Team Camaro Tech banner

1 - 19 of 19 Posts

·
Registered
Joined
·
146 Posts
Discussion Starter #1
Well I can say that I am frustrated...
I have been trying to figure out why my temp gauge is not working (aftermarket gauge package) all other gauges work very well. I am on the second Temp switch ...unit at the block.. and both read the same at 10x ohms about 20-25 when hot. I have tried the TU4 and the one with the threaded end (not sure of the number). Both ohms readings are the same or very close. I have checked multiple locations on the block and radiator with a non contact thermometer ..The engine runs at an even 178-185 all the time. The gauge itself worked a couple of times and that was it. Now it sits on C (cold) and does not move. I checked the ground and it is connected as per the factory (reproduction) wiring from AAW...
1. Do I need another ground?
2. Is there a way to test the gauge...I read something about a 9v battery I think across the gauge green and pink wire connections I think.
I would love to have this thing work even a little..
Any ideas???:confused:
 

·
Registered
Joined
·
1,913 Posts
Re: 1968 camaro guage temp unit not working

Did you put teflon tape on the sender? It can insulate it from the grounded block. Also, try grounding the sensor wire, does the gauge go to it's lowest reading? If not, try the same at the gauge. If it's already reading at the low end, the wire is likely shorted. No 9V battery. You can buy a 100 ohm resistor at Radio Shack and put that across the gauge. Should read somewhere on the scale (not either end). Have fun!
 

·
Registered
Joined
·
996 Posts
Re: 1968 camaro guage temp unit not working

Is it wired like this



If so, if you leave the sender wire off the sending unit, and the key on the gauge should go to cold. If the sender wire is grounded the gauge should go full hot.
 

·
Registered
Joined
·
146 Posts
Discussion Starter #4
Re: 1968 camaro guage temp unit not working

Jim and Dale,
Thanks for the input. Looks like I need to pull the console apart.
No teflon tape on the threads so I am OK there. The gauge itself does not seem to be moving with a grounded wire (on the engine) so I will try Dales suggestion and let you know...
Thanks again...:beers:
 

·
Moderator
Joined
·
14,092 Posts
Re: 1968 camaro guage temp unit not working

Jim and Dale,
Thanks for the input. Looks like I need to pull the console apart.
No teflon tape on the threads so I am OK there. The gauge itself does not seem to be moving with a grounded wire (on the engine) so I will try Dales suggestion and let you know...
Thanks again...:beers:
The gauge also has to be grounded. There are 2 coils in the gauge they pull the needle in opposite directions and the balance between the 2 is the position of the needle.
 

·
Registered
Joined
·
146 Posts
Discussion Starter #6
John
I believe the gauge is grounded to the metal part of the housing and to a black ground wire that was a part of the AAW harness. I think I will open the console up and take a picture and see what you all think. Maybe I have a wire in the wrong spot or something.
 

·
Registered
Joined
·
92 Posts
When I installed my AAW kit the console harness plug was not indexed properly with the main harness. Ensure the green wire is consistent through all the harness connections and check the grounds on the back of the gauge panel.
 

·
Registered
Joined
·
146 Posts
Discussion Starter #8
Brian,
That is my next step. I have posted photos of my connections to the gauge for everyones review. Please look them over.
http://www.cardomain.com/ride/3879999/1968-chevrolet-camaro-ss/page-18
I am hoping it is all good.
I have wired in a purple wire thinking that I might want to run a separate ground to a local spot...any thoughts on this? also do you see any concerns in doing this?
I will let you know what I find for the green wire continuity.

Thanks for all the input everyone...:thumbsup:
 

·
Registered
Joined
·
146 Posts
Discussion Starter #9
All,
Just did an ohms test on the green wire and it is perfect. So far I think we can eliminate green wire and switch/sending unit. So I tested the ground wire for continuity and it is good also ...any other thoughts or do you think its the gauge itself?
Can the pink wire be tested? Does it carry voltage?
Anyone have any luck getting one of these gauges replaced?? I bought the entire console assembly from Rick's.
 

