rattle_rattle

I noticed that when I started the beast tonight the headlights would seem to cycle between being dim and bright. The voltmeter seemed to follow this dimming but had a lag to it. The lights would dim and the voltmeter would read 14, then after a second or two it would drop. The lights would go back to full brightness and the voltmeter would stay low for a second or two then go back up to 14. This was with a cold engine. It seemed to quit this after the engine warmed up. Is the intake heater cycling on and off after the engine is running? This is the first time it has been cool weather since I got the truck and it seems to be happening after the weather turned chilly. Is this normal? I even noticed it happening a little after only being shut down for a few minutes. Has anyone else experienced this voltage fluctuation?<br>

phox_mulder

Yes.<br><br>I got mine right at the end of the cold weather last spring, and noticed that as well.<br><br>It stopped when the temps got up after a couple of months.<br>Now it is doing it again.<br><br><br>phox

rattle_rattle

phox,<br><br>Thanks... I get a little scared when something like that happens.<br><br>Gary<br>

phox_mulder

This is my first Diesel and first Dodge.

If not for this board and all the friendly people, there's been a bunch of things that I would have been needlesly worried about. And some that deserved worry.
Strange noises, odd behavior, odors .

I'm sure there are more to come as well.


phox

rattle_rattle

This site has saved my bacon several times! Not to mention my sanity (well... maybe..) It has become a routine before going to bed to check the DTR site. Great bunch of guys (and gals). I'd listen to anyone on this site before I believed anything said by DaimlerChrysler. Here is where you get it straight! ;D<br><br>Gary<br>

dan239

That's your air intake heaters coming on and back off until the engine heats up a bit.<br><br>The first time my old 92 did that, I thought I had a very serious problem. It was at night and my headlights were dimming when the heaters were kicking in. I had not noticed it during the day after the weather turned cold. But, the first night, it really got my attention. I was relieved to find that it was normal.<br><br>Dan

Commatoze

Yep, same thing here.

cr1998

[quote author=dan239 link=board=5;threadid=5901;start=0#52941 date=1034658429]<br>That's your air intake heaters coming on and back off until the engine heats up a bit...[/quote]<br><br>So that's what causes this. Same thing happens here. Thanks Dan. <br><br>CR

hellotbone

Yep thats the cause mine does it to not to worry. If you stan outside you can really hear the idle changing too!

yomitch

what actually happens is that the batteries have a small internal resistance due to the lead in the batteries. before this big resistor (like a toaster) clicks in your battery voltage is about 13.8 volts, now when the toaster turns on it draws a whole whack of current. Because of this internal resistance the actual voltage at the battery terminals (volt meter) drops because all the power is not being dissipated in the heater, some of it is being dissipated in the battery. This cycling continues until the engine warms up. I've seen a b type cummins in a ford 3 ton without this heater up here in Canada<br>and the cops pulled him off the road due to the white smoke.(probably incompete combustion)<br> This voltage drop happens when you start the engine as well due to the high current to the starting motor. <br> This is why also that there are two batteries, to increase the amps and also to get more voltage to the starter and the toaster.

yomitch

so basically the toaster is to warm the air up going into the combustion chamber so there will be more complete combustion when the engine is cold.<br>You should see volvo low compression engines when they start, it looks like the wicked witch of the west is coming!

Redleg

Just noticed mine doing the same thing, first year, first winter with a Cummins. My truck only came with a single battery, was thinking two might reduce the draw and preserve the battery life. After reading this I guess it's not gonna go away. Was it common to go with a single battery? I,m a little surprised as this was a tool truck for a concrete co., has a flat bed and all the running lights.

Michael Az

[quote author=RTO link=board=5;threadid=5901;start=0#53522 date=1034775883]<br>Just noticed mine doing the same thing, first year, first winter with a Cummins. My truck only came with a single battery, was thinking two might reduce the draw and preserve the battery life. After reading this I guess it's not gonna go away. Was it common to go with a single battery? I,m a little surprised as this was a tool truck for a concrete co., has a flat bed and all the running lights. <br>[/quote]<br><br>As you live in Mich, it might be a good idea to reinstal the other battery and use your block heater this winter for easier starting.<br>Michael

Redleg

Michael.... come to think of it, they probably did store it in their shop at night. I,m sure it only came with one battery though. No extra mounts or wire anywhere. I guess I will need another anyway as I'm planning on getting a plow. Also gonna pick up a timer as has been posted, for plugging in the block heater.<br><br>Don

dan239

[quote author=RTO link=board=5;threadid=5901;start=0#53664 date=1034784652]<br>Michael.... come to think of it, they probably did store it in their shop at night. I,m sure it only came with one battery though. No extra mounts or wire anywhere. I guess I will need another anyway as I'm planning on getting a plow. Also gonna pick up a timer as has been posted, for plugging in the block heater.<br><br>Don<br>[/quote]<br><br>All 1st Gen trucks [89 thru 93] came with only one battery. In most situations it was more than enough. It is a heavier battery than the ones in 94s and up. My 92 had a battery rated over 1000 cold cranking amps.<br><br>Dan