I picked up an 85 M1028 a few weeks ago. It has 37k miles and I paid 3.7k. So far have been very happy with the purchase, but I'm having some issues that have got me scratching my head.
The truck, as received, had non-functional glow plugs, no dash lights at all, and a Gen 1 belt that was too long/slipping really bad. I discovered the glow plug module was bad, I switched it with the known good module off my other truck. This gave me the glow plugs back but still no dash light. Eventually I found the heater fuse was popped. I replaced the fuse, and within five seconds of accessory key, it popped again. After four more fuses (while testing other various things trying to find the issue) It stopped popping the fuse on the fifth fuse. I regained dash lights and everything seemed to be operating correctly.
That was until I drove it around town for half an hour. When I returned I lost half of the dash lights. So now I have the "Wait" and "Water in fuel" lights, but lost the Gen 1 and Coolant lights. The bulbs are known good and have been eliminated . I am getting voltage from the cluster electrical connector to both circuits, so I don't believe it's the cluster. During the first round of diagnostics, all the grounds I could find were good (behind dash and both engine grounds). I also replaced the glow plug relay just incase (100% sure it's wired correctly). I should mention: the glow plug resistor has been bypassed and the relay is getting 12v from the top buss-bar.
There are things I have not been able to check because of weather. I suspect that Gen 1 is underperforming (Gen 2 is suspect also), so I will test both as soon as I can. Also, the two pin plug to Gen 1 is really gummed up and gross. I'll clean it up next time I get out there.
Is there something I am missing or should take a double look at?
Here's the truck.
The truck, as received, had non-functional glow plugs, no dash lights at all, and a Gen 1 belt that was too long/slipping really bad. I discovered the glow plug module was bad, I switched it with the known good module off my other truck. This gave me the glow plugs back but still no dash light. Eventually I found the heater fuse was popped. I replaced the fuse, and within five seconds of accessory key, it popped again. After four more fuses (while testing other various things trying to find the issue) It stopped popping the fuse on the fifth fuse. I regained dash lights and everything seemed to be operating correctly.
That was until I drove it around town for half an hour. When I returned I lost half of the dash lights. So now I have the "Wait" and "Water in fuel" lights, but lost the Gen 1 and Coolant lights. The bulbs are known good and have been eliminated . I am getting voltage from the cluster electrical connector to both circuits, so I don't believe it's the cluster. During the first round of diagnostics, all the grounds I could find were good (behind dash and both engine grounds). I also replaced the glow plug relay just incase (100% sure it's wired correctly). I should mention: the glow plug resistor has been bypassed and the relay is getting 12v from the top buss-bar.
There are things I have not been able to check because of weather. I suspect that Gen 1 is underperforming (Gen 2 is suspect also), so I will test both as soon as I can. Also, the two pin plug to Gen 1 is really gummed up and gross. I'll clean it up next time I get out there.
Is there something I am missing or should take a double look at?
Here's the truck.