88 740 GLE Sedan - Will not start after radio install

A friend installed a radio in my 88 740. Noticed that the battery was
dead next morning. Took the radio out. Battery went stone dead
overnight. Bought a new battery ( other was 6 years old) Car will
not start. Can smell fuel, but no fire. Checked all fuses in the
dash. OK

Any help is appreciated.

 

Did he connect power using the original connector or did he connect to
a wire from the ignition switch, and did you break a connection when
you took the radio back out.

Taff.........



www.sounds-pa.com | www.thecomputerworkshop.com

 

He used a kit that came with the radio. I had it in the car before.
Was thinking about selling so I pulled it out. Reinstalled the
original. The wierd thing was when I put on the brakes hard the door
chime would go off.

The car had a antitheft switch installed at one time. What circuit is
normally broken to keep the car from starting. It's an auto so there
is no clutch circuit. Any other common circuits to break?

Thanks.

 

A friend installed a radio in my 88 740. Noticed that the battery was

One thing I noticed after three radios on my old 240. Two radios used the
factory connector without problems. The third with an internal CD had a
problem when I hooked it to the connector - blown fuses and other weird
electrical things happening. Turns out that it was the ground connection in
the connector. When I grounded it directly to the chassis, all problems
immediately disappeared. But when I tried to use the ground in the connector -
I had all kinds of electrical issues. I suspect that the new radio had a
floating ground ? that was the cause of the problems.

 

This depends how secure the person that fitted the switch wanted it to be,
on my 740 I've used an electronic immobiliser to interfere with some power
and signal wires going to the engine management brain, also the starter
circuit is connected to my car alarm, normally it doesn't turn if the alarm
is armed/disconnected, but this can be defeated with 3 slightly healthy
braincells and a chunky screwdriver on the starter solenoid, if this is done
to mine it turns, but as with yours, there is abolutely no spark.

You will have to trace which wires have been messed with, but it is quite
possible that they were near the radio somewhere, so you could have
disturbed them.

Sorry I can't help more,
Ken