·
Registered
Joined
·
92 Posts
You could also swap the pink and green wires with jumper leads to test and make sure they aren't backwards. I wired my cluster per the drawing in the kit but my aftermarket console gauge cluster leads were backwards. If you disconnect the leads and make a few jumper wires you can test it to see if that is the issue. I tested mine with the engine warm so it only took a few seconds to check.
 

·
Registered
Joined
·
146 Posts
Discussion Starter #11
For the switch itself I have checked the ohms on both switches/sending units
I have...Both at 75 degrees show 50 ohms at 10x...so 500 and both show 250 @125 degree water-160 ohms @ 185 degree when heated. I have seen other places that call this out differently...starting at low ohms and going up. So which is correct?
 

·
Registered
Joined
·
146 Posts
Discussion Starter #12
Brian,
Please look at my photo link and let me know if you think they are backward...If you think so I will check to see if that helps. Thanks
 

·
Moderator
Joined
·
14,092 Posts
Brian,
Please look at my photo link and let me know if you think they are backward...If you think so I will check to see if that helps. Thanks
With the key on do you have 12V to the pick wire at the connection?
 

·
Registered
Joined
·
146 Posts
Discussion Starter #14
I assume you meant pink wire...yes actually a bit over 13V at the pink wire.
 

·
Registered
Joined
·
92 Posts
Joe, The resistance on the green wire from the temp sending unit changes the DC voltage potential to ground causing the change on the gauge. If the pink and green wires are backwards the gauge will always see a low resistance creating a constant cold indication.
 

·
Registered
Joined
·
146 Posts
Discussion Starter #16
I did a jumper wire opposite positions and the gauge did not move. I think it might be the gauge at this point...your thoughts..any and all. Thanks
So in summary:
Green wire has continuity,
sending unit/switch decreases ohms as it gets hot.
Pink wire has 13+ volts with ign. on.
I Have tested gauge with wires in both positions and gauge sits...no movement.

It could be that the wires were on backward since the begining and the gauge is cooked...it could be that the gauge was faulty from the get go...although I remember it moving the first few times I ran the car...just not much movement.
any other ideas out there???? :confused: :sad:
 

·
Moderator
Joined
·
14,092 Posts
I did a jumper wire opposite positions and the gauge did not move. I think it might be the gauge at this point...your thoughts..any and all. Thanks
So in summary:
Green wire has continuity,
sending unit/switch decreases ohms as it gets hot.
Pink wire has 13+ volts with ign. on.
I Have tested gauge with wires in both positions and gauge sits...no movement.

It could be that the wires were on backward since the begining and the gauge is cooked...it could be that the gauge was faulty from the get go...although I remember it moving the first few times I ran the car...just not much movement.
any other ideas out there???? :confused: :sad:
Try a known good gauge. Just pick up a cheapy at the parts store for testing. Once you confirm the wiring is right and it works then wire the gauge you have the same way. If it doesn't work you know it's a bad gauge.

The quality of these repro kit gauges are not very good.

That's why I did this...Very accurate and it cost less.

 

·
Registered
Joined
·
92 Posts
I'd have to agree with John at this point. If the continuity and voltage is good, the gauge is properly grounded, you have swapped wires and you know that the temp sensor is good then I would say the gauge is faulty.
 

·
Registered
Joined
·
146 Posts
Discussion Starter #19
all,
To let everyone know on this. I purchased a new gauge and a new sending unit. I do not think the sending unit was bad but it was the wrong style. I assume it was the gauge because it is working fine now. Gauge reads just below 1/4 mark when engine is at approx 197 deg. Bad thing was that the gauge was a part of a kit and since it took so long to figure this out the supplier would not replace it...had to lay out the cash...again.
 
1 - 19 of 19 Posts
Top