engine temp guage

[pushrod_POWA]

hey,
I am currently having issues with my engine temp gauge. It reads max heat from the start. I first thought that it was the temp sender so I replaced it. However it stil read max. I searched and found that some one else had this problem (turned out to be the wire earthing) so I traced my wire but I couldnt find any damage in it or any extra earthing. Any ideas what it could be? i need to fix it so i can get a blue slip. It on a ke55 by the way.

[slide86]

you might have a faulty cluster or gauge its self. by what you are saying, it sounds like its earthing out, but it could have an internal fault in the gauge. might have to go to a wrecker and get another gauge to test it.

[pushrod_POWA]

thanks heaps for your response.

I'll keep looking for a place where it might be earthing out. Im guessing that it would be more common where it goes through the fire wall?

[Mr Ed]

If the sender isnt earthing the signal will show a cold engine, not hot. Sounds like a faulty gauge to me too.

[pushrod_POWA]

If the sender isnt earthing the signal will show a cold engine, not hot. Sounds like a faulty gauge to me too.

How sure about this are you? 100%?

[Norbie]

If the sender isnt earthing the signal will show a cold engine, not hot. Sounds like a faulty gauge to me too.

Yes, but if the wire between the sender and the gauge is shorting against the body somewhere (ie permanently earthed) the gauge will read hot. More than likely that's what's happening here.

The best way to check is to disconnect the signal wire at the sender, and use a multimeter to check resistance from the signal wire (at the gauge end) to the body. If the resistance is low (ie closed circuit) you have damaged wiring somewhere.

[Fish]

i have had problems were the guage would read hot if i did not have the extra earth connected but thats with a splitfire gauge

[oldcorollas]

Yes, but if the wire between the sender and the gauge is shorting against the body somewhere (ie permanently earthed) the gauge will read hot. More than likely that's what's happening here.

The best way to check is to disconnect the signal wire at the sender, and use a multimeter to check resistance from the signal wire (at the gauge end) to the body. If the resistance is low (ie closed circuit) you have damaged wiring somewhere.

echo...

does the gauge read hot with the sender disconnected?
if yes, there is problem between sender and gauge.
if no, and you check resistance of sender to be ok, then there is problem with gauge or gauge earthing/wiring.. the gauges usually have a common earth point from the cluster tho.

[mrshin]

Check all other earth wires on the car are connected - I have some memory of a similiar problem on a KE55 a few years ago, and it turned out to be a disconnected earth someplace else I think.

[pushrod_POWA]

Check all other earth wires on the car are connected - I have some memory of a similiar problem on a KE55 a few years ago, and it turned out to be a disconnected earth someplace else I think.

Ok I will check that next.

I did find that the copper wire on the cluster was open but that was fixed with a bit of soldiering (sp) but that has only slowed the needle from rising as fast. It stil reaches max but It takes longer now.????

thanks for all the help so far

[Mr Ed]

Yes, but if the wire between the sender and the gauge is shorting against the body somewhere (ie permanently earthed) the gauge will read hot. More than likely that's what's happening here.

The best way to check is to disconnect the signal wire at the sender, and use a multimeter to check resistance from the signal wire (at the gauge end) to the body. If the resistance is low (ie closed circuit) you have damaged wiring somewhere.

True, good point. Id +ve rep ya for that but the damn system wont let me cos youve helped me too much, too frequently!!!

[Mr Ed]

How sure about this are you? 100%?

Yes Im 100% sure of that.....except Norbie's point is probably more relevant to your problem.

[mic*]

Ok I will check that next.

I did find that the copper wire on the cluster was open but that was fixed with a bit of soldiering (sp) but that has only slowed the needle from rising as fast. It stil reaches max but It takes longer now.????

thanks for all the help so far

Can you explain more how you've fixed an insulating prob with solder?

Sounds like you might have created more resistance between the gauge and the problem descibeed above.

As said, what happens when the sender is disconnected? If it still goes hot try running an external wire from the sender to the gauge to isolate the problem. (You would have to pop the pin out of the clip at the gauge so the posiible earth leak does not still exist.)

[pushrod_POWA]

Can you explain more how you've fixed an insulating prob with solder?

I soldiered a wire to bypass the damaged part.

As said, what happens when the sender is disconnected? If it still goes hot try running an external wire from the sender to the gauge to isolate the problem. (You would have to pop the pin out of the clip at the gauge so the posiible earth leak does not still exist.)

It goes down when the sender is disconnected

[Fish]

i'm starting to think a fualty sender?