20 Most Recent 1986 GMC C1500 Questions & Answers

Hello Chris
Here is a diagram for you. hope it is large enough as we are not allowed much space here to post pictures.

1986 GMC C1500 | Answered on Jul 22, 2019

I found window motor connector for your vehicle at rockauto.com, it was two wires, so that is up and down, correct? Sorry, I don't have wiring diagram for your vehicle year? The closest I could get was 1990 for gmc pickup. If the wire colors match up, it may work?
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1986 GMC C1500 | Answered on Feb 14, 2018

You may have a leak vacuum or part. Check hoses and then fittings. A switch is changing or temp sensor maybe be an issue also. Check engine codes also

1986 GMC C1500 | Answered on Dec 29, 2017

fast idle speed screw, works off the fast idle cam which the choke adjustment sets, it works together by linkages. This is the raised idle speed setting you need to keep a cold engine running. First you set the idle speed by the idle speed screw with engine at normal operating temperature. Then you set the linkage up so the cam is on a raised step, throttle will be held on that raised step. then you can turn the idle speed screw to get idle at about 1500-1800 rpm. Now when you start engine cold, choke will set the fast idle cam on that raised step- when engine starts and runs it should be running at your fast idle setting. That's how it supposed to work, you just have to get everything adjusted right. I hate carburetors, they never stay adjusted right. Considering their complexity and small mechanical parts, no wonder.

1986 GMC C1500 | Answered on Dec 24, 2013

Most shifts can be done on the fly by moving the selector breaking the power by lift ting the foot of the gas for a sec.. To really save on gas have locking hubs fitted to the front wheels and in the unlock position the vehicle is like a 2 wheel drive vehicle. Check the operators manual or down load it from the GHM web site.

1986 GMC C1500 | Answered on Sep 23, 2013

Why would you tell us that or be confused ?

You obviously were given the wrong parts

Take them back & take your old ones to show
the counter people

1986 GMC C1500 | Answered on Oct 03, 2012

if all the gauges are inop look for a bad fuse if there ok remove the cluster and look for a bad connection

1986 GMC C1500 | Answered on Apr 16, 2012

i have a 1990 jimmy and it should b the same but follow the fuel tube along the undercarage and u should come to the filter and then all u do is unbolt the clamp and unbolt the filter and in goes the new one..

i have a 1986 S-15 JIMMY and found the fuel filter on the engine block. Located below the power steering pump, on drivers side.

1986 GMC C1500 | Answered on Mar 05, 2012

the brake lights and the rear turn signals should be the same bulb check the bulbs to make sure they are not blown does your third brake light work if all brake light are out and the bulbs are good check the brake light switch on the brake pedal

1986 GMC C1500 | Answered on Nov 04, 2011

This works with the 5 prong module on an HEI ignition system with the coil that is mounted on the top of dist. The wires that come out of the back of the dist go to a spark controll module under the dash and they are junk. There is a conector on the wiring harness about 5" from the dist unplug that conector and run a jumper wire from the green wire to the black wire on the dist side and make sure you tape up all wires on dist side to keep them from grounding out. On the other side of the dist where your 12V goes in (batt conection) there are to wires piggybacked on top of each other disconect them from dis and plug only the pink 1 into dist at the batt conection. Where the wires on the back of dist run into firewall there should be a vacume line disconect and plug on engine compartment side. Thats how you do the bypass and the spark control module can be removed from under the dash if you want to but its not hurting anything to leave it there. BEFORE YOU DO ANYTHING MAKE SURE YOU DISCONECT THE BATTERY. When all this is done you mite have to advance your timing 8-15 degrees. I had to advance mine 12 degrees. let me no if you have any problems. kyle yeo

1986 GMC C1500 | Answered on Apr 15, 2011

If it is a 4 speed, dash indication has 2 D's and 2 and 1 it is a 700R4. If it just has D,2,1 It has a TH400

1986 GMC C1500 | Answered on Mar 26, 2011

have u replaced fuel filter?

1986 GMC C1500 | Answered on Jan 25, 2011

This can be either an igintion module or a igintion pickup (Located inside the distributor) problem. To determine which one you will need to run a fault code using the Data Link connector under the dash in front of the driver. To do this test and see a list of codes and what they mean please go to the web link below.

1986 GMC C1500 | Answered on Jan 04, 2011

If you look under the hood you will see the heater inlet/outlet hoses going through the firewall. The heater core is located on the opposite side of the firewall where those hoses are connected. You can fix this on your own if you have lots of patience and determination. The hard part is just getting to the core. You must remove enough of the dash to allow access to the core. Some parts may just clip on and others are held on with screws. Take photos as you go along so you can remember how to reinstall everything. This is a very labor intensive job and that is why this is an expensive repair if you have someone do it for you. The part is cheap, the labor is not. If you do it, then this is a good time to service the cooling system. Drain, flush, replace thermostat, and fill it up with a 50/50 mix of antifreeze and distilled water. Replace any hose that is suspect. Good luck.

1986 GMC C1500 | Answered on Oct 30, 2010

Probably the choke pull off is not working, and the choke is flooding the engine

1986 GMC C1500 | Answered on Oct 15, 2010

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