Montana Owners Club - Keystone Montana 5th Wheel Forum - View Single Post

Desert RVer · 06-13-2009, 10:04 AM

WALA,

We have ignition and liftoff. Installed the new Gas valve and ECM today and now have a water heater working on gas fired again. $200 in parts and shipping costs, a couple hours of trying to locate the ECM, an hour more diagnosing what the real problems were and an hour to try to repair the old ECM. But decided to replace the original Suburban ECM because it didn't have a fuse in the switched 12V output and didn't like the signal quality coming out of the unit. I suspect this would have been a $500 to $600 dealer repair bill, maybe even more. Nothing really difficult once the ECM was found. The only other difficult part was removing the original brass 90 angle fitting from the old ECM so it could be installed in the new one. It was really in there tight. Had to try several different tools before finding one that would break it loose without ruining the fitting. A good multimeter is needed to measure coil resistance, trace continuity on the circuit board and verify voltage is getting to the right places. If you have the original Suburban ECM. it will blow out if either one of the coils chorts out. It burns up the circuit board trace from the relay to the connector doing what a fuse would have done if had been used on the original ECM. On the Dinosaur ECM there is a 5 Amp automotive fuse in this line and an indicator to show the ECM is switching properly. However, if the fuse blows one needs to find out why. Probably will be due to one of the gas valve coils shorting out. Why Suburban didn't use a fuse can only be explained by the fact that they maybe saved $0.50 on the original cost of the ECM and due to this will sell more repair parts because of it. A dealer probably would have charged at least $300 for the parts alone plus at least two to three hours of $90 an hour labor. But now I know where the ECM is located, how it is wired, how it all works and have a better and safer setup than the original from the factory. Life is good. But the real question is: Why didn't the original manufacturers do it right to begin with? I suspect the same setup is used on all RV's that use a Suburban Water heater no matter how much the original cost of the RV is! They need their butt kicked.

06-13-2009, 10:04 AM	#16
Desert RVer Montana Fan Join Date: May 2009 Location: Gilbert Posts: 262 M.O.C. #9307	WALA, We have ignition and liftoff. Installed the new Gas valve and ECM today and now have a water heater working on gas fired again. $200 in parts and shipping costs, a couple hours of trying to locate the ECM, an hour more diagnosing what the real problems were and an hour to try to repair the old ECM. But decided to replace the original Suburban ECM because it didn't have a fuse in the switched 12V output and didn't like the signal quality coming out of the unit. I suspect this would have been a $500 to $600 dealer repair bill, maybe even more. Nothing really difficult once the ECM was found. The only other difficult part was removing the original brass 90 angle fitting from the old ECM so it could be installed in the new one. It was really in there tight. Had to try several different tools before finding one that would break it loose without ruining the fitting. A good multimeter is needed to measure coil resistance, trace continuity on the circuit board and verify voltage is getting to the right places. If you have the original Suburban ECM. it will blow out if either one of the coils chorts out. It burns up the circuit board trace from the relay to the connector doing what a fuse would have done if had been used on the original ECM. On the Dinosaur ECM there is a 5 Amp automotive fuse in this line and an indicator to show the ECM is switching properly. However, if the fuse blows one needs to find out why. Probably will be due to one of the gas valve coils shorting out. Why Suburban didn't use a fuse can only be explained by the fact that they maybe saved $0.50 on the original cost of the ECM and due to this will sell more repair parts because of it. A dealer probably would have charged at least $300 for the parts alone plus at least two to three hours of $90 an hour labor. But now I know where the ECM is located, how it is wired, how it all works and have a better and safer setup than the original from the factory. Life is good. But the real question is: Why didn't the original manufacturers do it right to begin with? I suspect the same setup is used on all RV's that use a Suburban Water heater no matter how much the original cost of the RV is! They need their butt kicked.