Last winter I had a couple of things happen , when it was colder than my exwife's ***** in a brass bra my tack , high beam indicator and heat didn't work, well after driving 20 miles the tack and high beam indicator started working again, but no heat, this year I have actually too much heat ( not bitching about that ) BUT my tack stopped this morning, high beam indicator is working fine, its a 93 and i'm happy as hell the heat is back, but why did the tack quit? does it run through that computer? or is it just wired from the col like the old cars were?

 

It's off the computer.

It could be almost anything; bad connector at the ECU, bad connector at the bulkhead fitting, bad connector at the gauge cluster, bad tach board, bad connection to the tach board, bad gauge, and bad ECU.

(I'd bet more the bad connection to the tach board; but that's just a WAG from here.)

RwP

 

I had the same thing happen on my '93. The tach module thingy on the back of the cluster was bad.

I got a parts truck with a tested working cluster if you need it.

 

Thanks for the input guys, I'd lean towards a bad part behind the cluster, I've spend the past YEAR redoing every wire in that truck just to make sure everything worked, and to fix what mr mud truck builder did to it before I traded for it, and I hope its not the computer because its bad enough the check engine light wont come of no matter what, kinda a good thing I remember how to work on vehicles lol, but the computer doesn't do anything except run the fuel injector, the overdrive module TSS, and iac and o2 sensors nothing else like tamp sensor or oil sensor is connector anymore, and teh damn truck STILL gets 16 miles to a gallon, not bad for a 3" suspension and 3" body lift on 31's instead of 205's huh?

 

So you've got an aftermarket ignition system going?

That could be your CEL then; what codes does it generate on the key dance?

RwP

 

No its not aftermarket, its Frankenstein from the guy that had it before me, he was building a mud buggy for his girlfriend ( so he says) and they broke up so after waiting two years he decides to get rid of it, the entire electrical system is a electric nightmare, I had to bypass everything except the fuel injection system, so thankfully I had an old Holley mechanical throttle body that fit, and works better than the other one that takes computer input, until I can get the wires figured out under the dash board and under the hood. The only reason I trade in the first place is I had an 88 Dakota I was given out of a friends back yard that had sat three years and was buried up to the rims, he said if I could get it to start it was mine well after a battery I had the title in hand, and it ran for years with no issues at all mechanically electrically or structurally, so I wanted another one.
I WILL fix this one too, even if I have to install a aftermarket tack that runs off the coil

 

Before I tackled the tach too much; a) grab a copy of the factory service manual for your truck; b) fix it back to OEM specs, and then c) worry about the tach. The coil is driven off the ECU also; if it's been butchered in the wiring, you may have an intermittent wiring problem between the ECU and the bulkhead fitting.

Yah, my 1988 is over 391,000 miles now and still rolling.

RwP

 

Yea, the only reason I sold my 88 was the height sensing valve that was "no longer made" or "available" in Va Beach and it was illegal to modify a brake system in any way, 3 months after I sold it they changed the law so that I could have removed it and put in a "T" fitting, had I known that I would still be driving that 8 foot bed little monster cause the VA St insp was 6 months away

 

*facepalms at the VA law* The Law Is An Idiot.

Too bad you can't reclaim it!

Although, truth be told, the Magnum is a better motor for day to day operation than the LA was.

RwP

 

Yep and your facepalm, is yet ANOTHER reason I abandoned Virginia Beach, I'd tell y'all about the house problems I had to deal with for 25 years but there isn't enough coffee in Duck Thru to keep me awake that long
A guy at my work said it might be the speed sense solenoid, which is either combined with the back up light switch or inside the trans, or on the transfer case, I haven't checked yet because (1) its colder than my exwifes ***** in a brass bra outside (2) its Friday since I'm a state worker I have no where to go and (3) it'll be my luck its right next to the OD switch in the trans