Engine Temp. gauge

[hondarider188]

I have a 1983 chevy k10 with a a 5.7L engine my temperauter guage didnt work at all when i got the truck. i found a wire hanging on the side of the Head and i saw a plug right next to it so i hooked them up, and then my temp. gauge maxed out. So i believe it is shorting out somewhere and would it have to be in the switch since it wasnt maxed out before? So just need a new switch, right?

[bd]

Playing it safe, can you post a pic of what the 'wire' is plugged into?  Describe what the gauge does when you unplug the 'wire' while the ignition is ON.

[bake74]

      Just pointing out a safety tip here.  In the future if you do not know what a wire is or a plug next to the wire, it is safer to find out first before just plugging things together and turning on your truck.
      We do not want to find out that your truck caught on fire.   

[Jason S]

I agree with the posts above, you might share a photo of what you have.  It could be simply a bad temp sending unit or the wrong year sending unit, but since you asked more information would be nice.

[hondarider188]

heres a picture of the wire and gauge, It is on the driver side of the engine. I was about 90% sure that they did go together Because the wire was hanging beside it not removed or pulled back, and it is a different connection because it has to slide down on top of it and i didnt see any others anywhere that were like it.

[bd]

Several points to be addressed in sequence.

Verify the following...

• Unplug the green wire with the key ON - the temp gauge needle should drop all the way to the left to Cold.
• With the wire still unplugged and the key still ON, jump the green wire to a good ground - the gauge should pin to the right well past Hot.

If the gauge responds as above, replace the sending unit.  Be sure to pick up a sender for gauges (it's different than the switch used with idiot lights).
If the gauge does not respond as above, update us.

• The green sender wire is too close to the exhaust - the insulation will burn and become brittle.  Move it to the other side of the valve cover next to the intake and drop it straight down to the sender.

[hondarider188]

Ok thanks bd ill try and get to it tomorrow and what do you mean by the other side of the valve cover exactly. Do you mean to run it along the other hand screws by the carb and down to the a/c condsensor and around or ?

[bd]

...what do you mean by the other side of the valve cover exactly. Do you mean to run it ... by the carb and down...

I think you're getting the idea... just make sure it doesn't interfere with the carb linkages or throttle cable connection.  You need to reroute the wire away from the exhaust.

[hondarider188]

OK i might have to splice in some more wire though i don't think that it is long enough. It doesn't seem to close to me though it has probably about 2" on each side. And if i do need to reroute it where do i take it from around the exhaust

[bd]

I'll try to snap a pic tonight (and post tomorrow) to give you an idea of the routing.  You shouldn't have to extend the wire to use the factory routing.

The wire is too close to the header as it crosses over the two center tubes.

[hondarider188]

all right im starting to see more of what you mean, ill look for the pic tomorrow so i can get it done. thanks

[bd]

See how the green temp sender wire drops down over the valve cover, just forward of the oil filler cap.  That's a fairly common routing on the small block.  An alternative is to run it around the front end of the valve cover then down, but that would require lengthening the wire.

You may need to anchor the wire to the intake at the point it makes the 90 turn over the top of the valve cover.

(Image courtesy of Lt.Del)

[hondarider188]

All right that seems to clear things up a bit more. So i want to run it along where the valve cover and intake manifold meet and once a i reach down to where the oil fill cap is make a 90 over top of the cover and straight down to the sending unit. that is about how mine is now except instead of running all the way to the oil cap it just jumps straight across about where it would line of with the master cylinder.

[hondarider188]

I did the test that bd had suggested and the gauge didnt react at all. So could it be grounding somewhere else or is it just the gauge?

[bd]

I'm trying to understand what you're telling us.  So with the ignition switched ON, when unplugging the sender the gauge doesn't move left to cold?  Then grounding the sender to a known good ground (key still ON) the sender doesn't move all the way right, past hot?  In both cases the gauge doesn't move at all?  That contradicts your first post...

...my temperauter guage didnt work at all when i got the truck. i found a wire hanging on the side of the Head and i saw a plug right next to it so i hooked them up, and then my temp. gauge maxed out....

Did you make any changes to the green sender wire besides rerouting it?

What does the gauge do if you plug the green wire back into the sender?