Gauges reading wacky or not at all

[CUDA JAS]

I installed rallye guages in my Cuda this spring.

The temp guage does not read at all.

The gas guage usually pegs at the full side, but will sometiems fluctuate down. 

The gas gauge and fuel sender are new, so it should work.  The temp guage I do not think I checked. The oil press guage is not hooked up yet.

So, I was thinking the proble could be the old wireing (especially the fuel gauge). 

My plan was to run a jumper wire from the fuel sender tot he guage and see if it reads properly.  Then try the same with the temp guage. 

I was reading an old article today and is says these symptoms are somtimes caused by the stock regulator. So I think I will try a test light on the regulator first

Any other thoughts, or am I on the right track?

[Bullitt-]

Could be wiring or a myriad of individual issues... First thing to do is ground the wire from each sending unit & see if each gauge pegs.  If that works on any of them you know the gauge is fundamentally working and your regulator is probably good. Each sending unit can be checked but you will need an ohm meter.. If each sending unit checks then it's down to wiring, in the case of the tank a separate ground from the frame to the sending unit often solves problems.

The service manual gives no values for the temperature & oil sending units but you should get continuity through them..if open then they are bad for sure.
Fuel sending unit is empty 73-ohms +/-12
                           full     9.6-ohms +/-1

[CUDA JAS]

Thanks man.

looks like I am screwed.

I grounded the gauges both at the sender wires and directly to the post on the gauges. Temp guage doe nothing.  Fuel gauge went up to 1/8 or so and then went back down.

I am getting power into and out of the regulator (not sure how many volts (will check that later)).

Looks like I am pulling out the guages and replacing a few.   

[miketyler]

I think the regulator should output 5V. It is an old school design, and there was an article somewhere about how to build a replacement using current technolgy components   

[Chryco Psycho]

the regulator pulses & provides approx 5 v you can teat this with a test lightgoing into & out of the guage without removing them , you could have a problem in the wiring after the guage

[CUDA JAS]

the regulator pulses & provides approx 5 v you can teat this with a test lightgoing into & out of the guage without removing them , you could have a problem in the wiring after the guage

My test light is on constanly (no pulse) on both the in and out of the regulator.

I am guessing my gauges are now screwed!!!

Jas

[miketyler]

I wouldnt give up yet. Do you have a VOM that you can test and confirm you are getting 5V DC? Also, try running a good body ground to each gauge and see if that makes any difference

[JayBee]

As I was reading through this I noticed something wasn't mentioned, maybe it's just a given and common knowledge BUT after you grounded the wire going to each sending unit did you have the key in the "ON" position.

[Bullitt-]

Just a thought...Not sure on this, but doesn't the regulator have to be grounded to work/& test properly...seems I recall this being an issue.

[Chryco Psycho]

yes the reg has to be properly grounded

[dodj]

I'm assuming you have two regulators now. One from the old cluster and one from the rallye cluster. If the original one was working, try swapping them, they are the same. The original regulator pulses on and off like Chryco said. If it doesn't, it has a poor ground or is broken. Below is a link to making your own solid state regulator.


www.imperialclub.com/Articles/GaugeRepair/