Mounting the computer

Does the computer need to be mounted flat or can I mount it upside or sideways.

I am running the wiring harness I salvaged from the 92 Suburban that donated its 454TBI and 4L80E tranny. There are a lot of wires!!!

What Denny said. Do make sure that the connector is mounted to the side or bottom so that if water does get to it, it has a way to drain. I have mine for my LS1 mounted inside the driver fender with a simple shield to protect it from most road debris.

You can see pictures of mine here:

http://www.hotrodders.com/forum/jour...age=5&reverse=

Pat

There are two styles of ECMs for the industry; sealed and not sealed. You should look at two things to determine which you have..... first, where was the ECM mounted in the original installation? If it was mounted in the engine compartment, it is a sealed unit (with the exception of the breather vent hole). There should be a gasketed type connector(s) on these units. Examples are Chrysler NGC or the GM Vortec controllers. The new Ford Side Exit controllers are sealed. If the unit has a vent plug (a black round plug with a GoreTex center, the unit should be mounted so that the vent plug does not get a direct spray from a car wash.

IF the ECM was originally mounted in the passenger compartment, it is not sealed. Examples are the Ford EEC module and the typical GM ECM. The Ford EEC module has a colored connector gasket but the housing is not sealed on many modules...there was an unsealed programming port on the back side.

The most rugged modules are the engine mounted controllers like the Cummins series and some of the inline six cylinder GM models. They are designed to handle the temperature and shock of being bolted directly to the block...a harsh environment.

Other than the vent plug orientation to keep the spray out, the ECM doesnt care what the mounting orientation is. There is no way to mount the ECM so that the connectors self-drain....if the unit is mounted in the engine compartment, it must be sealed!

If you can, try to use the original mounting isolators (the rubber shock mounts). In the engine compartment, the heat and shock are what kill the ECM. Look at a stock installation to see how it was originally mounted. Many GM underhood ECMs had a mounting cradle...like the Vortec controller.

Mike in Tucson

Mike, What I meant by mount so that it can drain is that on my ECU where the two connectors make their connection to the ECU is inside an oblong aluminum casting that if pointed up could hold water if they were exposed to it. Once the plugs are installed, this would not be likely. But just to be safe, I was advised to install with the plugs pointing either downward or to the side so in the chance that water were to get in there, it would not just sit and possible cause corrosion with the connector. The connectors go in there pretty tight and are held in with a bolt so they may be sealed well enough. But why take a chance if it's an easy choice?

Your reply has lots of good info in it.

Pat

Pat, agreed that mounting the connectors oriented downward might help...but then, the harness connector housing becomes a "pocket" to hold water....although it is a tad more difficult to get water in there. I would mount the ECM the way you suggested...cant hurt. I'm not sure if the factory uses some kind of grease on the connector to help the seal and corrosion problem....there are dilectric greases made for this purpose that might be reasonable to consider.

Also, I forgot to mention grounding.....if the factory grounded the case separately from the harness, do so.....for many of the ECM designs, the circuit board ground is case ground. Following the factory mounting methods can help assure good performance.

Thank you so much!!!!

This will make my life much easier and free up a huge amount of space under the dash. For a 16 and half foot long care there is precious little room under the dash, especially since I will someday install AC.