TR2/3/3A TR3A Electrical Quirks, Flasher, Wipers and Fuel Guage

[GlennC]

Armed with a forum suggested wiring diagram I succeeded in rewiring my 59 TR3A, or I thought so.... I have traced all wires, checked continuity and grounds, installed a new flasher and tested all lights independently. I was tipped off that the wiring between flasher and wiper motor must be correct and I have more than triple checked that. Upon my test drive I found that my fuel guage stopped working, and my directionals do not flash. The wiper motor still works. I have blown several fuses during this endeavor as well. Has anyone else experienced this or is there a way I can pinpoint the problem?

 

[Kleykamp]

I'm no expert...especially on electrical gremlins ,but have installed 3 wiring harnesses in TR3's that worked. Just guessing from experiences I had. Do you have the separate ground wire to the fuel sending unit? On the signals, use a test light to check the terminals at the flasher unit. I ended up buying 3 flasher units before I got one that worked, but I think the first one was because I hooked it up wrong and burned it out. If you're blowing fuses, something is grounding out. Good luck.

 

[sp53]

I think you have 2 problems going on. First the 3 green wires for the flasher have different colored strips, and the wiper-- I think --steels power or ground from the fuel gauge. Are you still positive ground?

 

[TexasKnucklehead]

...also no expert, but I assume you are blowing the fuse to the green wires (because the other fuse is for the horn). The wiper should be considered separately from the turn signals. If you look at the fuse box, you should see several green wires on one side. By removing them one at a time, you should be able to determine which one (or ones) is causing the fuse to blow. Then, armed with an ohm meter, you can determine which circuit is causing the the fuse to blow. And eventually, what exactly is causing the fuse to blow. The tiniest piece of frayed wire can short out a circuit and cause the fuse to blow.

Good luck.

 

[TR3driver]

A link to which diagram you used might be helpful, along with what does happen. Ie does the gauge read full or empty; do the turn signals stay on, stay off or glow dimly; etc.

Since you don't currently have a blown fuse (it seems), I suggest focusing on the other problems for now. If the fuse blows again, you can start troubleshooting that problem.

If you wired the gauge backwards at first, it may be burnt out by now; it does not like having battery voltage applied to the 'Tank' terminal. Since it's tough to access the gauge with it installed in the panel, my suggestion is to take it loose and let it dangle on the wires, then connect a temporary ground to the mounting post. Now you can turn the key on and check for power between the 'B' terminal and the gauge housing. You should see close to battery voltage (12 volts). Check to see what the gauge needle does (being careful not to let the terminals touch the gauge panel). Turn the key off, remove the 'Tank' wire, and check again. If you don't get a (past) full indication with the Tank wire off and 12v applied, the gauge is bad.

I've had a lot of trouble in the past with new flashers that did not work properly when used in a TR3. It seems that the flasher manufacturers have a different idea of how the circuit should be wired. So, I suggest temporarily connecting a jumper between the green and green/brown wires at the flasher, then checking that all 4 corner lamps come on as they should. Try it first with the parking lamps off, then again with the parking lamps on to check that the turn filament is much brighter than the parking (aka marker aka tail) filament (and that it still works with the parking filament on). If not, then there is a problem with the wiring, switch or lamps.

You can also temporarily connect a jumper from the green wire to the light green wire (or whatever color it actually is in your harness) and check that the yellow (or green) dash indicator now comes on whenever the key is on. If not, there is a problem in the wiring to the lamp, or the lamp itself.

If all these work, I would try another flasher, maybe the old one you took out. Or see if your FLAPS has a Tridon EL13 flasher in stock, as they seem to work well. (At one time, I went through every other 3-terminal flasher my FLAPS had in stock, the EL 13 was the only one that actually worked.)