TR2 & TR3 Forum

I went behind the dashboard panel to tidy up but accidentally caused a problem while I was back there.

The fuse that shuts off the turn indicators/brake lights/fuel gauge... maybe other things is now blowing as soon as I turn the ignition switch on.

Now, I figured it had to do with the fuel gauge wiring and I pulled the panel back off and found a stray wire that I probably pulled off accidentally while I was back there.

The only trouble is the wiring diagram I have is not useful and does not seem to know about this wire.

Can anyone help?

Here is a photo.

Graham,

Hard to tell the color of the offending wire. Looks to me to be green/purple which is for brake lights except that color does not go to the center dash wire harness. If it is solid green then that would be coming from the fusebox A4 terminal. Best to take a few better pics so that it can be properly identified.

---

Barry
59 TR3A 0TS57675LO - "Loose Wheels" Frame off Restoration 1995 Owned 1994- present
76 TR6 CF54266U - "The Tweetster" Frame off Restoration 2012 Owned 2012 - present
77 MGB Owned 1993- about 2015 R.I.P. Don't ask about the untimely demise of this one
76 TR7 Purchased new in 1976, Owned 1976-1979 Worst car I ever owned from a reliability point of view but when it drove it was terrific
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)

Hi Graham,

Looks like the loose wire is hooked to the green wire connection on the fuel gauge, so it will be 'hot' whenever the ignition is on. If it grounds out (easy to do in the crowded wiring back there) the fuse will blow. On early cars (TR2/3) the wiper switch got power from that connection, although the wiring diagram shows it was a green wire. A TR3A/B wiring harness shouldn't have that connection; the self-parking wiper motors got power from a dedicated green wire from the fusebox, and the dash switch provided a ground vice power.

I checked my car and no extra wire there. Pull that wire off and see if the wipers still work. In the past, someone may have used it to provide power to something, but its too short to go anywhere but a panel switch...of which there's not many.

Jeff

Thanks for the input

I'll look into it further today.

Big weekend for the 3

First drive in over 20 years and probably put about 50 miles on it.

This is just where I happened to end up at the end of the day yesterday.



Edited 1 time(s). Last edit at 2023-08-14 05:24 AM by risingsunexperience.

As mentioned above, that wire will be live once the ignition is turned on - hence your short as it brushes against some piece of metal. In my opinion, the most likely scenario is that it ran to the heating fan.

I thought about that. I'll look into it this evening. Thanks

OK so someone was taking power from the fuel gauge and using it on the wiper switch apparently.

It was the only thing within the wires reach.

I can't tell from the photo which wire you are talking about.

A wiring diagram is attached.

The fuel gauge should have a green wire to one terminal and a green/ black wire to the other terminal.

I think there is supposed to be a "black" wire from the center knurled nut post bracket to a ground but I'm not sure. Such a black ground wire is not shown on the wiring diagram.

Roy

Graham,

Someone apparently followed the wiring diagram for the TR2 that came with a CRT motor. (See below) It is a common error if they follow the workshop manual wiring diagram. normally for a TR3B you would have a DR2 ‘'self-parking’’ motor and the switch sends body ground not power to the motor.
You will likely find a black/green wire attached on the other side of the switch. Given that you appear to have power going through the wiper switch, I'd be very surprised that if you have a DR2 motor that it runs as it should. II it runs then likely the 1 and 2 terminals are reversed, and the motor does not self-park.

---

Barry
59 TR3A 0TS57675LO - "Loose Wheels" Frame off Restoration 1995 Owned 1994- present
76 TR6 CF54266U - "The Tweetster" Frame off Restoration 2012 Owned 2012 - present
77 MGB Owned 1993- about 2015 R.I.P. Don't ask about the untimely demise of this one
76 TR7 Purchased new in 1976, Owned 1976-1979 Worst car I ever owned from a reliability point of view but when it drove it was terrific
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)



Edited 1 time(s). Last edit at 2023-08-15 01:25 PM by Jacad.

