The Official Auto-to-Manual Transmission Swap Thread

[auto3251]

Just a thought....but maybe YOU should buy a bentley manual and stop assuming that the members of these forums owe you something...Sorry if it wasn't described step by step for you, but keep in mind it wasn't described step by step for any1 else either. If you have a question about a wiring problem with your swap,then ask away, but don't bash everyone for not making your life easier for you. My message to you here is your screen name as viewed from a mirror!
Have a nice day and good luck with your wiring woes

Dude, he was just trying to help some people out. So many other people in this thread, and outside this thread has asked about the wiring, and it would be in best intrest to have a little write up on it. He was suggesting "maybe" and finished off with "just a thought." No eyerolling or dumbass comments.

And I would have to agree with him, when ever someone ask about the wiring, people just slap this thread at them. As someone who has also read through this thread, I did not see anything helpful. And I think the information on the reverse switch here so far is wrong. I got "rewire a switch onto the shifter to the manual transmission"

[auto3251]

From the center console, I'll route the proper wiring to the reverse light switch and get that working as well. I'll take photos of all of this along the way and post them for the world to see.

MrMonte.

Please do, so many people is left in the rain about this. To clear things up for now, what wires are the reverse light switch? And you wired it to the manual transmission correct?

[al_r]

Auto325i - are you saying my reverse wiring switch setup (in the M3 forum) is wrong? What did you to yours? Maybe different year/wire colors?
My cruise and backup lights work - I did what I wrote about and have gotten a few PMs saying thanks for the info cuz theirs works too.

I'm not pointing fingers at anyone here, I'm trying to help...

[auto3251]

Crap, how did I mess that?

Here it goes:

Reverse Light Fix

"The backup light switch closes when in reverse. On my car, Grn/Wht is +12, Blu/Yel is out to the lights. These used to go to pins 2 & 3 of the Auto switch contraption." -a lr

"- Someone also asked about the reverse light switch - originally controlled by the auto shift lever; those same two wires now need to get routed to the backup light switch on the right side of the 5-speed. Hardest part is getting the wires from the area under the OBC throught the floor. I strung mine through an existing hole in the passenger firewall into the engine compartment and down/back from there." -a lr

[CrazedBMW]

Crap, how did I mess that?

Here it goes:

Reverse Light Fix

"The backup light switch closes when in reverse. On my car, Grn/Wht is +12, Blu/Yel is out to the lights. These used to go to pins 2 & 3 of the Auto switch contraption." -a lr

"- Someone also asked about the reverse light switch - originally controlled by the auto shift lever; those same two wires now need to get routed to the backup light switch on the right side of the 5-speed. Hardest part is getting the wires from the area under the OBC throught the floor. I strung mine through an existing hole in the passenger firewall into the engine compartment and down/back from there." -a lr

I was told by a mechanic not to use the existing auto reverse light plug in (the part that plugs into the tranny) I bought a new one fora 5 speed and I never had any problems. It's also way easier because you don't have to RE-WIRE, you can just WIRE. I'm not sure if your Reverse lights work yet, lemme know if they don't and I can give you my setup.

[str8 gone]

Dude, he was just trying to help some people out. So many other people in this thread, and outside this thread has asked about the wiring, and it would be in best intrest to have a little write up on it. He was suggesting "maybe" and finished off with "just a thought." No eyerolling or dumbass comments.

And I would have to agree with him, when ever someone ask about the wiring, people just slap this thread at them. As someone who has also read through this thread, I did not see anything helpful. And I think the information on the reverse switch here so far is wrong. I got "rewire a switch onto the shifter to the manual transmission"

Understood,but the info found here should be used as a guideline and not as gospel.What works for one model year may not with another.Point is, if you don't understand wiring or possess a shop manual with wiring diagrams of YOUR vehicle,you cannot expect to accomplish this without troubles.Refer to the bentley for your car,find the reverse light wiring(there are only two of em,your specific colors may vary),disconnect them from the old auto selector harness,and connect them to the 5 spd reverse switch located on the side of the trans.....done deal

