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MG TD TF 1500 - '52TD Electrical Problem
|I just had one of those 'wish I hadn't done that' moments. Brief story and then the problem. Just purchased '52 TD. Fairly good shape. Brakes were virtually non-existent but after adjusting and bleeding the system, could actually be safely driven. With that in mind, I was getting the car ready for driving to the car club meeting, and since it is now getting dark in evenings, I noted that there were no dash lights. I pulled out the instrument panel to put in a new bulb, which was done without difficulty. However, in putting the panel back in, I had to reach under and hold the nut for the screw to put the panel in place. In so doing, one of the wires in the instrument panel cluster 'shorted', melting two wires. When I actually crawled under and looked, there are a number of loose wires just dangling. To make matters worse, All of this wiring from the harness to the instrument panel has been replaced, for the most part with the same red wire, with only one or two marked.The two wires that were 'melted' were: One that came out of the top of the ignition/light switch; the other was dangling in instrument panel cluster. I disconnected the battery when the smoke started (which I guess I should have done earlier--live and learn, but who would have guessed). I went in today to try to replace and reconnect, and was unsuccessful. I have only a horn (which I now don't need since I can't move the car). The battery shows fully charged and as I mentioned, the horn works. The starter, lights, tail lights, and side lights which were working, are now non-operational. I would appreciate any suggestions to help me get the electrical up and going again. All because of a bulb change.|
Thanks for your help.
|...assume you checked the fuse's? |
Also assume there would be a fair amount of electrical tape under there...you might follow the burned wires to under the tape and see if something is melted under there?
Replacing the whole harness although seems daunting, is not a horrendous job (that said, I have seen it done a few times, but haven't attempted it myself)....
A friend had a TD that had 'every' single wire replaced with brown lamp wire....not a fun situation....
|I have done the complete wiring harness replacement, it went extremely well. You can get just the "sub-harness" for the instrument panel, if that's the main problem. I did not get the Moss harness, I think mine came from British Wiring, in PA. Talked with them on the fone at least once. My job is at http://www.boatanchors.org/mgtf.htm |
you can see the panel wiring about half way down the page. The TD would be a bit different. I had a 52 TD in 1962 - 70 something.
|A W Parker|
|There are pretty good pictures on my website of the dash wiring. Arm yourself with a wiring diagram and follow the circuits.|
I never remove the instrument panel on a TD. Instead, I pull the steering wheel and then the eight or so screws for the whole dash board and work with it that way.
Yes, the fuses were OK. There was a lot of tape---both electrical and and masking tape. Some tape for no apparent reason. I took it all down and there are no direct shorts. Thanks for your input.
|Bad ground? If you have the original pull cable starter switch, it should still turn over even with no wiring harness. The lights are not fused, but the horns are, not sure why they are working. Check the ground side battery cable and where it bolts to the firewall. There should be a ground strap cable between the tub/chassis mount tower at the left side by the clutch linkage with the other end going to a bellhousing bolt. Otherwise, do you have, and know how to use a wiring diagram and VOM? George|
Where are you in Virginia. I'm in Williamsburg and if you are close I can maybe help you out.
Ground seems to be OK and was working fine till I did this. I have a wiring diagram. The wiring diagram I can follow, but it's a little difficult to follow the actual wires with all the red wires back there
I am in Rockville (just outside Richmonds West End). My email is firstname.lastname@example.org. Any suggestions would be appreciated. Onlly 'hot' wire I've been able to find is a blue (one of the few non-red wires) going to the horn, but I haven't checked all. Also, I should be getting tomorrow a dashboard sub harness. I figured since it was such a mess back there I may as well start from scratch.
|Chuck, I have a diagram in front of me. If you have the separate from the regulator fuse box and 5 post regulator, the hot side of the starter switch has two separate feeds. One goes to the horns only (that one is obviously fine, since your horns work), the other powers everything else that does not work. That part of the circuit is the problem. You need a volt meter, or a 12V "stick tester" light. Trace the voltage with meter or light. Follow the juice as follows: It should be hot at the starter switch ( the side connected to the battery), next go to the ammeter- both sides should be hot. If only one side is hot and the wires are tight and connected, the ammeter is fried. Then go to terminal A on the voltage regulator (look at the cover for the schematic, think it is the second from the inside terminal) and check there. Next back to the dash, check the A terminal on the back of the light/ignition switch. Somewhere along here, the current will stop and you will find the problem. Example: if you have current at the A terminal of the regulator, and not anywhere on the light/starter switch, that wire is melted. Hope that makes sense.|
Great idea. I had not noticed that on the wiring diagram, but I was actually tracing back the other way so it wasn't an area that I noticed. I wlll check that today. I greatly appreciate the input!!
This thread was discussed between 01/10/2012 and 04/10/2012
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