[kait0sullivan]

Hello!

I'm a Service Advisor for a Ford dealership in a small town in Ontario, and our local Canada Post office frequently sends us their 1995 S10 postal vans. We mainly do a lot of driveline and suspension work for them, however they're coming in a lot more often with electrical issues, and we're trying to build a knowledge base of these vehicles to get them out of here quicker.

If anybody possibly has any wiring diagrams, service manual, electrical schematics, anything at all, I'd love to take a look!!

Thanks

 

[oldeerslayer]

Have you tried contacting Grumman, the final assembly builders? They must have done the majority of the wiring.
I thought Grumman only made them thru 1994, but that could have been just for the USPS. I'm sure Canada had a separate contract. 1995 electrical for the US S10 engines was a clusterflock. Some were OBD and some OBD2. By 1996 they were all OBD2, but still had some issues with trying to use the VCM to operate the ABS.

 

[manbearpig]

The postal vehicles were all 4 bangers, so 94 & 95 shouldn't be much different from each other.

 

[aitch]

Like oldeerslayer suggested, contacting Grumman may be your best bet for accurate data on the trucks, mechanically and electrically. I can't address how the Canadian Postal agency functions, but the USPS (along with lots of other federal agencies) has a pattern of imposing their own specifications onto a 'standard' production item. So while a year specific Factory Service Manual from GM might be helpful, I wouldn't be surprised if not everything matched a postal vehicle. And even GM had a fair number of their own 'tweaks'/ variations in the '95 S series truck. It was pretty much a one-off model year, as it was a design "in transition".

Here's a link for some of the s10 electrical info: S10 - Google Drive, which may be of some use.

 

[WadeSchweitzer]

I'm a retired USPS automotive tech. We refer to these vehicles as LLVs (Long Life Vehicles). '80s and early '90s model vehicles - still on the road - safely. They are 2.5L, except the '94 models, which are 2.2L. '94 is the last year model we had. (I'd love to swap a 4.3L into one that's been tricked out with HP 350cid parts. Full frame, all aluminum body, no weight to speak of. Talk about a "sleeper" with an aluminum box body - Slicks might give it away.) They are not tight; they rattle and have air leaks that the heater might be able to keep up with in Canada. They are just a basic OBD1 vehicle, don't really need a scanner - read the blink codes. Engine Wiring Harnesses are pretty much the same as the S10. Difference is under the Dash, Instrument Panel, and some of the Body wiring. Replacing wiper pivots is a P-I-T-A. With LLVs being an aging fleet, they are becoming more difficult to service. When I retired, we were beginning to see them come in for electrical problems that were difficult to diagnose. Replacing harnesses sometimes remedied the problem.
Go get yourself a Haynes Manual for the Gen1 S10s, or get yourself access to ALLDATA, ProDemand (or something similar). You might try to get your dealership's management to reach out to any USPS VMF (Vehicle Maintenance Facility). Make friends with one that's cooperative, maybe they will have an extra manual they can send you. Maybe they could copy and send you (or fax to you) info that you need.
Does the Canadian Post Office NOT have Vehicle Maintenance Facilities? Are they cheap? - farming their work out to you guys? Are they better at paying their bills than this side of the border?

 

[oldeerslayer]

I read the post office bought 99,000 of them and decided to retire them because by 2019 maintenance was up to $3000 per year per LLV. If my 8th grade math is correct that's just under $300 million a year. Now you know why the old penny postcard costs 44¢ to mail today.

 

[Gen210]