[99mcab]

my mechanic is doing the swap for me. its a 99 M3. he finished everything and went to start it and it started then shut off after 2 sec. the car starts but shuts off after 2 sec. what is the problem? is it the clearing of the computer? (not sure if he did that) also, my key is new, someone told me there is a trick taht you do to program the key to your computer? (not sure if that is true) what can it be? its starts then shuts off after 2 sec. is it some sort of anti-theft?
please help
thanks

[Mrmontecristo]

I jusr finished the wiring for the cruise control and the reverse lights. It took some planing and some investigation, and tearing open the center console, but it was fairly straight forward from there. I'll post my pics and a write up on this tomorrow. A side note to all of this. When I opened the center console and found the wiring plug that used to go into the auto range switch for the old auto tranny , I found wires 5 and 7 just jumpered. This would have allowed the cruise to work, and also explained why I was able to start my car without the clutch engaged as a fail safe. I even asked my mechanic why the car would start without the clutch engaged which again, is a safety feature, just like having an auto trans car in park or neutral. His explaination was, "oh that didn't take effect until later model years". Lying sack of S&$t!
Now with the relay in place, I have to engage the clutch to start the car, and also having the clutch engaged defeats the cruise control just like OE. Yea, I could have used a brake light switch, as suggested here by someone, but I called the $tlealer and he wanted $50.00 for it vs. $3.50 for the relay from radio shack. I bit more ghetto, but at the end of the day, it works...More to follow....
Road trip to Anza Borrego dessert tomorrow to check out this year's crop of dessert wild flowers after our record rainfall. Can wait to use that cruise control on Hwy78!
Mr. Monte

[auto3251]

I jusr finished the wiring for the cruise control and the reverse lights. It took some planing and some investigation, and tearing open the center console, but it was fairly straight forward from there. I'll post my pics and a write up on this tomorrow. A side note to all of this. When I opened the center console and found the wiring plug that used to go into the auto range switch for the old auto tranny , I found wires 5 and 7 just jumpered. This would have allowed the cruise to work, and also explained why I was able to start my car without the clutch engaged as a fail safe. I even asked my mechanic why the car would start without the clutch engaged which again, is a safety feature, just like having an auto trans car in park or neutral. His explaination was, "oh that didn't take effect until later model years". Lying sack of S&$t!
Now with the relay in place, I have to engage the clutch to start the car, and also having the clutch engaged defeats the cruise control just like OE. Yea, I could have used a brake light switch, as suggested here by someone, but I called the $tlealer and he wanted $50.00 for it vs. $3.50 for the relay from radio shack. I bit more ghetto, but at the end of the day, it works...More to follow....
Road trip to Anza Borrego dessert tomorrow to check out this year's crop of dessert wild flowers after our record rainfall. Can wait to use that cruise control on Hwy78!
Mr. Monte

I don't get it, what exactly did you do? I would guess you still need a switch on your clutch pedal to get it working witha relay.

[SecretAznSauce]

Did no one read my post on just hooking the park/nuetral wire to the blk/yel ingiton wire? it provides 12vdc while cranking any never else therefore you are never excercising that big yellow AT relay everytime you push your clutch in.


thats what fixed my problem

[Mrmontecristo]

Did no one read my post on just hooking the park/nuetral wire to the blk/yel ingiton wire? it provides 12vdc while cranking any never else therefore you are never excercising that big yellow AT relay everytime you push your clutch in.


thats what fixed my problem

SecretAznMan4u - yes, I read and I'm sure everyone else did also, your fix. I'm happy to see that it works for you. This is just a more conservative approach to what I was looking to accomplish:
I was trying to accomplish three things:
1. Re-enable the OE clutch engaged to start the car
2. Re-enable car in gear permissive for cruise control operation
3. re-enable cruise control disengage when clutch is depressed.
Using a brake switch in place of the clutch switch instead of wiring up the relay through the clutch switch would accomplish all three, but again the brake switch was $45.00 more than the relay. Got the pics here with me @ work, so I'll work on the DIY today and hopefully post it this afternoon.

