MEP-802A No Response to Control Panel Functions Including Start Switch

[Bmxenbrett]

All 3 of those plugs look to be fine. Sprayed some contact cleaner in them also.

 

[DieselAddict]

Download this drawing - https://drive.google.com/file/d/0B2...=sharing&resourcekey=0-SnpdiqMIwRdo7zl525x0sQ

Look at the test points in the triangles. Those correspond to the pins in that big diagnostic connector on the left side of the machine.

Start tracing it down and find where you loose full voltage. Do you have 24v on term 3 of S1? Do you have 24v on TP d on the diagnostic plug?

 

[kavesman1]

Since you said the 803A turns over fine with the dead crank switch, your problem should be between the Dead Crank Switch and the E Stop. Pin 3 of the D.C. switch connects to Pin 1 of the E Stop switch. Check the E.Stop pins while the button is pulled out for 24v DC +/-. IF you have voltage there, the the fault will be between it and the CB1. IF not, the your problem lies in the P7/J7 junction connector. The circuit passes through that at pin #14. Check both sides of the connector for a loose connection or a broken wire between the D.C. switch / E Stop Switch to it. Below is what the diagram/location of it.

 

[Guyfang]

All 3 of those plugs look to be fine. Sprayed some contact cleaner in them also.

The canon plugs have been looked at. And that would have been my first guess anyway. The main voltage comes up to the control panel from the starter + side. Trace the voltage back from there.

 

[Bmxenbrett]

No power at TP D on the diag plug. I have 24v at terminal 3 on the DCrank switch until i turn the master switch from the off position.

 

[Bmxenbrett]

It appears as if im loosing the voltage over CR1. I even jumped it out quick and the fuel pump turns on fine. Any one know the specs on this diode?

 

[jamawieb]

Remind me which one is CR1. I'm not around my units to see. Is it the very bottom diode on the Burden Resistor bracket?

 

[Bmxenbrett]

I thinknits 2nd from the bottom on that board. I found ebay had them 10 for $.99cents

 

[jamawieb]

Ok. If it's 2nd from the bottom its a 1N5406 diode. 2nd and 3rd from the bottom are the same.
Bottom is a resistor part # V68MA3B crosses to a F2286-ND.

 

[Guyfang]

Here is some tech data for you all. Diode 1N5406

	INCLOSURE MATERIAL	GLASS
	OVERALL LENGTH	0 3/8 INCHES MAXIMUM
	TERMINAL LENGTH	1 1/8 INCHES MINIMUM
	OVERALL DIAMETER	0 21/100 INCHES MAXIMUM
	MOUNTING METHOD	TERMINAL
	FEATURES PROVIDED	HERMETICALLY SEALED CASE
	SEMICONDUCTOR MATERIAL	SILICON
	VOLTAGE RATING IN VOLTS PER CHARACTERISTIC	600 MAXIMUM REPETITIVE PEAK REVERSE VOLTAGE AND 600 MAXIMUM WORKING PEAK REVERSE VOLTAGE AND 800 MAXIMUM NONREPETITIVE PEAK REVERSE VOLTAGE, MAXIMUM PEAK TOTAL VALUE
	CURRENT RATING PER CHARACTERISTIC	3 AMPERES FORWARD CURRENT, AVERAGE MAXIMUM
	MAXIMUM OPERATING TEMP PER MEASUREMENT POINT	170 DEG CELSIUS CASE
	TERMINAL TYPE AND QUANTITY	2 UNINSULATED WIRE LEAD

 

[mlaxton]

OK NBA! Now you are ready to start. You have the CLEAN schematics, (thank you DieselAddict!!) and with the troubleshooting you can get started. If the engine turns over with the S-10, dead crank, batteries are not the problem. The Dead crank's function is not to start, only to turn over the engine, WITHOUT starting it. Plenty of good reasons for that, like bleeding the fuel system to the injectors, or adjusting the Mag Pickup.

So if it cranks with the S-10, you have learned a lot. Now, no input to the controls. Look at your manuals and schematic. Open the control panel. Find the MT-4, (battery ammeter shunt) to the right, on the bottom of the control panel. Take your multimeter, (hope you have one) and measure DC voltage. From the frame to BOTH sides of the shunt. You should get approx 24 volts, or what ever your batteries have in them. If you have voltage on one side, and not the other, there is the problem. The shunt doesn't often go bad, but it can. If you have DC voltage on both sides of the MT-4, then look to the left. Find CB-1. It should be pushed in. Pop it out push it in. Then take your handy dandy voltmeter, and measure from the frame to both side of the CB-1. Got power on both sides? Good. If not there is your problem. CB-1.

If you had NO DC voltage at the MT-4, reach up with your hand, on the right side of the control panel, through the small door on the bottom. There are some canon plugs up there. Unscrew them, and screw them back in. Measure again at MT-4. Sometimes these canon plugs are not connected, loose or the pins are burnt off. Pull the plugs down, look into them to see if the pins are there, not burnt off or corroded. These are quick disconnect plugs. They should easily twist on and off. If they feel funny, they could be not making contact.

If you have power to MT-4 and CB-1, look at the middle of the control panel door at S-17, the emergency off switch. Same deal. You should have 24 volts in, and 24 volts out.

I will leave it there. You let us know what you find.

I am having the same issue this gentleman was, I checked both batteries, both are correct voltage. I have proper voltage in all spots you mentioned above. My panel lights will come on very dim but when you move selector switch to prime and run they will go out. The unit will crank just fine with the dead crank.

 

[kloppk]

I am having the same issue this gentleman was, I checked both batteries, both are correct voltage. I have proper voltage in all spots you mentioned above. My panel lights will come on very dim but when you move selector switch to prime and run they will go out. The unit will crank just fine with the dead crank.

