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110 Heated Windscreen

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14K views 30 replies 9 participants last post by  JimC 
#1 · (Edited)
Based on a previously posted suggestion from Mike at ECR, I purchased a heated windscreen from RN. The part number is RRC7310. This is not the stock replacement, but the military version which is less expensive ($200+ less IIRC). Having just received the windscreen, I noticed the electrical connections were different than the stock windscreen (i.e. the terminals are located on the bottom rather than the top). To make sure I understood what all of the differences are, I asked ECR for an explanation. They were kind enough to provide the following detailed response which I hope will help others who might head down this path:

"The military heated screen RRC7310 works better and is much cheaper than the stock NAS screen (BTR5161 is the old part #), but the stock wiring in an NAS 110 will not support the RRC7310 screen. It draws a ton more power. You'll need to upgrade the power sources and the power source relay and fuses to be able to take the amps the military screen pulls or it will melt down your stock wiring. You'll also need to relocate the power and ground wires to the dash and not the headliner. If you are looking for a no hassle easy install... get the standard NAS 110 screen. If you want a screen that is cheaper to replace and works a little better do the upgrades to make the RRC7310 work.

I just went over all the change over issues with Mark at RN, so give him a shout and he can set you up with the parts needed. RN sold us these screens in the past as direct replacements, but as we have done a number of installs now we have found the issues that RN was not aware of. They now know of the issues and are said to be making changes to their ordering/ sales team."
 
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#4 ·
Overlander said:
That's worthy of a sticky. Thanks Ryan. I know you don't need it in Escondido. Tahoe perhaps?
Mark - I do a fair amount of climbing trips to Utah/Colorado so the heated windscreen is really nice to have. My current windshield decided to crack while the truck was sitting around waiting for the 2.8 so that's why I need to replace it. I always wished it had more power so I'm looking forward to getting this military version installed.
 
#5 · (Edited)
Ryan. After my original windscreen cracked, I purchased the RRC7310 after reading this thread. Was assembling the dash today and noticed that even after the dash top is installed you still can see the terminals.
Is this correct? Is there a way to hide this?
Did you upgrade your wiring like ECR suggested?

Thanks,

Ze
 

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#6 ·
Yup, looks just like mine. Don't know if your TD5 bulkhead is any different from mine, but I didn't see any way of routing those through the sheetmetal. There's a trough that's right behind the dash, and I'm planning on running my wires there. You'll still see the windscreen flex cable looping down into the trough behind the dash, but it will be visible to some degree no matter what you do. I'm actually in the process of doing this as I'm cleaning up a bunch of electrical stuff. If I have the truck running in another week or so, maybe I can stop by and we can compare notes.
 
#7 ·
Ryan,

I think you just saved me from going crazy. When my 110 windshield was replaced by the insurance company, I was re-assured they got the right one when the new one had the correct connector tabs and markings. But when I went to use it, it blew the fuse after a second or so. I researched the schematic and wiring but in all cases when both sides of the glass were hooked in it would blow a fuse. But when only the drivers or passengers side was connected, it worked fine.
I wondered if it might be that it had a different current draw but thought that was pretty unlikely the mfgr would change the resistance of the glass wiring. But, your experience proves it can be different!
I think mine is not the military version though, as it fits correctly with the connector tabs at the top. Are you aware of any glass markings that would indicate the LR P/N or resistance values, etc?

I hate to think I have to mod the wiring to make it work but if I have to....

Cheers,
Dennis Yard
San Diego
 
#8 ·
RyanS said:
Yup, looks just like mine. Don't know if your TD5 bulkhead is any different from mine, but I didn't see any way of routing those through the sheetmetal. There's a trough that's right behind the dash, and I'm planning on running my wires there. You'll still see the windscreen flex cable looping down into the trough behind the dash, but it will be visible to some degree no matter what you do. I'm actually in the process of doing this as I'm cleaning up a bunch of electrical stuff. If I have the truck running in another week or so, maybe I can stop by and we can compare notes.

Sounds good. I'll be up at Nick's Friday.
 
#9 ·
Dennis - Why don't you just measure the current draw, and then you'll know for sure. I don't believe there are different versions of the stock windscreen. Once I have mine wired (hopefully this weekend), I'll measure the current just to confirm that my wire sizes and fusing are correct. If you have access to a clamp-on DC ammeter, it's a really easy thing to do.

Ze - As I mentioned above, I'll be wiring this weekend so maybe I can stop by next week sometime. Send me an E-mail when you're available.
 
#10 ·
Ryan,

Thanksf for the offer of measuring the current. I don't have a clamp-on meter, so will have to check with Nick or other club source to try that route. I did measure resistance of the windshield sections but without comparison numbers its hard to tell how or if my screen differs.

I would appreciate hearing what your current measurements are.
 