[SecretAznSauce]

SecretAznMan4u - yes, I read and I'm sure everyone else did also, your fix. I'm happy to see that it works for you. This is just a more conservative approach to what I was looking to accomplish:
I was trying to accomplish three things:
1. Re-enable the OE clutch engaged to start the car
2. Re-enable car in gear permissive for cruise control operation
3. re-enable cruise control disengage when clutch is depressed.
Using a brake switch in place of the clutch switch instead of wiring up the relay through the clutch switch would accomplish all three, but again the brake switch was $45.00 more than the relay. Got the pics here with me @ work, so I'll work on the DIY today and hopefully post it this afternoon.

I originally came up with the brake switch thingy, but changed it, because I noticed that everytime you step on brake or clutch you will energize the AT relay. that relay is not cheap to replace. in a normal drive to work, i counted over 65 brake times, prob. more for clutching. Your mechanic is right. the early year bmws did not come with a switch on the clutch to start the car. You could start the car withput pressing the clutch. but 'm used to doing it any ways. Also you will notice with the clutch or brake switch mod you will notice RPM dropping while the pedal is engage, as mentioned \by boosted318. I experienced the same problem. With this new method of wiring to the starter wire, I no longer energize the relay unless the car is being started

[Mrmontecristo]

The AT relay you are talking about, do you mean the starter relay coil? Looking through the Bentley electrical starter drawing (pg 64 for my '94) I see where if you run blk/ylw wire (#4) from the start switch to wire #7 of the auto range circuit, it'll make up the starter coil, seal in the contacts on the starter relay and start the car. I can see where using my clutch switch in place of the blk/ylw wire will energize this coil every time the clutch is engaged although no voltage will be traveling through the contacts since the start switch is now de-energized. So now my questions/comments are:
1. How can you disable the cruise while it's in use if you push in the clutch pedal? Obvious answer is don't push in the pedal while the cruise is in use, but I'm looking for something a little more fail safe than that. I'll look for a way to do this.
2. You (and my mechanic) are right. The is nothing in the Bentley about there being a circuit in the clutch which disables the starter. It only refers to the auto range switch on an AT. My mechanic is still fired though!
3. Still looking for a way to disable the starter unless the clutch depressed.
Maybe a simple switch located inside the car which would disable my current wiring after starting, and then place it back in service when I'm using the cruise.
What do you think?
By the way, thanks for getting me thinking more about this
MrMonte

[Boosted318is]

I still have not got an answer to why the engine RPM varies as the clutch is activated with the relay fix implimented. I really enjoy the functionality of having the clutch pedal disable/enable the cruise and enable the starter. Unfortunately I still get the small and annoying idle fluctuations when I excercise the clutch in and out at idle.

It would be great if someone could give up some details on why the engine rpms vary and also if this can be remedied with an EROM coded for a manual. This is the information I cannot seem to find in the Bentley.

[SecretAznSauce]

well thats simple. the cruise is already disengage by the brake pedal. who here pushes the clutch instead of the brake to turn of the cruise? as far as starting the car only with with the clutch depressed?thats easy. use a 5 prone relay. when clutch is pressed the switch creates an open that tells the relay to close hince closing the wire that goes to the p/n wire to starter blk/yel wire. when the cluth is up, the relay opens, and the circuit is killed

[Mrmontecristo]

Yea, I see your point on the brake/clutch issue and disengaging the cruise. I work in a power plant and I'm kind of trained to expect the unexpected. Say for instance, you're cruising along I-5 with cruise control engaged and decide the downshift while going over the grapevine, forgetting you're in cruise. Do you think there's a chance that you could over rev your engine instantly after engaging the clutch? I'm not sure as I've never dynamically tested this theory... By the way, how's this whole thing wired with a car that comes factory with a manual tranny and cruise? I didn't even think about that....
Good conversation though! I like all the input and hopefully in the end we'll figure out a scheme that satisfies everyone's issues. BF.com rocks!

[al_r]

who here pushes the clutch instead of the brake to turn of the cruise?

I push the clutch instead of telling the cop behind me I'm on the brakes...

[Boosted318is]

I push the clutch instead of telling the cop behind me I'm on the brakes...

That is actually a good point.

