Temp gauge issues--needle jumps GRND, but...

[jacko137]

1977 MCM 120

I've been posting since I bought this 1977 Aristocraft in January and I want to start with a HUGE thank you to iboats and guys like Bondo, Don, Ziggy, etc. for all the direction. After nearly giving up MANY times, I actually boated this past Tues night. Really awesome and it wouldn't be possible without this forum.

Tonight's question: many gauges still not working, but current priority is Temp for obvious reasons. Now that I have her running well, I want a handle on things.

If I ground the wire to the back of the sender with a screwdriver, the gauge jumps all the way up, so I believe gauge and wiring is good. I just put in a new temp sender and still no luck. Any suggestions?

Here's a before and after for the hell of it

 

[Don S]

Re: Temp gauge issues--needle jumps GRND, but...

1. DO NOT use Teflon Tape on the sending unit. it must make a good ground where it's threaded in.
2. Check the wiring (with an OHM meter) between the gauge and the sender to make sure it's OK.

 

[jacko137]

Re: Temp gauge issues--needle jumps GRND, but...

1. DO NOT use Teflon Tape on the sending unit. it must make a good ground where it's threaded in.
2. Check the wiring (with an OHM meter) between the gauge and the sender to make sure it's OK.

I didn't add any tape--just installed it straight up with the red gunk that came on the unit.

It sounds like a OHM meter is going to be my next purchase. Any idea what it should read?

 

[Bondo]

Re: Temp gauge issues--needle jumps GRND, but...

Ayuh,...

Groundig the Sender's Wire, rather than the back of the Gauge will tell you if the Wiring is Right...
It should Peg the gauge...

 

[jacko137]

Re: Temp gauge issues--needle jumps GRND, but...

Ayuh,...

Groundig the Sender's Wire, rather than the back of the Gauge will tell you if the Wiring is Right...
It should Peg the gauge...

Ah-ha. I'll give that a shot. Thanks!

 

[ziggy]

Re: Temp gauge issues--needle jumps GRND, but...

Groundig the Sender's Wire, rather than the back of the Gauge will tell you if the Wiring is Right...
It should Peg the gauge...

with the ign sw. in the run posistion.....

the other half of the gage test is to remove the send wire (book says at back of gage for both tests, though i don't know why ya couldn't do it at the sender too). then turn the ign. sw. to run. gage should be full left. anti pegged even.... if gage don't react proper to test. full peg, and full anti pegged. replace gage....

before i'd replace the gage, assuming your removeing the send wire at the sender. i think i'd test the sender wire too like dons suggests. that's where your vom might come in handy....

way to go jacko137 on getting another nineteen back on the lake.... cool man. she is looking great in yer pics.......nice clean, proper looin engine too.... ya should be real happy with yourself for a job well done.......

 

[jacko137]

Re: Temp gauge issues--needle jumps GRND, but...

way to go jacko137 on getting another nineteen back on the lake.... cool man. she is looking great in yer pics.......nice clean, proper looin engine too.... ya should be real happy with yourself for a job well done.......

Thanks Ziggy. I'm pretty pleased myself. But again, I couldn't have done it without you guys. And because she is 32 years old, I'll be needing this forum more than ever to keep her in the water!

I'm going to try and tackle that gauge tonight and see what I can find out. Thanks for the advice.