I have a 1991 420sel (gas) that I inherited through my father. During the last couple of years, because of age the vehicle has been neglected. I am now having a problem with the alarm/door? After extensive rain here in Tampa, the vehicles' alarm was going off every time I opened a door and would not stop. I had to wait it out. The vehicle started with no problem. I moved the vehicle to another area in the driveway same thing. I waited it out. I then went to start the vehicle the other day with no avail. I even disconnected to module to the alarm system. What else can I do, I need guidance. It turns over but will not start.

New to a used vehicle......Lauren

First off, make sure the car does not have an aftermarket alarm system added to it.. Also, where did you access the alarm module?

__________________
2001 E55

2001 E320 Sedan

2001 Subaru Legacy

2006 SLK280

2016 Subaru Outback 3.6

If it does have an aftermarket alarm, it more than likely has a starter interruption when armed. This model also has FPR failure too....

FPR = Fuel Pressure Regulator

OR

FPR = Fuel Pump Relay

?

The alarm is the original Becker that came with the vehicle and as for the FPR. I know it was changed once. I know where it is located, but how to I check the amps (which pins and readings)?

@ Two560Two - The door panel to the alarm system is on the passenger side floor panel against front wall (basically if there was a glove box it would be located underneath). There is an access panel with a 8 or 10 mm nut.

Two of the most basic things may be happening. No spark or no fuel. It's easy enough to check the fuelpump without doing much other than checking to see if the fuel pump is running while cranking. Just look just inside of the right rear wheel to check. If it isn't running, you may want to want to jump #87 and 30 where the FP relay plugs in. If it still doesn't run you can check for power at the FP terminals to rule out if it's bad or not. If it runs, you may want to move on to the spark....

make sure the trunk lock is not causing you this grief

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

If you unlock the door and, once you have it open, the alarm still goes off, "unlock" the door one more time with the key. That is what I used to have to do to turn off the alarm on my 88 420SEL. This affliction had started after a deluge of rain as well.
Good luck!

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Okay, the Fuel Pump Relay is good. I have yet to challenge the fuel pump itself (but will when I have support)...in the meantime. I re-hooked up the modules to the alarm.

On another thread, I read in regards to the alarm system - because I just believe this is the problem. I tried the master key in the trunk and locked the doors counter clockwise to set the alarm. I can not pull the key out at 9 o'clock, but I can at three. I noticed the vacuum pump (located in trunk by spare tire) motor runs after engaging locks.

Any thoughts???

Thank you all for your support - I'm new at this.

When you twist the key in the trunk to the 3 o clock position it locks out the press in function of the button (dead locking it in place), locks the car and also arms it.

If you lock the car with the trunk and then try to unlock from the doors - it will set off the alarm (at least thats what it does on my W124). I have sprayed some superlube in the latch and also the tumblers and switch contacts to clean and lube them.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Thank you for everyone's help and ideas. I did lube up the locks making it easier to insert keys, etc. Found the driver side actuator assuming to be bad, that is what is making the pump in the trunk run I believe. - .

As for listening to the fuel pump - we did with no noise. Check for electrical going to fuel pump (there is) but the pump would not kick on. We added fuel directly to the carburetor and started vehicle and it ran twice until fuel evaporated. Leaving us determined to change the fuel pump.

Before we start, does anyone know if there are two pumps? If so, where is the second one located?

I will let you all know the status when the job is complete!