Gauges stopped working! PLEASE please please help... I'll give you a cookie

[gixxer750]

Well, when I took my dash out, and put it back in, some of my gauges don't work anymore. My tach is one of them, also oil pressure gauges, and water temp. Check engine light does never comes on. I've tried three different clusters, checked grounds, added external grounds, and checked all the fuses.


Seems that they have power and ground, but not signal. My voltmeter works(so did the boost gauge) clock works, door ajar light works, and the backlighting works. So do tems lights and the brake light.

I am lost, and have been stuck on this for a couple of days. It's keeping me from driving my car

 

[gixxer750]

not even any ideas?

 

[plaaya69]

I would recheck the 7.5A gauge fuse and the 7.5A ing fuse also(even if they look good). I had the same problem in my supra it seemed like only half of the cluster was working but it turned out that I just had a bad 7.5A gauge fuse.

 

[CRE]

Well, if you pulled the entire dash I presume you pulled the ECU and disconnected a few junctions as well. Have you checked them out for signs of corrosion on the pins and receptacles?

I know it's not much, but I'm drawing a blank on this one. If you hadn't already tried three different guage clusters I'd suggest the flexible circuit on the back of the cluster.

 

[gixxer750]

I replaced both fuses. I have voltage there. I have grounds to the cluster.

I tried multiple things. I took another cluster with no sheild over it, moved the temp hand all the way to hot. When I turned the key on it went straight to cold immediatly. The gauges have power, but no signal.

 

[plaaya69]

Also your 15A efi fuse under the hood is good also correct?

 

[CRE]

Does the car run? You might also take a look at the fusible link under the hood... I've seen alot of those corroded to the point where they'd pass just enough current for somethings but not others. If the car runs, forget I mentioned it.

Testing for voltage is a start, but it won't tell you for sure that there's not a hairline break in a line. Test with a load (resistor between positive and ground) on the line. If there's a fine break in a line it'll sometimes pass enough current for you to get a voltage reading, but still won't provide enough when under a load. Another way you could check is testing the resistance across each suspect line.

 

[jdub]

Take a look at this diagram:
http://www.cygnusx1.net/supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=136

It shows gauge fuse power flows through connector 1F on Junction Box (J/B) #1 in the left kick panel
http://www.cygnusx1.net/supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=16

Then to connector E3 (again left kick panel):
http://www.cygnusx1.net/supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=28

To J/B #3, connector 3B (left kick panel):
http://www.cygnusx1.net/supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=20

To connector C (the blue one) on the back of the cluster:
http://www.cygnusx1.net/supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=139

You should have 12V, ignition on at terminal 8 on the blue connector (yellow wire, connector C):
http://www.cygnusx1.net/supra/Library/TEWD/MK3/manual.aspx?Section=Main&Page=138

Work back from there and check all the connectors...one may be disconnected. Ground is at the J/B #1 set bolt and flows the reverse of the above; white and black wire.

Couple of questions:
Did you replace or remove the stock boost gauge?
Does your rear defogger work?

 

[gixxer750]

I replaced my boost gauge with a voltmeter, but after all this happened. The car cranks, runs, idles and everything else. With the car running, tach does nothing.

I dunno about the rear defogger. I'll have to check that out.

 

[gixxer750]

where is jb 1 set bolt?

 

[jdub]

I'm pretty sure the boost gauge drive circuit box is required to complete the circuit, even if the gauge itself is removed. You can get around this by making a jumper wire and connect it between the 2 screws (pens are pointing to in pic). This will be required to get the voltmeter to work regardless and provides a ground for the voltmeter. After you jump it, you can remove the boost drive circuit box. Give this a try 1st...I'm thinking your cluster is not grounded.

Check for 12v at the blue connector per above as well.

The tach will not work unless the gauge cluster is getting power.

The J/B #1 set bolt is the one attaching the J/B to the chassis

 

[cjsupra90]

When you say that you pulled the dash out, do you mean the entire dash or just the cluster?

If you mean the entire dash, then my bet is that the M1 (engine harness to dash harness) connector is not connected. That connector has all the signals that you seem to have lost.

 

[BJ91T]

When you say that you pulled the dash out, do you mean the entire dash or just the cluster?

If you mean the entire dash, then my bet is that the M1 (engine harness to dash harness) connector is not connected. That connector has all the signals that you seem to have lost.

what does that connector look like??? how many pins etc?? gixx this could be that one yellow plug that we dont have plugged in if not then i am also at a loss after trying to figure this out for the past 2 days over the phone

 

[gixxer750]

I already did the ground jumper on the volt meter. I figured that one out when I did that swap by looking at the na cluster. I seem to have a ground, because the cluster works. I took some wire and grounded all the earth's together on the back of the cluster to test that theory. I also know I've got voltage to the cluster.


Yes, I pulled the entire dash out, plus the engine harness.... also removed a/c, heater, blower, ABS stuff, cruise control stuff, and a few other things...

 

[cjsupra90]

The M1 connector in the Pre mid 89 (i.e. yellow plugs) is obviously Yellow and has 10 pins

The M1 connector in the post mid 89 (i.e. gray plugs) is well again, obviously gray and has 11 pins.

 

[cjsupra90]

Here, this may help also.

 

[gixxer750]

that was it. come down to mississippi and I'll buy you any kind of cookie you want!

The harness to that was rediculous. It comes out of the main harness(that goes to the same place) on the drivers side of the center console, and runs all the way back to the passenger side in a seprate branch from the main harness. Mine was coiled up in the 500 other wires behind the radio that go to run all my aftermarket stuff.



Thanks guys. I feel stupid after something this simple

 

[jdub]

Nice call CJ

 

[cjsupra90]

gixxer Glad that the problem is solved.


jdub Yeah, I remember dealing with that plug when I was rewiring everything when i went standalone and as soon as I read everything that he lost, thats the first thing that came to mind, remembering that that plug carried every one of those signals.