Need help bypassing H and P immobiliser 1990 C4

[Johnny G Pipe]

Hi folks, my good ol 964 has only let me down once in 20 years - until last week. Stranded with a non-start issue and recovered thankfully the 10 miles back home.

I think it is immobiliser related - like most UK 964s of this vintage I have the PA1000 fitted by Hamilton and Palmer, mine has the fob with buttons, not the stick. Its a newish fob and I already tried my spare battery.

But I think the problem is the immobiliser unit. Normally a few seconds after unlock or after turning off the motor I get 3(?) beeps and a click, which is the immobiliser auto-arming. A central LED flashes...It has stopped doing any of that.

When I try to start, everything lights up with brake pressure pump whirring etc when I turn the key, but no cranking. It would not bump start either (I was on a hill) so no fuel getting through.

So in other words no starter and no fuel, plus the lack of normal beeps strongly suggests immobiliser.

The car has a new starter and the recovery guy also tried powering up with external 12v - no change.

I have contacted H and P, and their technician Jim who knows these systems has just retired and they are no longer supplying parts. So we are on our own now! The US forums are a little confusing because their cars have a different set up, but I know there are a few UK guys who would also like to know how to get rid of their H and P immobilisers so they don't get stranded on their next big trip..and so I thought I would try here and 911UK.

The car is stuck in the garage and so I am hoping someone can tell me which wire to connect to which..I am not very good with circuit diagrams. I have ID'd the Immobiliser box under the seat, will need special anti tamper tools to unbolt it..Thanks for any advice.

Edited by Johnny G Pipe on Saturday 1st October 11:17

[Fnumber1user]

Even if 20 years old the wiring will most likely be all black on the H&P - my advice would be to get a qualified auto electrician in to remove and replace with new alternative.

Immobilising the fuel pump and starter circuits are/were the most popular, hence why bumping it wouldn't work = no fuel = no run.

[Johnny G Pipe]

Hi, thanks, yes the wiring is indeed all black. They weren’t messing about!
Its looking increasing likely its going to need flatbedded to someone who knows what they are doing. Both of these will be a challenge in my experience. Hey ho.

[ChrisDT]

Depending on where you are in the world they sill exist https://www.hamilton-palmer.co.uk/

[FarQue]

ChrisDT said:

Depending on where you are in the world they sill exist https://www.hamilton-palmer.co.uk/

Did the OP not suggest a current lack of technical support in his post?

[Wozy68]

I’m surprised you have any beeps etc plus also a fob.

I have a very early 993 which had a H&P immobiliser and they didn’t have a remote just a slot to put the immobile key into. Later cars had the fob.

The sunroof drain plugs became blocked in mine and the interior got soaked which made the immobiliser fail.

Called out the AA and low and behold it was flagged on their system as they had the same issue in the past and the AA guy pulled out the passenger seat and removed the H&P unit and bypassed the immobiliser key and off I went.

[Johnny G Pipe]

Top AAery that. And is what I want to do..

[Porschekiduk]

Where r u based,as there may be a long term Porsche tech with the knowledge u need.

The starter cut is easy fix,but 2nd immobiliser cut depends on how sneaky the technician was,in hiding the wiring.

Chris

[phib]

If you are anywhere near surrey I know a great guy that could probably help, does main dealer Ferrari, Porsche etc. mainly trouble shooting these days.

He took two aftermarket alarms and an old tracker out of my 355 and has done 993's for me in the past.

Phib

[Johnny G Pipe]

Thanks guys. I called a mobile auto spark in Dundee in the end, chose one with good reviews but wasn't sure how hopeful to be. He came out last weekend and had it bypassed and the car running before I could make him a cup of tea.

Which is tremendous, obviously. I have been away since then and haven't had the time to have a good look at what he did, and I'd best not share it here just in case anyway.

But he said it was pretty straightforward, which is good news for those of us with this system. My advice would be to bypass it now or have it replaced so it can't let you down.

[FarQue]

Johnny G Pipe said:

Thanks guys. I called a mobile auto spark in Dundee in the end, chose one with good reviews but wasn't sure how hopeful to be. He came out last weekend and had it bypassed and the car running before I could make him a cup of tea.

Which is tremendous, obviously. I have been away since then and haven't had the time to have a good look at what he did, and I'd best not share it here just in case anyway.

But he said it was pretty straightforward, which is good news for those of us with this system. My advice would be to bypass it now or have it replaced so it can't let you down.

Thanks for the update.

[Orangecurry]

Thanks for updating the thread.

The cognoscenti always made me smile when they bang on and on about keeping the car-alarm factory, and it's a really good system...

Today's car-thief could disable a 1990's alarm with a stern look.