Deere Mack

Maybe the low coolant sensor is bad in the recovery tank. Had that problem with mine...it would come on in-frequently and show engine shutdown/electronic malfunction lights, then ended up with it coming on every time I started the truck and eventually went off after it ran for a while. The sensor is about $12 and took 5 seconds to change.

The sensor was a easy fix, but the cost was somewhat different than you had mentioned. My cost was $38 and that was with a good ole boy discount. What cost out the yang was an damaged two prong electrical conector that I wanted to replace. It was about $30........I'll never do that again, I'll be splicing and patching like the last guy, just with a little more pride.

Finally got back to this project. The low coolant reservoir sensor was the problem with the Engine shutdown and the electrical malfunction lights. Let me say I appreciate everyones help!

Now my fan after replacing the solenoid runs continuously. I plumbed it the same way so go figure. At least I don't have buzzers and lights going off and although not economical my fan does work, just all the time. I'll figure it all out one of these days.

I have the factory wiring diagram book for your truck but it just dont show the fan solinoid very good at all. I was trying to find where the ground wire returned to the ECM. I do know that it gets it's power from fuse #10 in the fuse panel.

Your are one helpful man and I appreciate it all. It is definitely a maze of wiring. I would like to have all new wiring and fuse panel someday. There has been to much patch work here and there in my wiring before I got it. I'm pretty sure the coolant steam bath it got has shorted or is shorting something out somewhere. Do you know of anyone that specializes in replacement wiring harness or is this something I'll have to turn to Mack for?

The very back sensor that faces the firewall goes to the ECM, the one that faces out toward the hood goes only to the guage on the dash. Got snowed in today and am not at work so I cant look at the wiring diagram, I'll see what I can find tommorrow. Have you shot air directly to the fan clutch to see if it will engage or disengage( however it is set up)? I think a fuse in the fuse panel sends 12 volts to the solenoid all the time andcomes back and then grounds inside the ECM. The ECM will make the ground when it see's high R12 A/C head pressure, high water temp or high intake temp to engage the fan.

Ok, I think I might have told you wrong about my solenoid. If I unplug the solenoid it allows the fan to run continuously, so it takes power to the solenoid to turn it off, which evidently its getting. So I'm not getting the ground in the ECM to kill power and let fan run at high temp. This dont sound good, ECM problems? I haven't had a chance to check for volts (which now I know the solenoid is getting), the truck is still at a job site.

Your year model is tricky because it could be either a VMAC1 or VMAC2 (engine electronics), all fuses and ECM's are in the cab on both models( unlike the ETECH style engine). VMAC1 had nothing to do with engine fan control, the fan control was kinda added on and not really part of the VMAC system.It had it's own 2 prong sending unit ontop of the water manifold, the degrees stamped on the sensor tells what temp it will engage(usually around 205) . When VMAC2 came out, it controlled the fan on/off. It used the existing temp sensor for the ECM to decide when to turn on the fan. The dealer could also raise and lower the engagement temp with a prolink computer. Both systems still used the same fan clutch and solinoid. Which light is coming on red shutdown or yellow electronic malfunction? If it's both it's the low water sensor or wiring to the sensor or really has low coolant. Is your metal radiator cap on the radiator itself or on an overflow/surge tank in the fire wall? Forgot to mention, love your truck, Alxe forward CH's are my faavorite! One of the best ones I ever drove was a 1990 with a E-7 400hp manual fuel pump, the old man that taught me all about Macks cranked the rpms and fuel to it and it was a screamer. The second best was a 1996 with a E-7 454hp it was awesome as well.

Thanks for the info and comments Mack. Mine has the E7-427 and she'll pull around my JD 750C II Dozer like it isn't even back there.

I'm goning to replace the water level sensor just to be able and rule it out on the Engine shutdown and Electrical Malfunction ligts. My fan takes air to engage it and thats the problem with the fan not getting power to open solinoid. Strangely enought this all happened at the same time, blew the manifold hose and saturated engine compartment and been having both problems since. Where exactly would the sensor on the manifold be for the solenoid? I was told it was at the very rear, and replaced that one with no luck. I have the overflow/surge tank on the fire wall.

Ok, I've checked for any fuses for the fan soleniod in the engine compartment, results-negative(not to say there isn't). I did put a wire tracer on solenoid hook up and ended up at a air conditioner line on the oposite side of the radiator and another sensor. So, I got on BMT and found a similar topic with fan failure and someone said that the sensor was part of the fan operation and was know to go bad. Anyone have any input on this? Always appreciated.

your a lucky man to have puchased a pre emission truck. pay close attention to anything to do with egr or pfd or uria injection, because one of these day's you will want to trade if you go 03 or newer do plenty of research, and then dont do it, keep rebuilding your 98 till you retire

just remember 03,04,05, are not worth the rubber they are rolling on!

Thats the plan man! I'm a very conservative operator, but I don't like to let things go either. When its time I plan on doing a complete rebuild on my CH. I do find the EGR business very interesting, especially with global warming and all.......HA!

every thing is fine so far. im just a little scared to start monkeying with it. (blocking egr)

If it aint broke, dont fix it! But, I would stay on top of the fix or bypass for future reference. What year did they start using this?

that is a good lookin ch, i see you are new to this forum, ive only been here about 3 months, but have learned every body has good input on problems, but when fjh or mackpro68, makes a sugestion, take it serious, they are very sharp on this internet machanic stuff.

every body on here has helped me. good luck with your fan prob. im sure it will be something cheap and simple. haha, nothing about trucks cheap or simple.

I appreciate your comments bigen, you've got a fine looking truck yourself. Nice color!

My bad, I guess I didn't pick up on your problem being the fan.

I always thought that whenever something was wrong with the fan it would end up being stuck on. It not engaging...not good.

Its all good, the water level sensor could very well be my waring light problem (same symptoms) and the fan all together another problem. I just got the truck about a year ago and its my first big rig, so I'm learing alot fast! As of now I've got the selonoid bypassed and the fan runs all the time, but the problem still exists. I hope to get this big boy in top shape one day!

I appreciate everyones help. Would the coolant sensor etc. keep the solenoid from engaging the fan? My truck takes air to engage the fan, and the problem is the solenoid dosen't receive power to open up when the temp gets up. Plus the engine shutdown and electrical malfunction lights randomly go on and off.

I sure hope so, driving me crazy. I'll look first chance I get and post update. Thanks for the help!

coolant level?

Check fuse?

Coolant-good, fuse-have not been able to locate a specific fuse that allows the horton air fan to work? This all started when i blew the small hose between the water manifolds. Lost alot of fluid and steamed up the engine pretty good. But that was a month ago and should be good and dry by now?

Getting the dash waring lights, everything else is working fine, runs good etc. I have changed the cylinoid on side or radiator, changed heat sensor at rear of manifold. Still no luck. I would appreciate any help. I also look forward to using this forum and more than likely becoming very active within it.