random square body questions I would like some help with.

[crewcab higgy]

First
What is the best rout to put mechanical gauges in factory instrument cluster on late model squares?
Second
Will a faulty tank transfer valve keep the fuel pump in the auxiliary tank from powering?
Third
Will gmt400 headlights work in an 89 square? I would like to install a set of projector hid's but every thing I find is for gmt400 trucks
Fourth
Since retrofitting an r12 system is a hit or miss is there a good thread on a junkyard r134a swap?
Thanks for any help or leads to the right direction.

 

[DoubleDingo]

Those are beyond my knowledge and experience with these trucks, I'm sure someone around here can help.

 

[firebane]

There is no good route for gauges. This solely is dependant on the gauge and your family skills.

Regarding the ac no there will not be a junkyard swap as they will mostly likely be under pressure and still contain freon.

 

[CSFJ]

What's the issue with converting your ac to 134? Another California libtard law?

 

[chengny]

1. Don't install mechanical gauges in your dash. There is only one system that could be monitored by a gauge anyway - oil pressure. The normal, transducer style sender and electrically driven dash indicator set up are good - they have proven to be extremely reliable and accurate even after years of use.

Other than oil pressure, nothing else on your dash could be measured with a gauge.

I suppose you could try to install a remote mount type thermometer to monitor coolant temperature. But as above - regarding oil pressure, the factory setup for temperature indication has a good track record. The cost of an aftermarket remote reading thermometer and the hassle of mounting/connecting it, would not be worth the effort.

Since system voltage is the only other dash indicator (and can only be driven electrically) that is about it.

2. No it shouldn't . Power is to the pumps is control by (and supplied directly from) dash mounted select switch. When the switch is toggled from one tank to the other, fuel pump power supply is switched over to the selected tank. The power leads from the switch to the fuel pumps (gray & tan) are also used to stroke the Pollak valve. Depending on which tank is selected:

A. The valve rotates and changes the plumbing over to whichever pump is active .
B. In the control head, the leads for level indication are switched to the active tank.

If one of your fuel pumps does not start - when it's tank is selected on the dash - it could be:

1. A problem in the switch
2. A broken/disconnected/burnt power lead between the switch and tank
3. A non-functional pump

The schematic for late model, dual tanks - if you are interested:

You must be registered for see images attach

3. I am not familiar with any of this

4. I am not sure what you mean by this question. There is no need to retrofit any components when doing an R-12 to 134-a change over. The basic steps are:

1. Open the system and use compressed air to blow as much of the old oil out of the components as possible.

2. Install a new receiver/filter/dryer.

3. Reconnect the hoses.

4. Evacuate the system and recharge with 134-a. Use approximately 90% of the refrigerant charge spec's for R-12.

For a detailed procedure on a 134-a conversion, see post #3 here:

http://www.gmsquarebody.com/forum/showthread.php?t=9684&highlight=death

 

[crewcab higgy]

The reason I want aftermarket gauges is the oil gauge worked sporadically at best but not on off it would read 5psi all the way to 40psi when I hooked up my mechanical gauge up I had a constant 25psi at idle. My temp gauge despite good track record **** the bed on my last outing resulting in the current engine rebuild due to blown head gasket and broken a broken ring. So I figure since I gotta do 2 I might as well add a mini tach to the empty space and do the volt meter at the same time. Thanks for the help so far. Also with the retrofitting r12 to 134 the issue I have is its not as cold as the r12 was and not as cold as my new cars with 134 systems so my question is can a complete r134a system off a gmt400 or newer truck or suburban can easily be adapted to our trucks?

 

[CSFJ]

I don't think you'll have that much difference with 134 in a r12 system. I did an old '85 buick century years ago, and that thing damn near blew snowflakes out of the dash. As long as the cooling fins on the condenser are in good shape, what else do believe is different on the systems?

 

[crewcab higgy]

I don't think you'll have that much difference with 134 in a r12 system. I did an old '85 buick century years ago, and that thing damn near blew snowflakes out of the dash. As long as the cooling fins on the condenser are in good shape, what else do believe is different on the systems?

R134a systems have stronger compressors and larger a larger condenser. My experience with retrofitting to 134a was in my 79 camaro it was better than nothing but not good enough for me to justify they weight and hp loss so in the scrap bin it went. If the stock system in theses trucks is adequate for 134 use I'll try it.

Oh and one more question is there a good power tow mirror set up that will let me keep my wing window?

 

[CSFJ]

I know the last couple of years of the suburban had power mirrors available, but I've never seen a power tow mirror. I think some of the newer semi trucks have power mirrors if you wanted to retro fit them, but have never seen anything factory.

 

[silverscottsk10]

R 134 and r 12 use different hoses, oil, filling orifices, and filters
You cannot run 134a into an existing r 12 system as the line fittings are different sizes

 

[CSFJ]

R 134 and r 12 use different hoses, oil, filling orifices, and filters
You cannot run 134a into an existing r 12 system as the line fittings are different sizes

That's why they have adapter fittings that screw on over the original orifices. Just did this to my '88 silverado yesterday.

 

[highdesertrange]

as far as the gauges fix your stock gauges, as chengny pointed out they are very reliable. btw your gauge didn't cause your head gasket to blow if your saying your gauge was reading normal and you were actually overheating, I would say ok, but you didn't notice anything was off?
#2 refer to chengny again.
#3 you will get better lighting with cbie housings and halogen bulbs. I know you won't look as cool but they will blow the hid's away as far as actually being able to see.
#4 the only problem you should have after the 134 conversion is when you are idling, install a fan on the condenser and this will be sovled. you can wire the fan to come on with the ac or manually turn it on when you are in stop and go traffic.
highdesertranger

 

[crewcab higgy]

The temp gauge stuck at 210. My buddy behind called me and told me to pull over and sure enough the coolent in the over flow was boiling. Checked my gauge and yep 210 when I tapped on the dash it pegged high. I guess what acutely caused the issue is the water pump gasket failed at the block, I guess poor craftsmanship of the previous owner.