Bill Ball

Gotcha. Could you clarify what the diode across the hatch relay coil leads does?

borland

That's just a diode to eliminate back-EMF current from the relay coil into neighboring circuits. Might be unnecessary. Easier to install the diode than to do back-EMF testing.

Bill Ball

Er, uh, what would be the potential effects of "back-EMF"?

shadowknight

Bill/Alan need a little assistance on this topic. I have an 89 with two pull switches for the trunk, installed is a 5900 Viper alarm. I am looking to integrate the alarm to the trunk release. The viper has a 200ma (-) output channel for the trunk. Which of the diagrams on this thread should I use?

borland

Could cause permanent damage to sensitive integrated circuits or temporary circuit glitches.

dprantl

What I did when I had to join multiple wires together during my keyless install was to crimp ring terminals to the ends of the wires, then get a very short bolt and nut and join them all together that way. Then I made sure to insulate the bolt very well. You can be sure the connections will stay good with this method.

Dan
'91 928GT S/C 475hp/460lb.ft

Alan

Bill I think the Scotchloc taps are probably the best option here - just make sure they are sized appropriatley for the stock wiring. I'd not normally recommend these but for this application there are few realistic alternatives. I do not have terminals for these alarm connectors and there is little free room or stock loom wire length to play with.

Alan

Bill Ball

There are LOTS of ways to go at the hatch. If you don't care about the door pin interlock (prevents the hatch pull from working with the doors closed), you can just cut the brown/white switched ground wire to the hatch motor and permanently ground the motor end to a nearby ground point. Then all you need is a single relay to have the ground output of the hatch/option button on the keyless entry system trigger 12V to the yellow wire on the passenger or driver side door pull. This relay would be wired 12V to pin 30 and 85, keyless's hatch ground to 86, output to yellow wire on 87. That is the simplest setup. If you want to preserve the hatch safety interlock, then you need another relay to provide ground to the hatch motor rather than grounding the hatch motor permanently. You can use a DPDT relay as Borland shows for both the power and ground. RadioShack sells them. But, as I found, the ground signal from my keyless cuts off too soon, and although the hatch pops, the hatch motor will not complete its cycle. So, I ran a jumper from the lower hatch latch receiver brown/white wire to the hatch motor brown wire, and that provides the continued ground allowing the hatch motor to cycle properly. There are may other ways to do this, but that's relatively simple.

Oops! I forgot you need to send a disarm signal to the alarm when popping the hatch.

Stromius

Many thanks to Bill, Alan, Ed and others for helping prompt someone like me to (finally) install their KE. I have an 88 S4 without factory alarm. I have followed the recommeneded installs and have gotten most wires pull and located.

HELP NEEDED: I do however have a question on the Central Locking Control and which wires to go after there for lock/unlock. in my 88, there are 8 posts in the CL unit. Note in pic, 2 yellow wires so 9 total.

Below are the CL pics (2) and my progress so far with the KE (1) which is going into the passenger amp cover. Because the amp is long gone, I am using ground (brown) and constant +ve (red with 15 amp fuse at CE) and have located ignition at Q15, side markers at S24, S23 (each with 6A diodes).

For the hatch, I am using 2 relays as suggested by Bill/Alan in conjunction with a 1A diode to the yellow hatch pull and new wire to back with another 1A diode, to retain factory function and a little less obtrusive and removable without too much hassle.

Thanks in advance for help on locating the correct wires in the CL unit.

EDIT: Search became my friend. Alan 88 setup had the colors right there looks like post 3(YELLOW - LOCK) and post 5 (GREEN/BLACK - Unlock) where post 1 is bottom left (blue/red). I plan to solder onto the post.

uncre8tv

Trying to install an eBay cheap KE box in my '89 S4. ONLY trying to get locks and lights, no hatch no horn no alarm (no alarm box in mine... that I see...)

In the AC/Central Lock/0-reset unit I've got six wires coming off - yellow for +12v, brown for ground, then a dull rainbow for the other four which does not include gr/blk (and I've already established the yellow is +12v).

This diagram gives me hope that I might be able to do what I want by tapping into these wires. But playing with the mm and some jumpers I'm not so sure. (also that Central Lock button is lock-only when the key is out, right?)

I know there are tons of KE threads, but all of them are a little different in execution and the color codes are generally not reflective of my '89. So any additional (and likely redundant, apologies again) pointers would be appreciated.

Alan

You can't connect there - you need the central locking module & the alarm module - if you have one (I'd think you would likely have one in an '89).

Alan

uncre8tv

Thanks for the reply, Alan. Clues on ID'ing the Central Lock module? Should it be in the pile of modules behind the console, or I've seen some references to under the passenger seat?

EDIT - nevermind I just saw Stefan's pics (was jostling around in the thread) so I'll continue my search! thanks!

x98boardwell

I was searching as to why my key fob wasn't working and came across this thread. Can someone confirm that all related items for the keyless entry are under the passenger seat?

After installing a newer style Boxster radio the doors stopped locking so I was curious as to what in that area controls the door locking system but wasn't sure.

This is for a 94' GTS and I've included pics of the key fob below. Appears as though this was installed many years ago. Battery in both key fobs are good!

Thanks for any help on wiring potential behind radio... maybe based on my key fobs. I will remove passenger panel by factory amp but car is on a lift for storage right now so won't have time until next week sometime.

Happy Turkey Day!
Bryan

Kevin in Atlanta

I'd start by making sure the connectors at the back of the ! button panel are still connected.

Bill Ball

Yes, if you refer to the diagram above (post 158) for 91-95 in this thread, the Alarm unit that is the main interface is under the passenger seat. It's possible you disturbed a power or ground source to the remote control aftermarket box when installing the radio. Find the remote box and trace its power and ground wires as well as the interface with the 928 alarm unit under the seat.