum, spray it down with a strong spray from a garden hose. Max sure the battery terminal on secure.

Get a digital multi-meter. The $6 Harbor Freight meters are not very good, but their $24 meter is not bad. Craftsman has a few to choose from in the $35-$50 range. No need to spend more than that.
  • Check and record the battery voltage before starting.
    It should be between 12.0 and 13.0
  • Turn the key on, high beams on and heater blower on high for about 5 minutes.
    Check and record the voltage. It should be above 11.0
  • Start the engine. Check and record the voltage. At a high idle, it should be above 13.8 but below 15.0
  • Go for a 10-15 minute drive with all accessories turned off. Check and record the voltage at idle. It should be between 13.2 and 13.8

The last reading is the one that would indicate over charging. But over charging could be caused by a high load.


Southern California

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Posted: 02/12/18 08:10pm Link  |  Quote  |  Print  |  Notify Moderator

Ignore it and go.

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Near a large body of salty water

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Posted: 02/12/18 08:31pm Link  |  Quote  |  Print  |  Notify Moderator

I have the same vehicle as the OP but one year earlier. The engine computers are interchangeable.

The voltage regulator is inside the engine computer, not the alternator.

Does your alternator look like this?
But double V belt pulley.

The dashboard Ammeter on mine, the needle did not move enough to alert me to alternator failure in 2004. A simple voltmeter would have. These Ammeters are not the same mopar ammeters of yesteryear, which funnelled a lot of current through he firewall.

The only times I saw the stock ammeter gauge raise a significant degree on mine, was when the engine battery itself was well depleted in addition to the house battery, and this happened only as long as the engine computer chose to seek 14.7 or 14.9v right after startup.

Usually the engine computer would seek to attain/ hold 14.9v for a few minutes then was 13.7v max with the occcassional blast back upto 14.9v for no discernable reason.

A tachometer now resides where the stock Ammeter did.

I will Theorize that perhaps your engine battery is not isolated from house loads due to 'isolator' failure.

BUt I would just throw my DC clampmeter over a cable first and see if high amps are indeed flowing into engine battery. Then the same for house battery.

Usually if the VR in the engine computer fails, then there is no charging occurring. Voltages with engine running will be below 12.8 and keep falling.

What is your voltage when your ammeter reads sky high?

Are the fuel gauge and temperature gauges also reading high?

Have you cleaned the engine battery post clamp surfaces, and the battery to firewall ground( behind battery) and the battery to engine ground?

Any other weird electrical occurrences?

Have you pulled the computer codes via the 'key dance'

There are ways around having the engine computer regulate the voltage with this vehicle. I spin a pot on my dash and watch voltage at battery terminals, and amp flow into the battery, respond accordingly.
It gives me joy. It is enlightening.

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