Jump to content

97 Tracker 5V Ref Current Capability Question

Recommended Posts

My ECM's 5V reference falls to 1.5V with the fuel level sender plugged in. (Just replaced - old one was open.) I get an Ohms reading of 70 Ohms at the ECM connector (disconnected from ECM) with all circuits connected. That means I'm only drawing about 75 mA from the reference but it falls to 1.5 VDC. I haven't taken an Ohms reading with the fuel level sender disconnected since the reference comes back to 5VDC with it disconnected. (70 Ohms seems reasonable with less than half a tank of gas- the sender is 40 Ohms at empty.)
If no one knows can someone with a 96-98 Tracker, disconnect the center connector (there are three) from the ECM and take an Ohms reading from your reference circuit (gray/red wire) to ground (I used the steel dash plate - under the steering wheel, directly behind the plastic panel). Please include the fuel gage reading at the time for your vehicle (it makes a big difference, 270 vrs. 40 ohms).
THANX . . . Hoping it's NOT the ECM . . . but it looks bad.

Link to comment
Share on other sites

  • Administrators

TrackerJack...Perhaps a Tracker owner/member or guest might help with the test you need... 

I suggest a non-destructive insulation resistance test followed by isolating harnesses and checking resistance.  Tests run with a Fluke 1587 or equivalent meter can find insulation leaks to ground or between wires that might never show up with a simpler continuity or Ohms resistance check.  For an automotive system, I'd start with a lower voltage setting like 50V range.  (These tests are often run at much higher voltages with these meters yet cause no trouble.  The amperage is very low.)  Disconnect the battery, this is strictly a wire and connector test. 

Even though a Fluke 1587 or equivalent insulation resistance test is non-destructive and low amperage, I would still disconnect the ECM before and during these tests.  The board's circuitry or any sensitive diodes may not response well to these voltage tests.  For harnesses and connectors, the meter's non-destructive voltage test could prove useful.

Keep in mind that this is DC voltage.  Grounds and grounds resistance are as important as the hot or positive leads...Watch for grounding point resistance. 

Let us know how this turns out...


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...