3rd Gen Rallye Gauge Wiring Issues

[LargerCharger1188]

Hi everybody!

I was a member on here a few years back and just rejoined.  I have searched high and low and cannot find another thread on here or any info elsewhere that helps with my problem, so here it is:

I have a '74 SE with an unoriginal rallye cluster.  When I bought the car it was an electrical nightmare, so I gutted the wiring and spent a good chunk of change and a ton of time rewiring the entire vehicle with harnesses from year one. Its all back together now, it runs, all the lights work etc BUT I cannot, for the life of me, get the gauges to come back to life.  I had taken pics of the old wiring and have hooked it up as close to those pics as I can and nothing.  The gauges all worked before it was re wired. 

I have the original wiring diagrams for the harness from '74, but they haven't been much help.  I'm quite frustrated at this point, especially since the back of the cluster is simply not very complicated.  I've looked for a diagram of the back of the cluster (v. just the wiring diagram with lines and labels) with no success.  Right now none of the electric gauges work.  The re-wiring included a new fuse box and all fuses are good.

I'm stumped

Any help would be GREATLY appreciated, and if anyone needs pics to help figure it out just say so and I'll get them. 

Thanks Everyone! Good to be back!

[chargd72]

My guess, without seeing pictures, would be the absence of or a bad voltage limiter.  It's what powers most of your gauges.

[LargerCharger1188]

Thanks for the reply,

If you're referring to the voltage regulator under the hood mounted on the firewall, I replaced it when I did the wiring... I also replaced the small block with 3 connections thats mounted on the back of the cluster (cant remember what its called).

There is a small cylinder near that block with a wire going to it that I didn't replace, and I don't know what it is.

I'll post a couple pics shortly.

[LargerCharger1188]

This is the right side of the cluster where all non-functioning gauges are. Taken from drivers seat with cluster pulled out and face down.

[Nacho-RT74]

that green stuff attached on cluster is the voltage limiter for gauges. Feeds 5 volts for them

the wire arriving on left prong at pic it comes from fuse box and is feed from accesories source

do you have 12 volts at that wire with key in RUN or ACC ?

the big spade plug with two wire is a grond reinforcement coming from the dash ground point ( just right above the hood or brake handle )... is the limiter good grounded ?

[chargd72]

 

That little box is the voltage limiter.  Should have 12v in and 5v out. 

[LargerCharger1188]

OK, we're certainly getting somewhere, thanks for the advice so far!

The alternator and oil pressure gauges are working, and I have power and a good ground going into the voltage limiter (which is new), However, the fuel and temp gauges are still DOA. I did let the car run sit and idle for about 10-15 minutes to check temp gauge.  the sending unit for the fuel gauge was re-grounded not long ago and worked afterward (didn't work when I first got the car) but it was before the major re-wire.

Any guesses?

Also the new voltage limiter is from rt-eng.com and there's a tiny red LED light blinking on it.  Not sure if that has anything to do with anything, just haven't noticed it before.

[Nacho-RT74]

alternator it works by its own, doesn't have anything to do with voltage limiter

if at least ONE of the guages is working the limiter is working ( yeap we noticed is the RTE electronic unit )

have you unplugged the fuel and temp senders and ground directly to chassis those leads to check if gauges respond ?