[SecretAznSauce]

I push the clutch instead of telling the cop behind me I'm on the brakes...

hmm. i used the button control, i'm used to my 93 not even having a clutch switch

[Boosted318is]

well thats simple. the cruise is already disengage by the brake pedal. who here pushes the clutch instead of the brake to turn of the cruise? as far as starting the car only with with the clutch depressed?thats easy. use a 5 prone relay. when clutch is pressed the switch creates an open that tells the relay to close hince closing the wire that goes to the p/n wire to starter blk/yel wire. when the cluth is up, the relay opens, and the circuit is killed

Great info. You are really getting us all to think more about this situation. Any thoughts on what is actually causing the idle droop we talked about? I understand it is an open/closed circuit issue, but how does the circuit function??

[al_r]

Both of my earlier E36s ('92 & '94), sticks from the factory, had a clutch switch that would disengage the cruise. Dunno if they also did the starter interlock, since that's so ingrained (in me) to depress the clutch, then turn the key to start...

[Mrmontecristo]

On a less technical note, I did manage to get my reverse lights hooked up which was REALLY simple. I just jacked up the car, checked the continuity at the reverse switch plug just to make sure it worked (located on the left side of a getrag tranny). Then from the auto range switch plug I cut the GRN/WHT and BLU/YEL wires and spliced them onto two lengths of 20 gauge wire (about 2 feet to be conservative). I threaded the wires through one of the holes that the auto range switch used to attach to (currently viewable underneath your shift boot). I then connected the two wires into the reverse switch plug and voila! reverse lights. Attached are photos of the wires going through the hole, the auto range switch plug with wires cut (for both the cruise control mod and the rev lights hook up), and my gutted center console before clean up.

[auto3251]

What the heck?
After the swap, will I have a rev. limiter just like manual? I did the swap, with still the 3.91 in there, first gear is very fast. Floored it from a stop it and it went striaght into redline and hit 7k rpm before I notice and took my foot off the gas. What the heck!?!?!
Is there no rev limiter with the auto ecu since the auto computer shifts for you?

I did it twice so far, how bad is this for my car guys? Almost crapped in my pants when I saw it hit 7k. redline is 6,300 for me, it went striaght pass all the redlines into the solid red and up to 7k!!!

Oh yeah, stock ecu and chip.

[Mrmontecristo]

With your swap, the auto computer is no longer in the mix, although I don't believe it contolled your rpm limit before. With that 3.91, it's almost like you're cruising down the road in any gear and do a money shift. You're gonnna sail past your limiter on the way to engine damage. In 1st, the gearing is so short, it just jumps up before the rev limiter can catch up IMHO.
I got rid of my 3.91 and went down to a 3.15. It's very conservative, but then again my car has 184K miles on it, and I wanted to enjoy it for awhile longer before revving it into the ground. Maybe look at a 3.23 or a 3.46? This would be a happy medium for you. With the 3.91, you''ll be spinning 3800 rpm at 70mph and 4200 at 80rpm. If you're not a freeway driver this isn't a problem, but if you are, it'll a lot of high revs for your baby. Just depends on your situation.
By the way, isn't your car with a manual tranny like driving a new car? I couldn't believe the difference when I did my swap! Awesome!

[auto3251]

With your swap, the auto computer is no longer in the mix, although I don't believe it contolled your rpm limit before. With that 3.91, it's almost like you're cruising down the road in any gear and do a money shift. You're gonnna sail past your limiter on the way to engine damage. In 1st, the gearing is so short, it just jumps up before the rev limiter can catch up IMHO.
I got rid of my 3.91 and went down to a 3.15. It's very conservative, but then again my car has 184K miles on it, and I wanted to enjoy it for awhile longer before revving it into the ground. Maybe look at a 3.23 or a 3.46? This would be a happy medium for you. With the 3.91, you''ll be spinning 3800 rpm at 70mph and 4200 at 80rpm. If you're not a freeway driver this isn't a problem, but if you are, it'll a lot of high revs for your baby. Just depends on your situation.
By the way, isn't your car with a manual tranny like driving a new car? I couldn't believe the difference when I did my swap! Awesome!

How bad did that hurt my engine? I saw it reach 7k and bounch back down yesterday. almost crapped in my pants seeing how fast it shot up.
Car still feels the same to me, but a lot of times, I leave it in first gear, wake up in the morning, and turn on the car forgetting I have a manual. D'oh! Sounds so nasty starting the car with still in 1st!