2wd fuse panel in 4wd

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Need15

Junior Member
Joined
Mar 4, 2021
Posts
26
Reaction score
32
Location
Canada
First Name
Brad
Truck Year
1982
Truck Model
K10
Engine Size
350
Just curious if there was any difference from a 2wd fuse panel to a 4wd panel besides not having the the ground wire and the pink/ black wire that ran to the transfer case to light the 4wd indicator on the gauges. Both trucks are 79's.
 

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
2,338
Reaction score
3,569
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
I’m not all that familiar with the older glass tube style fuse boxes, but for the most part with the exception of fuse boxes for trucks with gauges or idiot lights, they are basically the same. The optional equipment a truck might have had its own separate harness that plugs into the fuse box.

I’m guessing a 4WD truck would have a seperste harness for the transfer case/ 4x4 dash lamp.
 

Strick

Full Access Member
Joined
Nov 25, 2020
Posts
1,105
Reaction score
2,663
Location
Dunn, NC
First Name
Harold
Truck Year
1979
Truck Model
C20 Crew
Engine Size
350
I had to replace the fuse box on my 85 D30 (CUCV). They have a 40 amp fuse for the headlights that likes to melt. Typically the GM trucks don't have this fuse but the CUCV's do. They have a bunch of more junk because of the black-out features too. Anyway, I sourced a box from a 2wd C10 at the local boneyard. It was labeled differently but was set up the same or very similar. It took several hours to push out the spades from the old unit(s) and configure the wires into the replacement box. My advice is to be very patient. If you're over 6 feet (high or round) I would also recommend pulling the seat out as this will help with giving you room to move around.

Strickland
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Just curious if there was any difference from a 2wd fuse panel to a 4wd panel besides not having the the ground wire and the pink/ black wire that ran to the transfer case to light the 4wd indicator on the gauges. Both trucks are 79's.
Both 79s should have plastic fuses yes? In your case, I would say what trims and what GVW are both boxes from
You must be registered for see images attach

heres my 1980, k25(4x4 3/4 ton) gmc, with pretty basic optioning and some fuses/flashers removed at this picture. but the letters are good and i would guess its the same to a 79
 

Need15

Junior Member
Joined
Mar 4, 2021
Posts
26
Reaction score
32
Location
Canada
First Name
Brad
Truck Year
1982
Truck Model
K10
Engine Size
350
Both 79s should have plastic fuses yes? In your case, I would say what trims and what GVW are both boxes from
You must be registered for see images attach

heres my 1980, k25(4x4 3/4 ton) gmc, with pretty basic optioning and some fuses/flashers removed at this picture. but the letters are good and i would guess its the same to a 79
The 4x4 truck has no fuse panel so I have a 2wd parts truck that I took the whole wiring harness out of. They are both 79's but are glass fuses and not ATO style fuses. I think it should work, don't see any problems. Just gonna have to add the wires in for the 4x4 which won't be a big deal. Thanks forlorn the replies
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
The 4x4 truck has no fuse panel so I have a 2wd parts truck that I took the whole wiring harness out of. They are both 79's but are glass fuses and not ATO style fuses. I think it should work, don't see any problems. Just gonna have to add the wires in for the 4x4 which won't be a big deal. Thanks forlorn the replies
The 1979 model year had plastic fuses. What does the panel look like? The 1978 model year had the most glass fuses and should be fine for your truck if it’s stock and not loaded with a ton of features. You may need to wire things differently. Fortunately the 1978 and 1979 aren’t too different electrically so it should be not too painful. The 1979 fuse box was like mine shown above.
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,017
Reaction score
1,808
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
BLUF - in that timeframe I think the fuse panels for 2WD and 4WD were identical.

In ‘79 they were still using only the NP203 and NP205, and I don’t think there was any 4WD light in the dash. I know my ‘75 K25 has no dash light for 4WD.
 

CheemsK1500

Full Access Member
Joined
Jun 3, 2022
Posts
747
Reaction score
1,284
Location
Texas
First Name
Paul
Truck Year
1984
Truck Model
K1500
Engine Size
305
I assume they'd be the same, though there is a quite a bit of difference between the fuse panel on my '84 K1500 and '85 C10. I haven't looked at enough round eye squares to know if they'd be any different. With that said, if you're rewiring everything, you can use any fuse panel you want as long as there is enough slots for your application.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
BLUF - in that timeframe I think the fuse panels for 2WD and 4WD were identical.

In ‘79 they were still using only the NP203 and NP205, and I don’t think there was any 4WD light in the dash. I know my ‘75 K25 has no dash light for 4WD.
the NP203 , im unsure on the defining situation in what got it or not, had a LOCK or maybe it was HI LOCK light in place of 4wd. i think
The np205 also had a 4wd light starting some point
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
You must be registered for see images attach


"4 wheel lok"

You must be registered for see images attach

looks like np205 wasnt standard with that feature. my np205 (1980) is. but the 1977 Sm465/np205 I have, does not have a sensor on it
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
I assume they'd be the same, though there is a quite a bit of difference between the fuse panel on my '84 K1500 and '85 C10. I haven't looked at enough round eye squares to know if they'd be any different. With that said, if you're rewiring everything, you can use any fuse panel you want as long as there is enough slots for your application.
1979+ was blade fuses but the panel was different every couple of years. the engine bay side for the bulkhead connection changed a few times to match this evolution
The fuse panel I posted would be OE on his truck, but the glass fuse from 78 is a fine one
You must be registered for see images attach

this is the albeit ****** pic of my 78 k10s box, it got paint on it by my gpa many years ago lol. but its got more fuses than a 75 would
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,017
Reaction score
1,808
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
The 4WD Lok light listed in the ‘77 brochure really interests me. I would love to know what type of sensor they used to determine the shifter position on the NP203 and turn on the light.

Since my NP203 is unconverted, I just leave it in Hi position (AWD) all the time. I put it in the Hi-Lok position once or twice just to make sure it worked, but it’s been a long time.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
The 4WD Lok light listed in the ‘77 brochure really interests me. I would love to know what type of sensor they used to determine the shifter position on the NP203 and turn on the light.

Since my NP203 is unconverted, I just leave it in Hi position (AWD) all the time. I put it in the Hi-Lok position once or twice just to make sure it worked, but it’s been a long time.
You must be registered for see images attach


see the thing on the shifter assembly ? THe two wires run to a plug(prob connects to truck Id guess )
You must be registered for see images attach
 

Latest posts

Forum statistics

Threads
41,850
Posts
903,478
Members
33,362
Latest member
Dhatch84
Top