Thanks for the insight! I will check on that this evening.

Well... it's a DR2 motor. And nothing happens when I pull the switch so...

Yeah well that’s never going to work wired that way.

At the motor
1) The red wire coming out the backside of the motor that is attached to ground on the wiper gearbox should be detached and reattached to the top of the ‘’self-parking’’ switch. (The cap with the terminal connector on top)
2) the third wire to the motor appears to be cut short.
3) attach the 3 wires in the same order as in the photo I posted earlier

At the switch
1) detach the loose wire that was grounding out and throw it away.
2) attach a new black wire to the ground terminal of the dashplate and attach the other end to the wiper switch. On the other side of the switch a black/green wire should be attached.

If the motor still works you should then have wipers! If it works, loosen the 2 small hex screws near the motor holding down the gearbox cover turn the wiper switch off and see where the wipers stop. rotate the ‘’self-parking’’ switch until when you shut off the wiper switch, the wipers stop at the desired position.

---

Barry
59 TR3A 0TS57675LO - "Loose Wheels" Frame off Restoration 1995 Owned 1994- present
76 TR6 CF54266U - "The Tweetster" Frame off Restoration 2012 Owned 2012 - present
77 MGB Owned 1993- about 2015 R.I.P. Don't ask about the untimely demise of this one
76 TR7 Purchased new in 1976, Owned 1976-1979 Worst car I ever owned from a reliability point of view but when it drove it was terrific
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)



Edited 2 time(s). Last edit at 2023-08-15 03:59 PM by Jacad.

Oh great.

OK so... I'd like to follow through with this but what I would like to know now (after having the dash plate off numerous times) IS:

My car has a heater that has been bypassed so I would like to take it out and give it a good inspection, test it for leaks and solder up any cracks or holes in the heater core that I may find.

I noticed that there are 4 clips around the heat exchanger that appear to be able to be pried off... is that all there is to removing this or will I be removing the glovebox to gain access to other mounting bolts?
I know that the heaters in these cars are more of an accessory than anything else so it could be that simple.

-I've gone through the regular things to get the car road worthy I wouldn't yet consider myself TR3 "literate".

I'd really like to do this before I do any work on the backside of the dash panel again because it makes getting the wing nuts on the back a real chore!

Graham,

To test and repair the heater you would likely want to remove the complete assembly from the car.
There are 3 points that hold the heater bracket in place. At the top center is a stud the goes through the firewall above the center of the battery. Then there are 2 bolts on either side that hold it to the rails that need to be undone or just unscrew the 2 rails and then you can remove the assembly from under the dash.
Once it’s out, remove the 3 or 4 large clips that hold the top and bottom plates and then remove the fan from the motor by undoing the locking nut. Take the core to a rad shop and have them clean it out.

---

Barry
59 TR3A 0TS57675LO - "Loose Wheels" Frame off Restoration 1995 Owned 1994- present
76 TR6 CF54266U - "The Tweetster" Frame off Restoration 2012 Owned 2012 - present
77 MGB Owned 1993- about 2015 R.I.P. Don't ask about the untimely demise of this one
76 TR7 Purchased new in 1976, Owned 1976-1979 Worst car I ever owned from a reliability point of view but when it drove it was terrific
Website: Triumph TR2-TR3-TR4 www.trtriumph.com/ (sorry for not keeping it current for the past couple of years)



Edited 2 time(s). Last edit at 2023-08-15 05:45 PM by Jacad.

When removing the heater you will likely disturb some back panel wiring. You will most likely have difficulty getting the hearer hosws off the heater. Unless you cN remov3le the hoses from the engine connections and blow it any coolant from the hoses and heater before disconnecteding the hoses from the hearer, you are likely going to get coolant coming out of the heater into the car. And probably will get water inside the car regardless whether you blow out the heater or not.