#11 ·
Dennis - Since I have the military windscreen, its current draw won't mean anything relative to your stock windscreen (other than confirming that it does indeed pull more current like it's suppose to). The stock windscreen is fused at 20A so it would be interesting to see how much current each half of your windscreen is drawing. The stock wiring is very simple as there's just a single hot lead from relay going to the center of the windscreen, and a ground that branches to each side. So really not much to troubleshoot. You're welcome to stop by sometime if you want to measure the current here.
 
#12 ·
I got the military windscreen wired up and working. It draws about 23A total with that about equally split on both sides (11.5A each half). So yes, the wiring/relay/fuse should definitely be upgraded for this windscreen. I used 12AWG wire, a 70A relay, and a 30A fuse.

By comparison, the stock 110 heated windscreen is fused at 20A so I'd guess it draws around 15A. Also checked the rear window defroster, and it pulls 6.7A.
 
#13 ·
Dennis, there is more than one heated screen...

... (that is factory / non-military) and unfortunately, I don't know how to tell which is the right one. I found this out when I had mine replaced at the dealer. They ordered it up installed it and it blew fuses almost immediately each time I used it. They figured out that there was another specification, so they ordered that one, installed it and it worked fine.

I can't really examine it because I've since sold the 110 to another member here and sent him all of the paperwork as well.

In any case, I'd guess that you have the wrong screen.

Devin
 
#14 · (Edited)
Devin,

Thanks for the confirmation that there is more than one non-military version as well. I will measure current and resistance on this one over the weekend and post the results. Since the insurance co. replaced this one some time ago, I don't think I can get it replaced by them.

I'm wondering if I can put a ballasting resistor in the line to cut the current draw, even if it reduces the screen defrosting effectivness. A large ceramic might be the ticket to increase resistance and decrease current. I guess its workability would end up depending on how much heat it has to sink.

I am thinking of this route so I can stay with the original wiring, fuse and relay. I really hate to muck the wiring on a solid truck that the PO have kept pretty stock.
 
#15 ·
Devin - Interesting info.

Dennis - Can you find out what PN was used by your insurance company (or whoever did the actual replacement)? That would help others avoid this problem in the future.

From my parts catalogs, I find the following info:

NAS 110, Tinted Heated Windscreen = PN BTR5161
ROW 110 (1990-1998), Tinted Heated Windscreen = PN CMB000410
ROW 110 (1990-1998), Clear Tinted Windscreen = PN CMB000420

Don't have anything more current so don't know if 1999+ use a different windscreen as well.
 
#16 ·
Ryan and Devin,

I was able to do more measurements over the weekend, as follows:
Driver's side resistance = 1.1 ohms using 200 ohm scale
Passenger's side resistance = 1.0 ohms " "
Driver's side current at approx. 14 V = 13.3 Amps using Fluke clampon digital meter
Passenger's side current at approx. 14 V = 14.0 Amps " "
Combined current draw for both sides = 26.6 Amps " "

So we have conclusively proved that the new windshield draws more current than the original. It also shows why I can power one side or the other but not both through the 20AM fused circuit.

I have not been able to find any info on the replacement windsheild's P/N so far. The only markings are XXX Triplex, Laminated, DOT 49 M2 AS1

I still would like to measure resistances in Ze's old windshield as a comparison.

Now its off to figure out to what to do about the actual current draw.

Dennis
 
#17 ·
Dennis - The main limitation in your setup for running the higher amperage is the power wiring and maybe the relay (I think the stock relay is 40A so you could get by with this). So it really isn't too big a deal to modify it. The biggest hassle will probably be removing the fascia (without breaking plastic bits) to get at the relay which is behind the fascia on the passenger side. I went to a D90 style dash a while ago so I didn't have to deal with the fascia.

Here's what you need to do:

1. Remove fascia and locate the relay which is near the timer for the circuit.
2. Run new power wire (12 AWG min) fused at 30A, and terminate at relay pin 87.
3. Run new power wire (12 AWG min) from relay pin 30 to center windscreen terminal.
4. Run new ground wire (14 AWG min) to the two windscreen side terminals.
4. If you replaced the relay, transfer the control wires from the old relay (pins 85 and 86) to the new relay.
5. Test and then close everything up.

The main thing you'll need (other than wire and an inline fuse) are crimp disconnect terminals that plug into the relay socket. This will allow you to terminate the new wires in the socket. I got some with the new relay/socket I installed so if you don't go that route, you'll need to source some. If you're careful in removing the control wires from the old relay sockets, you can just plug those into the new socket.
 
#21 ·
surf110 said:
Was assembling the dash today and noticed that even after the dash top is installed you still can see the terminals.
Is this correct? Is there a way to hide this?

Ze
Even the latest 2009 rovers you can see this wire. one thing the factory does do, is slip over a piece of black rubber coating to hide the gold coloured braid (i just used electrical tape) to "take your eye away from it" if you know what i mean.
 
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