Volvo temp gauge and sender

[robmatheson]

The temp gauge and/or sender on my Sealine 218 has failed. I can't find the sender on the engine (VP AQ205A) or the exhausts - so I can't trace the problem. Anyone any ideas where it might be?

Thanks

Rob

 

[Peanuts]

Rob

I'll talk to you, if my memory is correct (not off to a good start really) the temp sender is on the port side of the engine, so standing at the front of the engine looking aft hang over the right hand side of the exhaust manifold and you should see the temp sender - hopefully

What is the problem you are having?

 

[robmatheson]

Thanks

It was working a season ago. Then, one time, I ran up the engine, the needle climbed into the red and fell back. Plenty of oil in the engine, water-cooled through the outleg etc. Now when the ignition is off the gauge needle sits slightly into the lower end of the green. When ignition is on, it falls back to zero.

On first glance it looks like it's been cross-wired. But that's not the case because it was working fine before.

This is a naive question I'm afraid. What does the sender look like?

Any suggestions would be most helpful.

 

[Peanuts]

Hi

Don't really understand why you are not getting many replies to this one.

First of some questions, you state that it worked a season ago, are we talking last year? so how long has it sat dormant?
Was the system flushed through and inhibited before storage?
Is there any reason for the temp sender not to be working, has anyone been rewiring anything?

If every thing has been OK up till now and I assume you were running the engine on muffs, if that is the case did you have the forward inlet hole on the bottom of the leg blanked off? a lot of water can escape out of that so you might not have had enough water going through the engine, either blank that hole with a piece of tapered dowel or get someone to place finger over it (wearing waterproofs, them not the finger) and run the engine again, better still try and find large tub to place outdrive in and fill with water.

If the impeller has not been changed or you don't when it was then I would also take that out and inspect it, replace with new one if worn/damaged.

The final part would be to check the exhaust risers, they corrode on the inside blocking the water ways, sometimes you can clean then out but it usually only gives you an extra year before replacements are needed.

The temp sender by the way looks like a large nut with a terminal in the middle of it, hopefully with a electrical cable connected to it. Sometimes there are 2 cables if you have an alarm as well as a light.

I hope this may help you.

 

[robmatheson]

Thanks

This is a great help.

To try to answer your questions: The last time it worked was in the early part of last season. Then one day I started the engine and the gauge needle rose steadily and quickly to the red, then fell back - dead. I subsequently had problems with her cutting out at slow speeds (turned out to be a hole in the exhaust manifold causing the engine pressure to drop). Once fixed she ran fine - but, with no temp gauge, I was wary of taking her too far - and by the time she was mended there wasn't much of the season left. When she came out in October, the engine was winterised and flushed through with anti-freeze. The impeller was checked, found to be fine and therefore not replaced.

Before putting her back into the water (last Tuesday) I ran her up with the muffs and the inlet hole blanked. She started second time and ran beautifully. Not a flicker from the temp gauge though.

On the day she went back in, I ran her for about ten minutes on the berth, then took her out for half an hour on the Clyde. Again, she sounded lovely and handled well at slow speeds - as well as lifting onto the 'plane with little effort.

So the engine seems fine, the leg is fine - it just seems the temp gauge, or sender , is broken.

I'll have another look for the sender this weekend and see if I can trace the problem from there.

I really appreciate you taking the trouble to help - perhaps I've been asking too many questions

 

[lovezoo]

Have a look on here in the support section. There is a troubleshooting guide for guages. With a multimeter you should be able to determine where the problem is.

http://www.faria-instruments.com/

 

[robmatheson]

Thanks Lovezoo

This will be a great help.

 

[PaulGooch]

This will be a great help.

If you are unsure if it's the guage or sender (most likely the sender) you can take the wire off of the gauge, that goes to the sender, and connect a negative supply to this terminal. If the gauge reads red hot, the sender is shot.

 

[robmatheson]

thanks Paul

I'll give that a go