More Gauge issues

[n2sking]

I have a 99 Legacy, Over the winter I replaced the exhaust manifolds, I had to remove the heads and cut off the manifolds on the bench. (not a fun job). After reassembling everything my gauges went Haywire. I'm thinking it's a ground issue but I can't find it. This weekend I went through the harness on the back of the head and cleaned and checked everything. I pulled the computer and there was no sign of water or broken o-rings either. (this is my 4th computer so I know where to look) and the boat hasn't been in the water since the head rebuild.

The tach points straight down to 6 oclock, the temp gauge is pegged as well as the fuel, the alt and oil pressure seem to work ok. Any ideas? Does anyone have a wiring diagram?

thanks

[OUI]

It has to be a ground issue. Start somewhere around the motor. When you pulled the heads, something shorted.

[n2sking]

I cleaned and retightened the ground behind the circuirt breaker on the back of the head. Added some dielectric grease for good measure. Checked the multipin plug as well as the connector along the stringer near the starter. Also the main ground on the front of the Port head was done too. late last year I started having issues with the temp gauge, but all the others were fine. Replacing the sending unit didn't help. Is there a ground reference anywhere else on the motor?

[michael hunter]

You didnt hook up you battery backwards ?

[n2sking]

No, battery is good, boat starts and runs good, only the gauges are not working. Radio plays, horn blows, lights work, gauges suck! I'm seriously thinking of converting them all to old school manual gauges and maybe a perfect pass. I even special orded the boat with a carb to avoid "computer" related issues since I run in mostly brackish water.

[CDAHDAH]

n2sking, did you ever figure this out?
Im literally having the same issues, just like you described. Only gauges that work for me are the oil and ampmeter, doesnt make any sense.
My grounds seem fine. Ive even jumped ground and power straight from the fuse block to individual gauges, but no luck.

Any suggestions?

[n2sking]

I never figured it out and it pisses me off. I started having flakey readings from the oil pressure gauge late this summer and I blew it off thinking that gauge was finally giving up and dying like the others, turned out, the engine developed an oil leak around the pressure switch and pumped all the oil out of the engine, and you can guess what happened to the motor before I got back to the dock and figured it out. Now I have to rebuild the motor over the winter and try and figure out what to do with the stupid gauges to make them work. I think that the little servos that drive the needles in each gauge is what went bad, they all went one by one at different times. The OP gauge still works, but all the others are dead.

[Jetlink]

Bummer on the oil leak. I had replaced the oil pressure switch when I first got my boat because the switch was bad, then the new one was faulty and leaked, ended up with a cheap one on there that's just an "on/off" switch, would prefer to have one that tells me what kind of pressure. I ended up either replacing bad sending units or bad gauges which resulted in all new gauges for my helm.