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Have you ever heard the stories about the ignition module going bad and wondered why? Pull over after driving for an hour on a hot day and put your hand on the module. You will pull back with some burnt fingers. That module is filled with semiconductors and their main enemy is heat.
I got tired of looking at the rats nest of wires under the hood and the premature failure of the ignition module, so I decided to move it inside of the cab. It is a simple matter of unplugging the wires from the wire harness under the hood and pulling the harness back inside of the cab. The firewall grommet releases by squeezing it down from the engine compartment side and pushing it back through the firewall. Remove enough of the wrapping from the harness to locate the wires to the module connectors, cut them near their centers so that you have enough working room to splice them back together and pull the wires back through the firewall grommet. Splice them back together with additional six inch long pieces of wire. Solder the splices and insulate them with shrink tubing. (This extends the connectors long enough to give additional mounting flexibility) Pull the wire harness back into the engine compartment; snap the firewall grommet back into place and plug every thing back in. You now have the module connectors inside of the cab and extended an additional six inches. Move the headlight dimmer switch an additional 1-½ inches further away from the kick panel and mount the ignition module to the kick panel just under the fresh air intake duct. (You may have to move the emergency brake pedal over to clear the module) The truck should start right up if you wired the connectors correctly. The module will stay cool to the touch from now on.
This project is not for everyone, but if you want to clean up the underhood wiring and protect the module from excessive heat then this project may be for you.
agreed. the outside looks great...I'm wondering if there is room up under the dash somewhere so it would be hidden (to keep the inside clean looking also)?
agreed. the outside looks great...I'm wondering if there is room up under the dash somewhere so it would be hidden (to keep the inside clean looking also)?
Should be plenty of room to the right and above the fuse block. May complicate changing it out though. Working up there is a pain.
Be cool to have that fresh air vent provide some cool air for the box.
Or fab up a housing / ducting and use a 12vdc computer power supply fan to blow air on it. About $15 or free if someone is scrapping an obsolete PC. Very little draw.
There has been some positive reaction to my project. The module could be mounted anywhere inside the cab that is convenient. The idea is to get it out of the engine compartment. I don’t think people realize how hot it gets inside of the engine compartment. The 460 creates a lot of heat and it is even greater if headers are installed. I don’t think venting the module is going to do much if it is still in the engine compartment. Also remember that the module needs to be mounted on a mental surface. This works as a heat sink for the module.
We all get that.
And we like what you have done.
Just throwing some ideas out there to get some air moving over it.
The heatsink aspect doesn't provide all the cooling. It does need air moving across it. That's why the mounting feet are arraigned so there is air under the body.
There has been some positive reaction to my project. The module could be mounted anywhere inside the cab that is convenient. The idea is to get it out of the engine compartment. I don’t think people realize how hot it gets inside of the engine compartment. The 460 creates a lot of heat and it is even greater if headers are installed. I don’t think venting the module is going to do much if it is still in the engine compartment. Also remember that the module needs to be mounted on a mental surface. This works as a heat sink for the module.
Oh yeah it gets hot in the engine compartment... my ICM's insulating goo has melted and run down the inner fender. The ICM still works but now I carry a spare. That prompted the head scratching and idea about a blower housing on my end.
I know, an old thread here ... but then I just found it, at least I don't recall it. I am reminded of how my Dept. garage took to relocating a "lean burn" computor from the air cleaner side into the passenger side dash in the car to fight the same issue .... heat.
I was going to build a deal to lift my DS box off the apron surface there near beside the exhaust, to shield it, to turn it open side up so any potting stays inside .... but this looks interestingly better. Could still mount it open side up, but under my dash, out of the engine compartment.
I've only had one fail, it was the original, failed maybe 10 years ago, but cooling with cold drink got me going. My spare stored in the truck behind the seat was thankfully in a box, as it's potting had got hot enough to run out inside the box behind the seat, just from summer heat buildup. It had never even been used, but it works still (I tested it) and I have a second new in box one, stored open side up in its box. The one I have now under the hood was bought new too, and so far is good.. I would not move and remount one in a position where hot summer heat might lead to soft potting on my floor or carpet ... or my boots.
I'll revisit this when Spring finally starts for sure.
I also had the box on my 81 F100 leak potting out down the inner fender just from heat and I got a 300 six
It is also still good as I tested it not long ago.
Dave ----
When that potting melts is can be a GIANT PITA to get it off the dvrs inner fenderwell. Just add a couple of washers to space it off the inner fenderwell and go. Same for when you fry your voltage regulator due to a faulty battery cable. There is a potting in that too and it stinks to high heaven for a while and that stuff is also hard to get off the passenger side of the inner fenderwell.
When that potting melts is can be a GIANT PITA to get it off the dvrs inner fenderwell. Just add a couple of washers to space it off the inner fenderwell and go. Same for when you fry your voltage regulator due to a faulty battery cable. There is a potting in that too and it stinks to high heaven for a while and that stuff is also hard to get off the passenger side of the inner fenderwell.
I was gonna do the spacing, but after I found I had to cut the box away from one (stored behind my seat in the darkness) due to it's potting running out while still in the box and gluing it all together ... just summer heat melted that one. After trimming the hardened goo / cardboard mess away from it, it still worked so there was that. Even openside up, the potting can melt, but I'd hope it would stay inside the case.
I think that the potting is just a means to prevent vibration damage ... and that the internal components might actually run cooler or even last longer without the potting ... if otherwise insulated from vibrations? I wonder if a good ground wire to a mount a hole and using a couple bungie cords to suspend the box in free air or in front of a vent ...? It isn't the movements of vibrations that can harm electronics as we are all moving all the time here on Earth ... rather it's the rapid & repetitive sharp stops and reversals of movements of vibrations that I'd say harm electronics.
Like shaking your head to indicate "NO" ... or turning it to look at Barbara as walking by ... doesn't hurt unless your head hits an overhanging Bunson burner shelf on the cinder block wall next to you in science lab .... those shelves did not move (our school had one on each of the little shelves about 5 feet off the floor, an instructor could tell at a glance if one or more was not back on it's shelf, unhooked, not lit). Just the memory still hurts 55 years after ... but I'm still here ... and I have no idea of where she is these days as her folks sold the motel and drive inn theater and they all moved away.
I did long ago replace my '77's mechanical VR with a solid state type VR as used on some later Fords. It (mine) mounts up on the radiator support, on the right, near the battery too. I never heard of one leaking in normal service as likely they run cooler I guess. I guess a bad cable could maybe overwork it though?
11-10-2014, 02:19 PM
I wonder if a good ground wire to a mount a hole and using a couple bungie cords to suspend the box in free air or in front of a vent ...? It isn't the movements of vibrations that can harm electronics as we are all moving all the time here on Earth ... rather it's the rapid & repetitive sharp stops and reversals of movements of vibrations that I'd say harm electronics.
Just the memory still hurts 55 years after ... but I'm still here ... and I have no idea of where she is these days as her folks sold the motel and drive inn theater and they all moved away.
