Help Replacing a Water Temp Sensor

[agt]

Team- 

 

Can anyone please let me know how to replace a water temp sensor? My gauge stopped reporting temperature, a mechanic took a look a while ago and said I needed a new thermometer. Having a bugger of a time finding a how-to on replacing the thing. 

 

Thanks again Ratsun (and again)- 

 

 

[laotsu]

Its on your thermostat housing. Unscrew it. Beat the old one out insert new one and screw it back in . Really easy.

[Tristin]

Find youre radiator. Follow the upper coolant hose towards your engine. Once you see where it connects, go down a few inches and you should see a single wire leading to a plug screwed into your thermostat housing. Then follow Laotsos post. I believe the wire is yellow or yellow white on trucks. 

[datzenmike]

The wire is Yellow/White stripe.

 

Ground it to the thermostat housing with key ON and the gauge should read full HOT if the gauge is working.

 

If the fuel gauge is also not working then it could be the voltage regulator in the dash.

[banzai510(hainz)]

Ok be carfeul as thes things been in there 40 years and most like it will crack the housing when trying to pull the 16mm hex ring off to get the sender.

 

I alwasy try to find a spare (housing and hex nut) first before attempting to do this so you can still drive the truck.(long as you know your truck dont overheat.

 

 

I seen some senders are pre threaded where you dont need the hex ring as it built in the sender.

 

ck out rockauto.com for photos

 

 

PS this is for a L motor 521.

If you have a J motor 1300 I DONT KNOW

[laotsu]

If the fuel gauge is also not working then it could be the voltage regulator in the dash.

THREADJACK MOTHAFUCKAS, NOBODY MOVE!

D-Mike, got any oics of the voltage reg? You may have just told me why my gauges aint aworkin.

[DanielC]

In this picture,

 

The rectangular with the words "Voltage Regulator" on it.  Yours most likely will not have these words.

[laotsu]

In this picture,

 

The rectangular with the words "Voltage Regulator" on it.  Yours most likely will not have these words.

thanks Daniel. We now return you to your regularly scheduled discussion of the 521 temp sensor replacement already in progress.

[banzai510(hainz)]

both both aint working just try tapping on it. Mine works and donsnt work soemtimes but most of the time thats it the Volt reg

[datzenmike]

Daniel, I do now have a picture of it. All I have is the 620 and the 720 VRs.

 

If you carefully remove and pry the metal tabs back you can take it apart. There will be a set of points and a wire wrapped around them. When the wire heats the metal strap it bends away and the contacts open, it cools and makes contact again. Just slip a small folded piece of 600 sand paper between the contacts and pull it out slowly to clean them.

[jwerty1]

I might just label my voltage regulator, that's a good idea :rofl:

[MikeRL411]

Daniel, I do now have a picture of it. All I have is the 620 and the 720 VRs.

 

If you carefully remove and pry the metal tabs back you can take it apart. There will be a set of points and a wire wrapped around them. When the wire heats the metal strap it bends away and the contacts open, it cools and makes contact again. Just slip a small folded piece of 600 sand paper between the contacts and pull it out slowly to clean them.

 

If you do sand the points, you can prolong the time until the next sanding if you burnish the points.  Any slick magazine cover will do.  Tear off a strip and saw away across the points.  This removes microscopic high points and will reduce the tendancy to arc over on opening.  This arcing is what welds the points.  Old teletype printer repair man's trick.  [Teletype - an inkjet printer without the ink jet]

[laotsu]

Old teletype printer repair man's trick.  [Teletype - an inkjet printer without the ink jet]

HAAAA! Teletype I saw one of those on The Streets of San Francisco once. The thing was the size of a chest freezer and sounded like an M-60 tearing up the jungle when it was printing.

[laotsu]

so I sanded the points today and both gauges still don't work, now one side of the volt reg points has a major divot burned into it so deep that the other side sinks into it perfectly.   I also tried grounding the temp wire with the key on and still got no reading.

[MikeRL411]

 

so I sanded the points today and both gauges still don't work, now one side of the volt reg points has a major divot burned into it so deep that the other side sinks into it perfectly.   I also tried grounding the temp wire with the key on and still got no reading.

 

That's why you have to burnish the points! Now on to the VR.

[edekalil]

Just wondering if the 510 has the same regulator?

[laotsu]

yes it does, you need one?

[MikeRL411]

Just wondering if the 510 has the same regulator?

 

The 510 does, and if you can find one, the 410 and 411 VRs have a slightly different bend to the grounding tab.  Either bend the 410 / 411 tab or add a short jumper with appropriate tabs fron the 410/411 tab to the ground connection on the mother board.