2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Testing Gauges for functionality.

Thread Tools
 
Search this Thread
 
Old 02-03-11, 10:10 PM
  #1  
A Never Ending Project
Thread Starter
iTrader: (2)
 
JK5S's Avatar
 
Join Date: Jan 2011
Location: Salt Lake City
Posts: 205
Likes: 0
Received 0 Likes on 0 Posts
Testing Gauges for functionality.

I removed my entire gage luster hoping to test the fuel and volt gauge. I've tried using a 9 volt battery on the pins but no luck. does anybody have a suggestion as to how to test these directly?
Old 02-04-11, 12:20 AM
  #2  
whats going on?

iTrader: (1)
 
SirCygnus's Avatar
 
Join Date: Mar 2004
Location: atlanta ga
Posts: 4,929
Received 8 Likes on 7 Posts
i believe the fuel level sensor is just a resistor.
Old 02-04-11, 06:43 AM
  #3  
Rotary Freak
 
HAILERS2's Avatar
 
Join Date: Jul 2008
Location: FORT WORTH TEXAS
Posts: 1,660
Likes: 0
Received 1 Like on 1 Post
The FSM has procedures for testing the gauges. I think the section is BODY ELECTRICAL.

Just what is wrong with the gauges right now?

For the gauge they just install a resistor of a fixed value in a given pin at the fuel pump connector and read the gauge. They use a Mazda tester but you don't need that. Just look at the picture they give which shows what the gauge should read using different resistors.

All they do with the voltmeter is put a meter on the batt posts and start the engine. They compare the gauge in the car with the meter on the batt posts. They recommend r square the sucker if it does not agree with the meter reading on the batt posts. A little radical imho.
Attached Thumbnails Testing Gauges for functionality.-meter.jpg  
Old 02-04-11, 08:19 AM
  #4  
A Never Ending Project
Thread Starter
iTrader: (2)
 
JK5S's Avatar
 
Join Date: Jan 2011
Location: Salt Lake City
Posts: 205
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by HAILERS2
The FSM has procedures for testing the gauges. I think the section is BODY ELECTRICAL.

Just what is wrong with the gauges right now?

For the gauge they just install a resistor of a fixed value in a given pin at the fuel pump connector and read the gauge. They use a Mazda tester but you don't need that. Just look at the picture they give which shows what the gauge should read using different resistors.

All they do with the voltmeter is put a meter on the batt posts and start the engine. They compare the gauge in the car with the meter on the batt posts. They recommend r square the sucker if it does not agree with the meter reading on the batt posts. A little radical imho.
I belie the gauge itself is at fault cause it is not moving at all if I ground the fuel level sensor. I've seen that page from the FSM but I would like to test the movement of the gauge.
Old 02-04-11, 10:09 AM
  #5  
Rotary Freak
 
HAILERS2's Avatar
 
Join Date: Jul 2008
Location: FORT WORTH TEXAS
Posts: 1,660
Likes: 0
Received 1 Like on 1 Post
Well I don't have a spare cluster to work on, but it seems that if you look at the jpg attached you could put batt voltage on what is referred to as A2 and put the ground to A1 and the meter should read whatever the batt voltage is. I'd use the car battery as the power source.

Some threads on this site mention the screws on the back of the meter/cluster as being the problem. If memory serves the screws are what make contact b/t the meter and the circuit board traces.

Seems fuel would be A2 for pos and B3 for the gnd for the fuel. Sort of a momentary touch of the neg to see if the gauge needle will move at all. I wouldn't want to peg the needle.

That's for a series four car. Series five might differ. The wire colors should match what is shown on the second jpg. Like A2 is black/yellow or B/Y to get you started. Powers all the gauges I believe. A1 should be black but on early 86-86 might be brown/black.
Attached Thumbnails Testing Gauges for functionality.-gauge.jpg   Testing Gauges for functionality.-metertwo.jpg  
Old 02-04-11, 12:18 PM
  #6  
A Never Ending Project
Thread Starter
iTrader: (2)
 
JK5S's Avatar
 
Join Date: Jan 2011
Location: Salt Lake City
Posts: 205
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by HAILERS2
Well I don't have a spare cluster to work on, but it seems that if you look at the jpg attached you could put batt voltage on what is referred to as A2 and put the ground to A1 and the meter should read whatever the batt voltage is. I'd use the car battery as the power source.

Some threads on this site mention the screws on the back of the meter/cluster as being the problem. If memory serves the screws are what make contact b/t the meter and the circuit board traces.

Seems fuel would be A2 for pos and B3 for the gnd for the fuel. Sort of a momentary touch of the neg to see if the gauge needle will move at all. I wouldn't want to peg the needle.

That's for a series four car. Series five might differ. The wire colors should match what is shown on the second jpg. Like A2 is black/yellow or B/Y to get you started. Powers all the gauges I believe. A1 should be black but on early 86-86 might be brown/black.
I appreciate the help.
I did tare the cluster apart and noticed exactly what you were saying above, the screws holding the gages while at the same time providing connection had rusted heads. I wonder if moisture is to blame. When I get home I will try using the car battery for testing, so far I've been using a 9 volt battery and I tried a 12 V power adapter without any luck.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rgordon1979
3rd Generation Specific (1993-2002)
40
03-15-22 12:04 PM
ZacMan
Build Threads
4
09-19-15 09:20 PM
gabescanlon
3rd Generation Specific (1993-2002)
7
09-05-15 12:09 AM
gabescanlon
3rd Generation Specific (1993-2002)
4
09-05-15 12:04 AM



Quick Reply: Testing Gauges for functionality.



All times are GMT -5. The time now is 07:40 AM.