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View Full Version : Troubleshooting a starting issue 85' 4d55



fourthcummins
01-01-2012, 04:34 PM
Hi, I have a starting issue with my 1985 ram 50 diesel 4d55. I parked it once on a rather cold day and left it for maybe three hours, and when I came to start it, the glow plug relay wouldn't click, and it didn't start. It turns over just fine, but it does not start. I found later that it does start easily when I plug in the block heater overnight. I installed a momentary switch to the glow relay, and now it clicks, but still won't start when cold. In addition, I found that there is a 12 volt drain on the battery somewhere. If someone knows where that might be, please help!. Other things I have done are change the fuel filter and air filter, change the glow plugs, tried a different battery.
The symptoms include:
1 Not starting cold
2 No Glow Plug Relay click
3 A 12v drain on the battery
So there you have it, don’t hold back any suggestions, I really need the help.
Thanks, R.C.

camoit
01-01-2012, 09:08 PM
The drain can be in the alternators regulator. Try unplugging the alternator for the night.
Also if the battery is dirty it can drain the battery. To check that just take your volt ohm meter and set it on voltage. Then put one probe on a terminal and the other on the top of the battery. More then 2 volt you need to clean the battery.

wrngwae
01-02-2012, 07:28 AM
im not too sure on the drain, try to unhook the power wire to the alternator. but as far as the no start issue. pull the glow plugs out and clean the tips and test them for heat....... the super easy cheep way it to just use some wire right off the battery to see if they heat....lol watch out they get hot fast!!!! how long are you holding your button manually?? i would only hold it for about 10 sec at a time.

fourthcummins
01-02-2012, 01:04 PM
Thanks guys. I unplugged the alternator and the glow relays started clicking on their own with the ignition, but don't turn off automatically. It looks like the alternator is at fault. Wrngwae, I tested the old plugs and they work fine! arrgh! that was 95 non-returnable dollars.

pennyman1
01-02-2012, 05:24 PM
Now you have 4 spare glow plugs - doesn't seem like a good thing now, but it will be sometime in the future.

camoit
01-02-2012, 10:58 PM
It sounds like there might be a fault in the timer also. It works off of power draw to the glow plugs. That is why when you turn on the key they will click once for a long time then click in quick secession when they get hot, to stay hot. But only for a certain amount of time. Then it will shut down. After that it needs to cool down again before it will allow a reheat. This will only happen if the temperature sensor allows the timer to work.

But if it just goes click,click, quickly then glow plugs are going out.

fourthcummins
01-02-2012, 11:06 PM
Do you mean the glow control unit? I don't think that is broken. Does anyone have a good alternator swap part? the oem replacement is big $. Or is it just the voltage regulator?

camoit
01-02-2012, 11:37 PM
find a local rebuild shop have them check it out. Or you can replace the regulator. You might be able to find one at napa. It's inside the alternator. so if you look inside you will see it. I would just go to a rebuild shop.