From your description I'd suggest the following...
1) Put the Dead Crank Switch (S10) in NORMAL, Emergency Off Switch (S17) Pulled OUT and Circuit Breaker CB1 pushed in
2) Attach your hand held meters ground lead to chassis ground.
3) Put the Master Switch (S1) to the Prime/Run position.
4) Measure the DC voltage at each the two terminals on S17. It should be about 24 volts DC.
5) Measure the DC voltage at each the two terminals on CB1. It should be about 24 volts DC.
6) Measure the DC voltage at terminals 2,4,6 & 8 of S1. It should be about 24 volts DC.

Post up their voltage reading for above and we'll go from there.

 

[Guyfang]

Check the two C-plugs under the control cube, to see if they are good, they are tight. LOOK into both sides of the connections.

 

[mlaxton]

From your description I'd suggest the following...
1) Put the Dead Crank Switch (S10) in NORMAL, Emergency Off Switch (S17) Pulled OUT and Circuit Breaker CB1 pushed in
2) Attach your hand held meters ground lead to chassis ground.
3) Put the Master Switch (S1) to the Prime/Run position.
4) Measure the DC voltage at each the two terminals on S17. It should be about 24 volts DC.
5) Measure the DC voltage at each the two terminals on CB1. It should be about 24 volts DC.
6) Measure the DC voltage at terminals 2,4,6 & 8 of S1. It should be about 24 volts DC.

Post up their voltage reading for above and we'll go from there.

Ok also here is a better discription

Having an issue with my 802a, it runs my hunting camp. Last night it shut down, no fault lights. Nothing.. Tried to crank it Nothing… I thought maybe the alternator went, checked battery voltage both were 13V and 12.9. Read a thread on SS, I checked volts at MT4, CB1, and FU1 fuse seems to be fine, I even jumped it with a piece of wire. The unit will crank strong with dead crank switch, but does nothing on the panel. I did notice after you crank with the dead crank switch the panel lights will come on dim, when you turn to prime and run, the pump won’t come on but the needles on all the gauges jump as they always do. Once you go to crank it at the panel everything shuts back off again. Until you crank with dead crank. I checked battery terminals, hot lines on the starter, All right and good. I’m in the woods pretty far out, limited resources and cell service. Anyone encounter this before?

 

[mlaxton]

From your description I'd suggest the following...
1) Put the Dead Crank Switch (S10) in NORMAL, Emergency Off Switch (S17) Pulled OUT and Circuit Breaker CB1 pushed in
2) Attach your hand held meters ground lead to chassis ground.
3) Put the Master Switch (S1) to the Prime/Run position.
4) Measure the DC voltage at each the two terminals on S17. It should be about 24 volts DC.
5) Measure the DC voltage at each the two terminals on CB1. It should be about 24 volts DC.
6) Measure the DC voltage at terminals 2,4,6 & 8 of S1. It should be about 24 volts DC.

Post up their voltage reading for above and we'll go from there.

readings are

Battery voltage tested prior and confirmed holding with switch in prime and run. All terminals tested 25.6 with switch in off position.
In on position as follows
S17 = 4.2/4.2
CB1 =6.1/5.1
S1 = 2-6.2 4-4.4 6-4.5 8-4.5

 

[kloppk]

Looks like you're not getting adequate 24 volts from S10 to the front panel area due to a poor connection.
It's likely an issue with the connection of P7 to J7. The 24 volts from S10 flows thru pins P7-14 and J7-14 on its way to S17.
I'd suggest you disconnect P7 from J7 and examine the pins for corrosion.
To remove P7 from J7 you'll need to turn the locking collar on P7 CCW. Doing so will unlock P7 from J7 and draw P7 from J7 as you turn the collar.

With S10 in the NORMAL position this is the path from S10 to the front panel.
S10-3 ------- P7-14------J7-14 ------ S17-1

 

[nextalcupfan]

I would also check MT4, that should have 24 volts all the time.

 

[mlaxton]

Looks like you're not getting adequate 24 volts from S10 to the front panel area due to a poor connection.
It's likely an issue with the connection of P7 to J7. The 24 volts from S10 flows thru pins P7-14 and J7-14 on its way to S17.
I'd suggest you disconnect P7 from J7 and examine the pins for corrosion.
To remove P7 from J7 you'll need to turn the locking collar on P7 CCW. Doing so will unlock P7 from J7 and draw P7 from J7 as you turn the collar.

With S10 in the NORMAL position this is the path from S10 to the front panel.
S10-3 ------- P7-14------J7-14 ------ S17-1

I think we are on the right track, after removing P7 i inspected and found no corrosion, after reinstalling the unit fired up, although it only ran for about three minutes and shut back down. No indicator lights came on at all. The fuel pump did stay working, we repeated this about three times with the same results. I did double check the alternator positive terminal once more while it was running and had 28v. Here is a picture of the terminal.

 

[kloppk]

I'd suggest hooking you voltmeter to meter M7 terminal I. The I should be embossed in the case of the meter by the terminal. Connect the meter negative to chassis ground. There is a ground stud on the right corner on the front panel.
Start the set and monitor the voltage on that M7 terminal. It's supposed to stay at 24 volts. Watch to see if it drops out the moment the set stalls. If it does then there is an intermittent power connection that will need to be located.

If power drops out there when it stalls repeat connecting your meter to one of the used terminals on the Emergency off switch.

 

[jmenende]

My 2 cents from recent experience. Many of the 802/3 that I have been receiving from auctions have a jerry rigged disconnect cable running from one of the emergency stop terminals through a hole on the bottom of the control cube to the cable lugz (where there is a male and female spade connector) and then back up to the e-stop terminal. I just remove it completely and put the original cable right back where it goes on the e-stop. This will cause a no power issue on the control box and the manual will not mention it.