Someone gave me a 87 s10 blazer some time ago. Today out of the blue the digital gauges and the ac/heat died. I checked the fuses and they are fine. I have been racking my brain out all day and cant come up with anything to fix it.

Is there anyone out there with any ideas? Is there another fusebox I dont know about? Im ready to drive it into a lake....lol

Also here is another question. I was told that the motor was a 2.6, but when I installed a alt. last week the 2.6 alt did not have the same bracket, the 4.3 on the other hand did. I didnt see any marks anywhere to identify the motor. Did I miss something.

Thanks in advance for everyones help.

 

Nobody has any ideas?

 

Slow down there man... No need to bump a thread after only 6 hours... We all have lives too...

Anyway, to your problem... This sound a lot like the ignition module problems that seem to plague the newer trucks, but I don't know if an '87 even has such a module.

And I think you mean 2.8L. Other than having the 2.8L in a previous vehicle ('85 S10) a long time ago. It is possible that they changed the alternator mounting to match that used on the 350 and the new 4.3L.

 

I meant 2.8 Im sorry. and sorry for bumping the post so soon. I have been banging my head all day trying to come up with a solution to this problem. Whats puzzling me is that the A/C and Gauges went out at the same time. They were fine. and then 20 minutes later we started the car and they were dead.

 

damn after 2 months there is nobody with any ideas to this? I had it at the mechanic and he said it was the dash that was causing it all to not work. Something about the dash controling the ac/heat. But he could not find a replacement dash. Funny thing is I did, but the only issue is that my 87 has a 89 or newer digital cluster ( they didnt have the digital gauges in the 87 model) that someone must have installed. But the company that repairs these gauges tells me that the dash has nothing to do with the ac/heat not working and to check the fuses...lmao.

Did I mention I have replaced every fuse in that truck and nothing is still working? So really if anyone has any ideas I would love to hear them right about now.

 

So there is not one person here that can give me any ideas? I was really hoping to get some help here.

 

What on your ac/heat stopped working? If it is your blower have you checked power to the blower? How about the switch, relay, resistor? If your selectordoes not work, have you checked the vacuum systems? For your dash have you checked power, and grounds to the dash? After 2 months have you just waited for someone here to respond? Those dashes are very prone to fail, you can find almost a full page of rebuilt ones on E-BAY. But a little more info than it just died would be very helpful here. Korey.

 

I did post additional info. The blazer was at the mechanic last week. He tells me that that AC/Heat is not working (Blowing) becuase its all connected to the dash. Also that he cannot find a dash that will fit it. This part is easy. Its a 1987 and they didnt have a digital cluster in 87 . I dont know who or when the digital cluster was put it.It had to have came out of something 89 and up. I know I can get the replacement from Mr. Whizard I just need to pull it out

The concern is the dash blacked out and the ac/heat stopped blowing at the same time. It all was working, then the next time I started the blazer it did not work . Radio and all acc are working. So here are the questions I have.

1. Is there something that does control the Dash, Heat, And AC ?
2. Is there something that the digital dash could be hooked up to that caused it? Seeing is though it went from a analog to digital gauges. Maybe they have a wire running to something that controls AC/Heat.

I have checked all the fuses. I imagine the mechanic checked everything. But maybe not. What do I need to be looking for to see if the relays or resistor is no good?

 

Now that we know when you say that your heat/ac is not working is actually the blower not blowing I can help a little more. Believe it or not they are not the same, when a customer tells me there heat is not working, that means there is no heat, when the ac is not working there is no cold air, and when the blower is not working that means no airflow, and last, but not least, when they say the mode selector won't change that is all together another system. So you see there are atleast4 systems within the heat/ ac system. So I was not trying to be an *** but I needed to know exactly what system was not working. So now that I said that, unless when they put the digital dash in they tapped into other wiring, the two problems should not be linked. I just looked at the wiring diagram, and they are not on a common circuit. To check the relay and the resistor, you will need a volt meter and a wiring diagram, then start checking the powers and grounds. It is really pretty simple, thoughI am leaning towards a bad switch ormotor because the relay controls high, and the resistor controls lower speeds, and for them both to go at the same time is really rare. I wish I knew how to get the wiring diagrams I have to download to you, but I think because I use a subscription service for my info, I am not able to copy it. So hopefully somone will download a copy for you or maybe you have one already. Good luck. Korey

 

Thanks a bunch.

I also got a reply on another board and they are thinking about the same. He said he has heard of people doing dash conversions and cutting the harness while tapping into things they should not to get everything on the digital cluster functioning. His advice was to get a 87 gauge cluster and harness and that for some strange reason they may have tapped into the AC/Heat.

And if anyone does have a wiring diagram it would be of alot of help. For future reference I will also take photos of the harness and everything to show everyone whats going on .

Thanks again