• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Gauges...?

Share this page

HighAltitudeTR3

HighAltitudeTR3

Jedi Trainee
Country flag
Offline
I have two gauges out and I realize they are totally different systems, but I am having trouble fing answers on these:

I do not get any reading from my Ammeter. It's connected as it should. Do these go bad? I peeked inside and it looked pretty indestructible in there. How can you test this?

My temperature gauge is also out. Can these burn out? Any source on a good electric replacement?

Thank you!
 
Randall will be along shortly with better answers than mine.

As you said, a direct reading ammeter is pretty simple inside. You can disconnect the wires going to the ammeter and use a multimeter set to measure ohms across the ammeter terminals. (Disconnect the wires AFTER you have disconnected the battery). You should find fairly low resistance but not an open circuit across the ammeter terminals. On the bench you can place something like a large 12V lamp in series with the wiring to/from the gauge and connect it to the cars battery. That will allow you to observe if the needle deflects when current is flowing. You'll need a big lamp... or you can use something like a spare ventilation fan or similar that draws more current. I am sure there are ways to check the gauge while it is installed but I am not versed on in-situ ammeter test methods.

The capillary tube type mechanical temperature gauges can and do fail. If the failure is not caused by handling during removal and installation, it can be from fatigue of the capillary tube or a bad solder joint anywhere in the system. You can have them professionally rebuilt or you can try the DIY method first. I have used the method in the web article linked below to repair a half-dozen or so temperature gauges. It works well. However, I suggest you use dry-ice for the cold bath instead of the salt/water bath described in the link. Dry ice is colder and cleaner.
https://www.ply33.com/Repair/tempgauge

I don't know of an electric gauge that will have the same appearance as what you are looking for. Others may have suggestions.
 
If you do want to go electric, an early TR4 gauge looks almost identical except it goes to 250°F instead of 230°F. You'll also need the appropriate sender and a voltage stabilizer/regulator to supply the 10VDC that the gauge needs to operate properly.
 
Back
Top