Temperature Sender.. Voltage stabilizer

[sizod]

Spend a good few hour looking for information on the temperature sender. My truck 73' Series III is running hot this past week. I replaced the water pump and hoses a few months back back flushed, timed and tuned etc etc. its been running great. End of june when we had those humid days in RI the truck started to run hot, it would slowly edge its way up toward the red line. it never reach it, by the time i get home from my commute its a 1/4inch from the red just above the "N". I tested the Ohms and as some one else posted. It appears to be giving the correct reading. I have an alternator on the truck which is newish so I don't have a separate voltage regulator/Stabilizer because its on the alternator correct? If I'm wrong where would it be? The Fuel gauge is accurate, so it would seem that would rule it out. when I was checking the ohms on the sender I test the voltage to the sender which was 13v when running. All the posts seem to say that it should be 10v. is that correct? The thermostat that is in the truck is I believe a 74. when the truck is hot the top hose doesn't seem rock hard. i stuck a meat thermometer in the radiator and it read 80c, put the cap back on, waited and the the hose was still somewhat pinch-able. should it be rock hard if the thermostat is open? Radiator is i believe the original. I'm going to get a laser thermometer tomorrow and see is there is any temp differences across the radiator, see if there is a blockage.

Sorry for all the question. Am I on the right path.... thanks

[SafeAirOne]

If you are getting 13v from the disconnected wire at the temp sender than your voltage stabilizer is bad, though some ex-MoD trucks didn't use them. Not sure which ones, but I don't theink any were SIIIs.

Anyhow, it's been my experience that the temp gauge is more sensitive to overvoltages than the fuel gauge for whatever reason. The voltage regulator in your alternator is something completely different.

The instrument voltage stabilizer changes the 11.7-14 volts the truck is producing to a steady average of 10 volts for the 2 instruments.

On a series III (or on my SIII at least) you can find the voltage stabilizer (a little metal rectangular cube) screwed to the backside of the speedometer housing. Some of them may be mounted directly to the bulkhead behind the instrument panel, I think. Just have a look around. RN says they're no longer available but RDS has them along with a million other places. Looks like this except without the little LED:






Note that the stabilizer is grounded through the mounting screw and if the contact with the speedo housing is bad or the speedo and other gauge cluster isn't properly grounded, you can get false high readings with the instrument panel and exterior lights on. In other words, make sure the stabilizer case is well grounded.

[sizod]

Thanks for the info.. RDS doesn't have any in stock. I did stumble upon this document about testing adjusting or making a solid state one. SmithsVoltageStabilizer.pdf

I could seem to find any vendor that had any in stock for the series that were in the US. AB had the but they look different Voltage regulator 7013 you think it the same thing?

If not I'll order one from the UK.

[SafeAirOne]

AB had the but they look different Voltage regulator 7013 you think it the same thing?

No. That's a voltage regulator for an alternator. You're looking for an instrument voltage STABILIZER. If you are even slightly electro/mechanically inclined, you can build your own everlasting solid-state version for about $5 presuming you already have a soldering iron. See: http://www.britishv8.org/Articles/MG...Stabilizer.htm

EDIT: Just had a good look at the link you posted--That's a great article on the voltage stabilizer!

[knac1234]

sizod,

Lot's of old Brit cars have these---all 4 of mine do! Just order one from Moss Motors for $16:

http://www.mossmotors.com/graphics/products/PDF/131-555.pdf

Regards,
Julian

[SafeAirOne]

Just order one from Moss Motors for $16

That's a good price for a stabilizer that'll last longer than your rover.

[antichrist]

Here's some detailed info on the stabilizers, diagnostics and replacement.

http://home.mindspring.com/~purlawson/files/SmithsVoltageStabilizer.pdf

[leafsprung]

If our hosts cannot help you with an original unit - I can

[sizod]

Thanks for all the info... I bought a solid state one from Moss motor. I might try to make my own with the old one i'm pulling off. Hopefully thats the fix. Its a lot cheaper than a new radiator.

[sizod]

Got the new voltage stabilizer and installed it. its about 90 50% humidity drove it around 45 mins did some hills, freeway, stop and go traffic plus I had a somewhat heavy payload. Temp gauge barely moved off the white now. Does this seem correct?

Also filled the tank and now the highest the fuel gauge reads is just over 3/4 mark, its always read off the chart when full. ground issue maybe?

[artpeck]

It is like we are living parallel lives with this issue. Finally bought an infrared thermometer and confirmed that the truck was running fine. But it still bugs the crap out of me that it reads hot, sometimes...