Temp gauge problem...Solved

[90skichallenger]

I have a 1990 Ski Challenger 21' with a indmar converted 351W center mounted inboard. When I turn my key on my temp gauge goes straight to 150 deg. I have replaced the sender on the water pump and it still does the same thing. The gauge seems to work fine it is just starting at 150 so I am not getting good temp measurements as my gauge tops out at 250 deg. I have run up against a brick wall. My ground seems to be good because the gauge uses a common ground with the other instruments and they are fine, I have not physically checked the ground though. It seems to have another sender on the manifold that also bears a striking resemblemce to a temp gauge. I would appreciate any insight ya'll have into this problem. <br />Thanks,<br />I ended up just putting in a new gauge with sender and that fixed it right up.

 

[tommays]

Re: Temp gauge problem...Solved

http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=010466 <br /><br /><br />if you read through this post it covers how to check your problem<br /><br /><br />tommays

 

[90skichallenger]

Re: Temp gauge problem...Solved

Thanks dude

 

[90skichallenger]

Re: Temp gauge problem...Solved

OK I checked all the stuff listed in that e mail.<br />My ground seems good, except what is that thing about the copper ring on the tstat housing. Dont have that just a stock ford tstat gasket.<br />My gauge is working it is just starting at 140 and moving up from there.<br />When I ground tthe tan wire it does indeed jack the gauge past full.<br />My temp sender is good.<br />My waterflow is fine. (checked by backing out the sender until it started dribbling)<br />so can I assume the gauge is bad, and can I replace it with an off the shelf VDO gauge.<br />or is there something else I can check.

 

[tommays]

Re: Temp gauge problem...Solved

did you take and ohm reading on the sender to be sure it goes from goes through its high to low to low range ?<br /><br /><br />the guages and senders need to be matched to some extent different makers units have different ohm values in there units <br /><br />so it is a bit of a guess if a different guage will work with the current sender<br /><br /><br />tommays

 

[trog100]

Re: Temp gauge problem...Solved

the sender is just a heat governed variable resistor.. the gauge which should be matched to the sender reads the resistance of the sender..<br /><br />either they aint matched.. (designed to work together) or one of then is faulty.. probably the gauge..<br /><br />no rocket science here dude.. <br /><br />trog100

 

[waterone1@aol.com]

Re: Temp gauge problem...Solved

If you pull the wire off of the sender and turn on the key does the guage "start" where it should or is it still at 150 ? If still at 150 it is the gauge.

 

[90skichallenger]

Re: Temp gauge problem...Solved

If I pull the wire from the sender the gauge drops back to where it should start, and when grounded does slam to full

 

[90skichallenger]

Re: Temp gauge problem...Solved

And the gauge on it is the original gauge. I did buy the sender from a marine parts store for a 351 w.

 

[waterone1@aol.com]

Re: Temp gauge problem...Solved

That sure sounds like you have the wrong sender.

 

[90skichallenger]

Re: Temp gauge problem...Solved

That is the only sender listed for that application. How the heck do I find another one

 

[Chris1956]

Re: Temp gauge problem...Solved

Jeff, There are two kinds of temperature senders, used on boats. One is intended to be used with a gauge, and the other with a warning horn. The sender used with the warning horn would normally have high resistance until it detects overheating an then it would change to a short to ground. Is it possible you bought the wrong one? The warning horn senders are similar(or maybe identical) to the senders used for Temp idiot lights in your car. make sure the one you are using is for a gauge.

 

[Bondo]

Re: Temp gauge problem...Solved

You Just Might Possibly have to buy the Sender from whom ever built Your Gauge,.....<br />That way the Ohm Factor Will be Correct.........<br /><br />If it's a VDO gauge,.... Call Them for the Answer.............<br /><br />You'll Also need to change the T-stat Gasket to 1 with the brass rivit in it...... That'll give it a Clean Ground...............<br />Right Now,.. You're grounding thru the bolts,....And, That's Not Good Enough...........

 

[90skichallenger]

Re: Temp gauge problem...Solved

Thanks all for the assistance. My ground is good, the gauge checks good and the sender checks good. So I am thinking the sender and gauge are not matched. So I am going to the store to try a different sender. I will let yall know what happens.