Dash Gauge Ground? - 1973 K10

[sokoloka]

I recently purchased a '73 K10 off Craigslist and am slowly working through the issues - luckily nothing major.

However, none of the gauges work (fuel, ammeter, speedometer, etc). There are no dash lights either, and I'm assuming there must be. The turn signals, headlights, and electric cooling fans work, so there is life in the electrical system.

Speedometer is hopefully a new cable. As for the other gauges, I'm guessing there is a bad or NO ground in the cab. The truck came with a very ****tly wired stereo system, so whoever had this truck before had some issues with electrical.

Where would I start looking for grounds in this truck to either clean or re-attach?

 

[blazinzuk]

So no gauges work at all?

Did you check and see if they are actually hooked up?

The speedo should work regardless if the speedo cable is hooked up as should the oil pressure gauge.

Both are mechanical in a stock 73

 

[dyeager535]

Just to talk to the gauge grounds, on at least the later trucks, the ground point was on the drivers side behind the dash, underneath the A-pillar, above the kick panel.

If nothing works on the gauges, outside of the mechanical problems pointed out, then I'd suspect the plug on the back of the cluster isn't making contact. Would explain why the speedometer isn't working, if someone had it apart for whatever reason and didn't connect things back up right. To get the cluster out, you have to disconnect both the IP (Instrument panel) connector, and the speedometer.

 

[sokoloka]

So no gauges work at all?

Did you check and see if they are actually hooked up?

The speedo should work regardless if the speedo cable is hooked up as should the oil pressure gauge.

Both are mechanical in a stock 73

Speedo cable isn't hooked up. Oil pressure gauge might work, haven't noticed any fluctuation.

Here's a picture of the back of the gauge panel:

What a freakin' rats nest.

 

[dyeager535]

Thats the wrong cluster for a '73 AFAIK, that speedo cable connector is the later style. I'm not big on the pre-'81 trucks, but I'm fairly certain ones as early as yours should thread on.

That being the case, I wonder if the problem isn't that the cluster pinout doesn't match the wiring connector? I know on the LATE ones ('90-91 at least) GM changed how the circuit "board" was laid out, maybe that happened sometime after the speedometer cable changed too?

Lots of assumptions here, some of the '73-ish truck owners here should probably know for certain.

 

[dremu]

Thats the wrong cluster for a '73 AFAIK, that speedo cable connector is the later style. I'm not big on the pre-'81 trucks, but I'm fairly certain ones as early as yours should thread on.

That being the case, I wonder if the problem isn't that the cluster pinout doesn't match the wiring connector? I know on the LATE ones ('90-91 at least) GM changed how the circuit "board" was laid out, maybe that happened sometime after the speedometer cable changed too?

Lots of assumptions here, some of the '73-ish truck owners here should probably know for certain.

My '74 has that style speedo cable, pop on with a retaining ring, so this could easily be correct for '73.

Interesting point about the connector -- they are indeed different for
"gauge" vs "warning light" (aka idiot light) clusters. In fact there's maybe four variations, as I recently discovered.

To the OP, you might post up a pic or description of the gauges. My cluster had, I forget, amp in the upper left, then oil pressure, fuel gauge in the bottom left, and then water temp in the lower right I think. There was also a clock, or the brake warning light, or any number of other possibilities.

Then we do a pic or description of the plug and its wires. This latter is a royal pain, I know ... here's a lousy pic of one side of mine:

http://www.slosh.com/ck5/PB1400061.JPG

You can sorta see that the pins are labelled 10 through 18, and 14-17 don't have wires. If you post up what colors yours has for each # on the plug, I can compare it to the factory diagram and tell you what the truck is wired for (and mostly, what wires are what.)

You can also look in the glove box and if the RPO sheet is there you can maybe determine what the truck is supposed to have, gauges or lights or what, but the wiring will be the only 100% accurate way to tell.

-- A