After having my 89 7.3 plugged in for a few hours yesterday when it was -20C/-4F it didn't want to start. It has two new 850CCA Group 65 Walmart batteries. I normally would get brand name batteries but they previous owner just put these in before I bought the truck. After cranking it for about 10-15 seconds it would start to chug but not start. I popped the hood and could see frost on the engine. I knew either the block heater cord or the heater itself wasn't working.

I put a digital multimeter on 20 ohms and checked the + and - leads on the male plug after cleaning them up with some sandpaper. It read open with no resistance. So now I have confirmed there's a problem. Today it's -37C/-34F with the windchill and it's suppose to be like that for a week. The cord doesn't show any cracking or noticable damage including by where the male plug meets the cord but it does look like the original 130,000 mile cord. I know places like NAPA sell the cords but where can I find the highest quality cord? Would an International dealer have a better quality cord? I thought about cutting the male plug off the original cord about 3" back from the plug and then rechecking for resistance. If I got a normal reading I could put a high quality plug on it. But I'm thinking it's the original Ford cord which isn't the best gauge to begin with and it has 130K on it. Should I just replace the whole cord regardless?

I know it maybe the block heater as well. But with it being -37 and me having two herniated disc's I really don't want to start crawling under the truck to do a resistance check on the heater itself if possible. I have big hands and I'm not sure I can get to it without removing the starter. Plus with only 130K on the truck it's unlikely it's the heater.

 

If I replace the whole cord am I going to be able to get my hands to the heater itself to replace the cord without removing the starter? With it being -37 for the next week I really don't want to pull the starter.

 

i would cut the cord end off and replace it with a 15 amp 120v cord cap.... usually the issuse is in the cord cap end.... change out the plug end first at this point it can get any worse i dont think.... worth a shot i still have the OG one on my 90 idi it works great i belive it is a 1500w element and if you pull an amp draw it should pull 12.5 amps

 

I cut the plug off and it was still open. I cut about 10" back from the plug and it's still open. I also found areas of the cord missing the protective outer insulation. So the cord and maybe the heater are pooched. How hard is it to get to the heater? Can you unplug it from underneath or does the starter likely have to come out? It's -40 so I'm REALLY hoping I can just unplug it and plug a new cord in.

 

The cord also unplugs at the heater, you may want to check that it's still plugged in.

You shouldn't have to drop the starter, there's quite a bit of room up there. IIRC when mine started leaking on the '84 I was able to remove it and install a freeze plug without dropping the starter.

Someone said Napa has the cord...

 

Hey, just found it on fee-bay:


http://www.ebay.com/itm/Ford-6-9-7-3-L-Diesel-83-94-Block-Heater-Cord-Only-F350-F250-E350-/110990874407?pt=Motors_Car_Truck_Parts_Accessories&hash=item19d7925727&vxp=mtr

 

Thanks C.E. Even though it's -40, tomorrow I will go out and remove the cord to determine which is the problem. Can you unplug it from under the truck?

I thought I read somewhere that Napa carries them but an International dealer would have a higher quality cord. I think someone said Ford wanted $120 and the International dealer wanted $40.

 

It should be relatively easy to access. I know that you can see it well, and it just plugs in to the heater. I bet it will feel like it's welded on there after 25 years or so, but you should be able to change the cord and leave the starter in place.

I would bet ford is selling you the whole heater assembly and not just a cord. I would also bet a cord from the parts store would be similar in quality to what came original.

 

I just installed a new cord from Napa, it is fine. Honestly it takes two minutes to install, just grab one from Napa and be done with it.

 

Unplug the cord and check the heater with your ohm meter. If should have a few ohms of resistance. If its open then your pretty much screwed you have to drop the coolant and the starter to replace.

 

I called NAPA today and they said they have one for $16. That seems pretty cheap. Is it really a good enough quality? The one on eBay was $35. I would think a good quality cord would be at least $25.

 

Dude, chill on the quality aspect. Everywhere you get it from, will likely be exactly the same..... Basically, its just a cord with a special end on it. Granted it might be a special insulation on the wire, but how much do you expect to pay for a short extension cord? Plus you've said before you're short on money. So get the cheap ones and invest the rest in some handwarmers.

ebay is ebay, sellers try to get as much as they can for whatever junk they happened across. Dealerships charge up the wazoo for anything.

Herniated disks or not, you need to get your *** under your truck and test for resistance at the heater itself. I know its freezing *** cold up there, but neither you, nor us can fix your truck sitting inside at the computer. If you only want to get under there once, get the $16 cord from Napa, pop it on there, and see what happens.

You'll want to bring a couple plastic zip ties with you to attach the cord to as you run it up to the front of the truck. Make sure you leave some slack between the engine and body to account for the engine movement.

 

You could unplug your old one and check continuity from end to end. You might be able to see something wrong with the other end.

 

I read in a previous thread here that the International dealers have a better quality cord. If I do something I do it right. Take your attitude and shove it.

 

I already removed the cord and tested the heater, Dude. I was asking if there were better cords than the NAPA one. I've worked on vehicles for over 25 years so I know MOST parts are made overseas nowadays. But there are exceptions to that. I wanted to double check before I put the new one on. Maybe you should chill and read a complete thread before giving an opinion?