1969 Plymouth temp gauge (Help wiring gurus)

1969 Plymouth temp gauge (Help wiring gurus) - 07/27/13 05:16 AM

Hey gang I'm working the bugs out of my almost completed resto on my 69 GTX.I have a temp gauge that does not seem to do anything. I had the whole cluster restored years ago by one of the bigger gauge companies but I don't remember who anymore. Anyway brand new M&H harness through out entire car. Everything else seems to be working great. I know there's a way to test sending unit with test light, not sure how. What's my next move replace sending unit? How do I go about checking the gauge? I hope I don't have to pull the cluster(pain in the butt)I did make sure the main connector was tight.
Thanks
Joe

Posted By: 6PakBee

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 07/27/13 11:30 PM

If you have the original instrument cluster voltage regulator installed, with the temperature sender wire connected, use a test light from ground to the sending unit terminal. The light should be flashing.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 07/31/13 09:30 PM

Quote:

If you have the original instrument cluster voltage regulator installed, with the temperature sender wire connected, use a test light from ground to the sending unit terminal. The light should be flashing.

Ok I did the following and I have no flashing light at the sending unit when the wire is hooked up.Do I have a dead gauge?How do I test the gauge or could it be a bad sender?
Thanks in advance
Joe

Posted By: pushbutton

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 07/31/13 11:07 PM

Quote:

Quote:

If you have the original instrument cluster voltage regulator installed, with the temperature sender wire connected, use a test light from ground to the sending unit terminal. The light should be flashing.

Ok I did the following and I have no flashing light at the sending unit when the wire is hooked up.Do I have a dead gauge?How do I test the gauge or could it be a bad sender?
Thanks in advance

Could be a bad inst cluster voltage reg. Maybe bad connection at the bulkhead connector.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 07/31/13 11:36 PM

I thought if the instrument voltage reg was bad some of the other gauges would not read correct? Everything works perfect except temp gauge dose not move.I've checked all connections already all seem good and tight,I know the connections are clean,it's all brand new.
Joe

Posted By: 1970_EK2AAR

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 12:01 AM

Disconnect the violet wire at the temp sending unit and connect it to vehicle ground. Turn the ignition switch to the "On" position, the cluster gauge, if operating correctly, with indicate "full" hot. This test procedure works the same for the fuel and oil gauges as well.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 01:40 AM

Ok I grounded out the sending unit wire and turned key on and the temp gauge still does not move,stuck on cold. For what it's worth I took a test light to back of temp gauge and one side has a blinking light the other side of gauge has nothing? Bad gauge?

Posted By: screamindriver

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 01:50 AM

Don't call it a bad gauge just yet...The blinking light means your voltage limiter is working and supplying current......Make sure you have a good connection between the bulkhead terminals for the sending unit wire... If that checks out then you can test the gauge and see if you have a range of motion...

Disconnect the gauge from the cluster wiring and use 2 C or D batteries to get 3 volts...Then connect it to the gauge{pos to limiter post,neg to sender post}...If it's good it should come up to about half way or a little better with the sweep...

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 02:20 AM

Quote:

Don't call it a bad gauge just yet...The blinking light means your voltage limiter is working and supplying current......Make sure you have a good connection between the bulkhead terminals for the sending unit wire... If that checks out then you can test the gauge and see if you have a range of motion...

Disconnect the gauge from the cluster wiring and use 2 C or D batteries to get 3 volts...Then connect it to the gauge{pos to limiter post,neg to sender post}...If it's good it should come up to about half way or a little better with the sweep...

Ok do I need to pull the gauge out of the cluster? If so does the whole cluster have to come out of the dash to get the gauge out? It's been a couple of years since I put it together. Could I leave the gauge in place and disconnect the battery and put alligator clips on the gauge posts and hook it up to the D or C batteries like you explained?
Thanks
Joe

Posted By: Pacnorthcuda

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 02:26 AM

Quote:

Quote:

Don't call it a bad gauge just yet...The blinking light means your voltage limiter is working and supplying current......Make sure you have a good connection between the bulkhead terminals for the sending unit wire... If that checks out then you can test the gauge and see if you have a range of motion...

Disconnect the gauge from the cluster wiring and use 2 C or D batteries to get 3 volts...Then connect it to the gauge{pos to limiter post,neg to sender post}...If it's good it should come up to about half way or a little better with the sweep...

Ok do I need to pull the gauge out of the cluster? If so does the whole cluster have to come out of the dash to get the gauge out? It's been a couple of years since I put it together.
Thanks
Joe

No! screaming is right. You just have to have access to the terminals. Juggling two 1.5 volt batteries can be a pain. Even ONE battery will cause the gauge to move if the gauge isn't dead.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 03:48 AM

I think my gauge is DOA

So I taped two D batteries together and checked it with a test light which was dim so I know I had them together good.I ran two leads two the gauge posts and hooked them to the batteries,NO movement at all. So what all do I have to tear apart to get my gauge out?

Posted By: 1970_EK2AAR

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 12:05 PM

Unfortunately the cluster assembly must be removed from the dash frame in order to remove the gauge. Whether a base set-up or Rally, the removal process is the same. Once the instrument cluster module is on the bench, the trim is removed, the push pins lifted and the clear lens is separated. Now remove the gauge stem nuts from the circuit board connection and the individual gauge is finally in your hands.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 03:17 PM

Ok thats what I figured would need to be done.One last idea on this matter,does it matter which side the two wires on the back of the gauge go?? Could I have the wires switched on the gauge itself??
Thanks for the help
Joe

Posted By: JohnRR

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 06:34 PM

Quote:

Ok thats what I figured would need to be done.One last idea on this matter,does it matter which side the two wires on the back of the gauge go?? Could I have the wires switched on the gauge itself??
Thanks for the help
Joe

yes it will matter .

Have you used your meter to confirm continunity between the sending unit end of the wire and the other end under the dash ? This wouldn't be the first time an M+H harness had a crossed wire.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 09:33 PM

John I do not have my multi meter home at this time,just a test light.I can grab one and check from under the dash to sending unit to make sure I'm good there. Can you tell me which color wire goes to what side of gauge,or what side of the gauge should be blinking.

Posted By: pushbutton

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/01/13 10:10 PM

Setting in the drivers seat the right side stud should blink. If it's crossed under the dash it would be in the multi pin connector. The cluster I looked at was a 68 but I would think they would be the same.

Posted By: Firepowerflyer

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/06/13 02:05 AM

Quote:

Setting in the drivers seat the right side stud should blink. If it's crossed under the dash it would be in the multi pin connector. The cluster I looked at was a 68 but I would think they would be the same.

I checked what side of my gauge is blinking and sitting in the driver seat the right side post is blinking. I have not check continuity all the way to the sender yet, I double checked all the connections. I looked at the schematic and the multi pin connector appears to wired correctly. I'm leaning towards a bad gauge unless I'm missing something.

Posted By: pushbutton

Re: 1969 Plymouth temp gauge (Help wiring gurus) - 08/06/13 02:21 AM

Quote:

Quote:

Setting in the drivers seat the right side stud should blink. If it's crossed under the dash it would be in the multi pin connector. The cluster I looked at was a 68 but I would think they would be the same.

I checked what side of my gauge is blinking and sitting in the driver seat the right side post is blinking. I have not check continuity all the way to the sender yet, I double checked all the connections. I looked at the schematic and the multi pin connector appears to wired correctly. I'm leaning towards a bad gauge unless I'm missing something.

Check to make sure the sending unit is getting a ground. Not too much thread sealing compound Teflon tape or paint in the threads.