engine and drivetrain Reverse (manual) blows fuse 12

[dietz520]

I have a '72 manual transmission Tii. It started shorting fuse 12 very frequently. My hazards were not working and I had poked around behind the stereo and the problem got worse after that, so I just assumed I had done something and went at it again. Now my hazards are working (just a loose connection) and I have narrowed the short down to when I put the car in reverse. I went through all the connections in the tail lights, but it is still shorting. I am 99% sure that it the reverse that is doing it, but can't find the damn short. Anybody have good tactics? I will say this... the passenger side reverse light wasn't working (when things were working) despite an OK bulb, which is suspicious, and on that side, on the tail light assembly, there is some random lamp cord coming to the ground... or what I think is the ground, as it is the only connection not going directly to a bulb socket, it is kind of tucked in a nook.

Any direction would be greatly appreciated. Not having hazards was annoying. Not having rear lights of any kind, blinkers, or a horn, in Brooklyn, is not OK- it's getting cold and people have their windows up, so I can't yell loud enough.

Thanks

A

[BillWilliams]

The reverse light switch on the five speed is on the top and near the front of the transmission. In good light, you can look through the engine bay towards the top of the transmission and see the switch,

Two wires run down the tranny tunnel to the rear of the car, somewhere along the run, one of the wires picks up power, (it is spliced into a switched hot wire) then the wires continue on to the trunk area.

Usually the wires get pinched on top of the tranny near the rear of the tranny.

Take a look at your wires and see if you can see a pinch, new wires are easy to run if needed.

[dietz520]

Awesome, I'll check it out. Where, roughly, does the tranny end? It is not as far back as the rear wheels is it? I only ask because a) I am somewhat of a rookie,and I just put a new exhaust shock on the exhaust pipe on the bracket kind of right behind the rear axle, right behind what looks similar to a transmission housing, but could be the drive train. I only ask because that muffler was bouncing and rattling like crazy and could have definitely pinched anything in its path, and would coincide well with the timing of the problem.

[Inka114]

The trans reaches back to just in front of your shifter. Once you get the car on jackstands, and you can climb underneath, you'll see the driveshaft and shifter attached to the back of the trans, just about where the front of the front seats are.

The housing you saw out back is your differential, where the back end of the driveshaft attaches, and the halfshafts come out the sides to drive the rear wheels.

Good luck!

[BillWilliams]

You can see the switch in this photo. It is the round thing sicking up on the top with two male spade tips on it.

[dietz520]

That's amazing... I doubt mine will look exactly like that. Are you eating lunch off of that transmission in that picture?

[MatthewCervi]

Bill does very nice work on his cars. You definitely want to check them out if you ever get a chance.

BTW, do you have a 5-speed or a 4-speed transmission? The switch on the stock 4-speed is on the back of the transmission.

[jan1968]

You can see the switch in this photo. It is the round thing sicking up on the top with two male spade tips on it.

While were on the subject of transmission. What's that right next to the switch at 8 o'clock that looks like a nail head (couldn't come up with a better description) ? In mine it's installed flush to the bell housing and I can turn it.

Also, where does the transmission oil go in or for that matter where do you drain it ?

Thanks,

jan

[jan1968]

You can see the switch in this photo. It is the round thing sicking up on the top with two male spade tips on it.

While were on the subject of transmission. What's that right next to the switch at 8 o'clock that looks like a nail head (couldn't come up with a better description) ? In mine it's installed flush to the bell housing and I can turn it.

Also, where does the transmission oil go in or for that matter where do you drain it ?

Thanks,

jan

[BillWilliams]

The nail head looking thing is the breather cap. Turn the tranny over and oil will leak out.

The fill hole is on the other side, it takes a17mm (I think) reverse hex head tool (a VW special tool if you get one from one of the tool trucks) to take it loose or weld up some nuts to a bolt and it will work also,

The drain is on the bottom, apparent I think. Always remember to remove the fill plug before you ever drain the tranny. Why, you want to ensure you can fill it if you drain it.

[MatthewCervi]

The round cap near the reverse switch in the picture is the vent.

I don't know where the filler plug is on the 5-speed. On the 4-speed it is on the left side, roughly in the lower middle. The drain is on the bottom...and of course always open the filler hole before the drain or you could be in big trouble if the filler bolt is frozen!

[BillWilliams]

Fill plug on a five speed

Special tool to remove fill plug

[jgerock]

You can also use the (as Bill mentioned) 17mm allen wrench thats the same as the VW air-cooled transaxle.

Make sure the breather vent isn't plugged or else you could blow gear oil out the rear (like mine did). I used a piece of s/s picture hanging wire to push into the breather. I bought a new vent for future use.

4-speed reverse light is on tailshaft - I ziptied my wires to the brake line to keep them away from the driveshaft.