[Gmecm] Putting the computer in the engine compartment?

[Jay Vessels]

Hi there!

mark krawczuk wrote:
> hi,  what about using silicone to seal ?

Silicone would work fine for the box but you're still going to have 
water travel down each individual wire.  The ECM connectors aren't 
weatherproof.  You might get away with filling the connector shells with 
silicone but then you couldn't unplug the connectors!  Filling the 
shells without the connection already made would be difficult -- it 
would be hard to seal the individual pin cavities without affecting the 
connectivity of the pins and the shells.

Jay Vessels
1982 Chevrolet S-10 Sport, 2.8V6 TBI
1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)


> 
> mark  k
> 
> ----- Original Message ----- From: "David Allen" <davida1 at hiwaay.net>
> To: <gmecm at diy-efi.org>
> Sent: Saturday, 26 November 2005 3:31 AM
> Subject: Re: [Gmecm] Putting the computer in the engine compartment?
> 
> 
>>
>>> Hi there!
>>>
>>> The problem isn't heat -- it's water.  Water will want to travel along
>>> every seam, opening, and will migrate along the wiring harness.  Sealing
>>> the ECM from water is the chore.
>>
>>
>>  Yes, I learned that the hard way.  My first attempt at a boat ECM box 
>> had
>> the wires going under a notch in the lid.  It filled with water and 
>> wrecked
>> the ECM.  Then I built this setup.
>>  It was easy to install the Deutsch connectors.  Just clip the ECM 
>> harness
>> one wire at a time and insert each wire in the respective connector 
>> one at a
>> time. The holes in the connectors are labelled on each side.  Once 
>> again, if
>> anyony wants info I have part numbers and info on obtaining these 
>> connectors
>> from AGCO/ Caterpillar dealers.  I don't sell connectors and I don't have
>> prices; but I do have part numbers with pictures for 12, 23, and 40-pin
>> watertight bulkhead connectors, terminals, wire seals, and locks.
>>  On my boat, one of the harnesses is battery and ground, ignition 
>> switched
>> power, fuel pumps, ALDL, and other things that are not on top of the 
>> engine.
>>  The other connector is the temp sensor,  MAP sensor, HEI ignition 
>> timing,
>> and all throttle-body components.
>>  There were enough unused pins in the 2 connectors that I was able to
>> design it so if the 2 are switched, the battery power feed will not be
>> connected to anything if the battery/ ground harness is accidentally
>> connected to the TBI harness plug.
>>  Another good box option is a military metal ammo box.  Those things are
>> thin-gauge steel, completely watertight and easy to open.  You could have
>> the ECM and relays in one of those and install watertight connectors 
>> through
>> the box.  It would look better underhood than a Carlon plastic box and
>> probably be more durable. I used a plastic box on the boat to avoid 
>> exterior
>> rusting. You know- since it is guranteed to be sitting in water from 
>> time to
>> time!
>> David
>>
>>
>>
>>
>>>
>>> David's box is a good example of what to do -- notice the wiring is
>>> through weatherproof connectors. That is the key -- it's easy to get the
>>> ECM in a waterproof box, but sealing the wiring's another issue.
>>> Installing weatherproof connectors in the box, and running wiring from
>>> the connectors to the ECM is the right answer.
>>>
>>> Jay Vessels
>>> 1982 Chevrolet S-10 Sport, 2.8V6 TBI
>>> 1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)