Mrfarb’s 2009 M1151a1 build thread

[mrfarb]

Figured I’d start a thread about my 1151a1 to keep all my junk in one place, easier to find anyway. First thread involved installing glow plugs:

Glow plug day for my 1151a1 rev

Yeah, I thought I’ll go out this morning and change the glow plugs out, shouldn’t be too difficult. No. Just no on the right side. I feel like this is what happens when you keep adding more and more features but don’t reengineer the simple basic maintenance items. Pretty much seems like I have...

www.steelsoldiers.com

Today, it’s time to recharge the a/c to test it. When I got the truck the a/c was non op - turned out the hose that connects front and rear evaporators had was laying on the exhaust and had a hole in it. Replaced that hose and the a/c dryer at the back.
Full admission, I’m not an a/c tech, but I’m handy and harbor freight is close by. I have an a/c tech to call though, which helps. So far so good! Hope there aren’t any other leaks. Going to keep vacuuming it for about 45 minutes.

 

[mrfarb]

First issue - condenser fans on right rear aren’t coming on, left rear are working.
Thought someone might be able to explain this - factory a/c front and rear. Just charging it, left rear cond fans run normal, right rear are not running - looked at wiring diagram and both are powered from the same relay. Has this happened before? Had to replace right rear fan assy, tested 437b and no power:

Edit - I have .24 volts at each 437b and 437c, so I’m guessing the relay isn’t good, but still not sure how I get power to left rear cond fans and not right rear.

 

[Mogman]

If both sets of fans are powered by the same relay and you have power to one but not the other than you must have a wiring issue.

 

[Mogman]

If you can post the schematic you are using so we can all see the same thing.

 

[mrfarb]

This is from an older thread:

 

[Mogman]

The power for the left side cond fans gets its power from the rear evap, not the rear cond relay, follow 416A

 

[Mogman]

Do you have a schematic of the rear evap?
The first thing I would do is see if there is power at 720A at the rear evap, should be hot all the time.

 

[mrfarb]

Of course, I see that now. No other schematics that I can find, but if the rear evap powers the left fans which are working, there must be a 437 wire at the front evap. I notice it’s missing from this schematic.

 

[Mogman]

No 437 comes from the cond relay, follow the numbers, 436 controls the relay coming from the low pressure switch.

 

[mrfarb]

I see, I need to pay better attention - time to give it a rest until tomorrow. Now that you say that I see - I need to confirm power is coming in to the relay at 445a and move backward from there. Thanks for the help.

 

[Mogman]

The power for the rear evap. and left cond. come from the other 30A breaker in the battery box,,, wire #720A, nothing to do with any of the 445(X) circuit at all.

 

[mrfarb]

The power for the rear evap. and left cond. come from the other 30A breaker in the battery box,,, wire #720A, nothing to do with any of the 445(X) circuit at all.

OK, bit of confusion on my part or yours - rear evap works perfectly, left cond fans work. It’s the right side condenser fan set that is inoperative.