My buddy's 86 k5 died last night while driving. No power o ECM, thinking that the ECM wouldn't just up and die, need to check the fuse. I checked the fuse box last night and didn't see an ECM fuse, is it somewhere else?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
86 k5 ecm fuse location
- Thread starter 76k5blazerr
- Start date
Anybody know where that fuse is at?
This is an '85 diagram,should be the same..looks like the ECM fuse is the one on the lower left side of the picture..
And you said in the other post "pink wire to ECM has no power". If that diagram is right, as is pretty typical on GM's setups, the pink wire isn't connected to the ECM, it's off the fuse panel.
Don't get wrapped up in the ECM. No spark at crank should have nothing to do with the ECM, the module controls all spark under 400RPM (cranking).
Don't get wrapped up in the ECM. No spark at crank should have nothing to do with the ECM, the module controls all spark under 400RPM (cranking).
I traced the pink wire I talked about in the other post through the firewall to the ECM. That wire had no power in any key positions (off on and start) pretty sure that would be what's causing the no spark right?
Any way you could link that diagram up? I can't see the pic cause I'm not a paid member yet.
Don't know if I could figure out how to e-mail it to you--I found it by googling "1986 Chevy truck fuse box diagram" under "Images" and several sites popped up with the image...
There is an ignition fuse also in the fuse box..if you hot wired the "BATT" terminal the pink wire goes to on the distributor cap right to the battery positive,that will tell if it has spark or not..and confirm the wire is faulty or not receiving power from the fuse box..
There is an ignition fuse also in the fuse box..if you hot wired the "BATT" terminal the pink wire goes to on the distributor cap right to the battery positive,that will tell if it has spark or not..and confirm the wire is faulty or not receiving power from the fuse box..
Ok. I'm going to try that. So let me get this right... Run a wire from positive battery terminal to the terminal that the pink/red ignition wire goes too on the dizzy cap? As in unplug the ignition wire and plug in the hot wire from the battery? Sounds like it would work, wouldn't it make the engine spark at all times that the wire was hot though?
Yes--it will not shut off (if it starts) ,until you unplug that jumper wire..
Great, I'll let yall know how that goes.
Ok guys, did that hot wire trick, got nothing, also tested the tach terminal on dizzy cap and it lights up when the key is on and when you try to start it. But it won't start still. Also, I found the ecm 1 and 2 terminals on the fuse block, there are no fuses or terminals for the fuse to go into. Any ideas yall?
It's not really an ECM I expect. It's an ESC/EST controller. The panel probably has the ECM slots for CA trucks that were using CCC at that time.
Being EST/ESC its going to throw a curveball into how to diagnose, however the majority of the steps given here are likely applicable to the setup you are dealing with http://forums.hotrod.com/car-craft/...ft-discussion/gm-hei-ignition-module-testing/
Is there continuity from either end of that pink wire you are talking about?
Being EST/ESC its going to throw a curveball into how to diagnose, however the majority of the steps given here are likely applicable to the setup you are dealing with http://forums.hotrod.com/car-craft/...ft-discussion/gm-hei-ignition-module-testing/
Is there continuity from either end of that pink wire you are talking about?
My buddy wants to replace the cap and rotor tomorrow, and plugs and wires, because he can't afford a whole new dizzy right now. But we are suspecting it's a dizzy problem. Because today we basically bypassed everything that could be bypassed and still got no spark.
Uh, for the price of what he is talking about replacing you are damn near a new distributor. They are about $100. For plugs, wires, cap OR rotor to cause a no spark condition, you'd clearly be able to see the problem. Absolute waste of money. Not going to help get the truck running if he is broke.
Of course, if you keep the ESC, it is probably going to cost more. It's pretty common to ditch that system.
Either test the system, or replace the whole distributor and hope you made the right choice.
Of course, if you keep the ESC, it is probably going to cost more. It's pretty common to ditch that system.
Either test the system, or replace the whole distributor and hope you made the right choice.
If it were my truck I would bypass the entire system, not sure what he wants to do. How hard is it to bypass the whole thing. Sorry for seeming like a newb I've never worked on a k5 made after 79 so I'm new to all this ECM est stuff.
The EST system doesn't have many followers, at least here. Going to be pretty hard to find someone that is willing to invest the time to figure out why it's not working, it's so simple to completely bypass it that is what the majority do.
It was used on the 305's because they were high(er) compression with crappy heads, so GM was apparently worried about detonation. They must have been extremely cautious, as I never heard a knock/ping from it afterwards, and I still don't hear of people mentioning it, even with ethanol which should be more likely to ping than the older gas. EST/ESC was a way to run a knock sensor/control timing in that event. More than a few of us have removed the system and had zero issues related to it long-term with the motors.
It was used on the 305's because they were high(er) compression with crappy heads, so GM was apparently worried about detonation. They must have been extremely cautious, as I never heard a knock/ping from it afterwards, and I still don't hear of people mentioning it, even with ethanol which should be more likely to ping than the older gas. EST/ESC was a way to run a knock sensor/control timing in that event. More than a few of us have removed the system and had zero issues related to it long-term with the motors.
Where can I find a step by step on bypassing it?
Pretty sure the step by step is pull old distributor, install non-ESC distributor, make sure to connect ign. hot to proper terminal on new distributor, done.
I haven't messed with carbed systems for a long time, but as I recall, the only wire run to the big cap HEI is the ignition hot, which is clearly marked on the non-EST cap where it goes. Might need to use a 1/4" spade terminal to connect to the ignition lead, but it's real basic.
I haven't messed with carbed systems for a long time, but as I recall, the only wire run to the big cap HEI is the ignition hot, which is clearly marked on the non-EST cap where it goes. Might need to use a 1/4" spade terminal to connect to the ignition lead, but it's real basic.
onedaatmc
1/2 ton status
different fuse diagram
I have a 86 K20 Diesel ... and all my dash guages stopped working ... I'm trying to figure out which fuse needs replacing and nothings labeling and there's no cover ... so by chance does anyone have a pic of the fuse box I have ?
Thanks in advance
ps ... no avail on a google search for it
I have a 86 K20 Diesel ... and all my dash guages stopped working ... I'm trying to figure out which fuse needs replacing and nothings labeling and there's no cover ... so by chance does anyone have a pic of the fuse box I have ?
Thanks in advance
ps ... no avail on a google search for it
Check the link in my sig. I *think* the electrical manual is the one with the fuse panel diagram. You'll need something close to your year, don't know exactly what year, but there are two different styles of blade fuse panels, early and late. I suspect late started in '84 or '85.
