Jeep Enthusiast Forums banner

Quick Gauge test

10928 62
Temporarily opened for suggestions..

For a video, go here: https://www.jeepforum.com/forum/f8/quick-gauge-test-4390781/#post40900235

CJ Speedometer Gauge Quick Test

By: John Strenk

------------------------------------------------------------------------------------

OK, You know what your doing. You don't need a long explanation. Just a test light. Maybe a DVM.

Automotive lighting Asphalt Automotive tire Eyewear Automotive exterior
Yellow Measuring instrument Clock Gadget Electronic device


************************************************************

One Warning. A poor broken ground connection or hooking up the plugs incorrectly can quickly burn up the gauges or sensors. Don't make matters worse. Double check your connections before turning your ignition key to 'ON'
Add a ground wire from the dash to the (-) negative terminal of the battery to be sure.


************************************************************
Step 1. Start Here


Turn key to ON. Attach your test light clip lead to a good ground.

You may want to disconnect your Ignition coil. These have been known to burn up if the key is 'ON' but the engine is not running.
41 - 60 of 63 Posts

·
Registered
Joined
·
16 Posts
My thanks also!

My problem is with the voltmeter (1986 CJ7 factory guage). Needle doesn’t move—I put known 12 bolts across it and it still doesn’t, so I know the guage is bad.

What I can’t figure out is, with my multimeter red pin on the yellow wire and the black pin on a good ground, it reads bogus number-like 150. That’s with the key on. With the multimeter across the battery it reads about 13 not running, and in the 14’s running.

Shouldn’t it read the same under the dash, minus a small drop?
 

·
Super Moderator
Joined
·
24,203 Posts
Discussion Starter · #57 ·
150 volts? Sure it’s not reading millivolts? Look for a little “mV” on the meter some place.


Yes, it should read the same subtracting a little for the voltage drop for the distance it has to travel.

Have you verified the ground connection? Such a millivolt reading could easily happen with a poor ground.
 

·
Registered
Joined
·
16 Posts
I have not checked the oil pressure hot wire-I'll check that.

I did pull the connector to/from the ignition switch (on top of the column). There should be continuity from the heavy guage yellow wire (that goes from the ignition switch to the fusebox) to the yellow wire at the voltmeter. There is not.

According to the diagram, they connect in the harness between the ignition switch and the fusebox. The harness is unmolested, so I didn't imagine any corruption of the connection of those two wires. before I unwrap that area to check, Ill make a last-ditch effort to check the terminal at the meter end to see if contact is broken there.
 
41 - 60 of 63 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top